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• Uploading multiple files using Spring MVC 3.0.2 after HiddenHttpMethodFilter has been enabled

  - by Tiny

  I'm using Spring version 3.0.2. I need to upload multiple files using the multiple="multiple" attribute of a file browser such as, <input type="file" id="myFile" name="myFile" multiple="multiple"/> (and not using multiple file browsers something like the one stated by this answer, it indeed works I tried). Although no versions of Internet Explorer supports this approach unless an appropriate jQuery plugin/widget is used, I don't care about it right now (since most other browsers support this). This works fine with commons fileupload but in addition to using RequestMethod.POST and RequestMethod.GET methods, I also want to use other request methods supported and suggested by Spring like RequestMethod.PUT and RequestMethod.DELETE in their own appropriate places. For this to be so, I have configured Spring with HiddenHttpMethodFilter which goes fine as this question indicates. but it can upload only one file at a time even though multiple files in the file browser are chosen. In the Spring controller class, a method is mapped as follows. @RequestMapping(method={RequestMethod.POST}, value={"admin_side/Temp"}) public String onSubmit(@RequestParam("myFile") List<MultipartFile> files, @ModelAttribute("tempBean") TempBean tempBean, BindingResult error, Map model, HttpServletRequest request, HttpServletResponse response) throws IOException, FileUploadException { for(MultipartFile file:files) { System.out.println(file.getOriginalFilename()); } } Even with the request parameter @RequestParam("myFile") List<MultipartFile> files which is a List of type MultipartFile (it can always have only one file at a time). I could find a strategy which is likely to work with multiple files on this blog. I have gone through it carefully. The solution below the section SOLUTION 2 – USE THE RAW REQUEST says, If however the client insists on using the same form input name such as ‘files[]‘ or ‘files’ and then populating that name with multiple files then a small hack is necessary as follows. As noted above Spring 2.5 throws an exception if it detects the same form input name of type file more than once. CommonsFileUploadSupport – the class which throws that exception is not final and the method which throws that exception is protected so using the wonders of inheritance and subclassing one can simply fix/modify the logic a little bit as follows. The change I’ve made is literally one word representing one method invocation which enables us to have multiple files incoming under the same form input name. It attempts to override the method protected MultipartParsingResult parseFileItems(List fileItems, String encoding) {} of the abstract class CommonsFileUploadSupport by extending the class CommonsMultipartResolver such as, package multipartResolver; import java.io.UnsupportedEncodingException; import java.util.HashMap; import java.util.Iterator; import java.util.List; import java.util.Map; import javax.servlet.ServletContext; import org.apache.commons.fileupload.FileItem; import org.springframework.util.StringUtils; import org.springframework.web.multipart.MultipartException; import org.springframework.web.multipart.MultipartFile; import org.springframework.web.multipart.commons.CommonsMultipartFile; import org.springframework.web.multipart.commons.CommonsMultipartResolver; final public class MultiCommonsMultipartResolver extends CommonsMultipartResolver { public MultiCommonsMultipartResolver() { } public MultiCommonsMultipartResolver(ServletContext servletContext) { super(servletContext); } @Override @SuppressWarnings("unchecked") protected MultipartParsingResult parseFileItems(List fileItems, String encoding) { Map<String, MultipartFile> multipartFiles = new HashMap<String, MultipartFile>(); Map multipartParameters = new HashMap(); // Extract multipart files and multipart parameters. for (Iterator it = fileItems.iterator(); it.hasNext();) { FileItem fileItem = (FileItem) it.next(); if (fileItem.isFormField()) { String value = null; if (encoding != null) { try { value = fileItem.getString(encoding); } catch (UnsupportedEncodingException ex) { if (logger.isWarnEnabled()) { logger.warn("Could not decode multipart item '" + fileItem.getFieldName() + "' with encoding '" + encoding + "': using platform default"); } value = fileItem.getString(); } } else { value = fileItem.getString(); } String[] curParam = (String[]) multipartParameters.get(fileItem.getFieldName()); if (curParam == null) { // simple form field multipartParameters.put(fileItem.getFieldName(), new String[] { value }); } else { // array of simple form fields String[] newParam = StringUtils.addStringToArray(curParam, value); multipartParameters.put(fileItem.getFieldName(), newParam); } } else { // multipart file field CommonsMultipartFile file = new CommonsMultipartFile(fileItem); if (multipartFiles.put(fileItem.getName(), file) != null) { throw new MultipartException("Multiple files for field name [" + file.getName() + "] found - not supported by MultipartResolver"); } if (logger.isDebugEnabled()) { logger.debug("Found multipart file [" + file.getName() + "] of size " + file.getSize() + " bytes with original filename [" + file.getOriginalFilename() + "], stored " + file.getStorageDescription()); } } } return new MultipartParsingResult(multipartFiles, multipartParameters); } } What happens is that the last line in the method parseFileItems() (the return statement) i.e. return new MultipartParsingResult(multipartFiles, multipartParameters); causes a compile-time error because the first parameter multipartFiles is a type of Map implemented by HashMap but in reality, it requires a parameter of type MultiValueMap<String, MultipartFile> It is a constructor of a static class inside the abstract class CommonsFileUploadSupport, public abstract class CommonsFileUploadSupport { protected static class MultipartParsingResult { public MultipartParsingResult(MultiValueMap<String, MultipartFile> mpFiles, Map<String, String[]> mpParams) { } } } The reason might be - this solution is about the Spring version 2.5 and I'm using the Spring version 3.0.2 which might be inappropriate for this version. I however tried to replace the Map with MultiValueMap in various ways such as the one shown in the following segment of code, MultiValueMap<String, MultipartFile>mul=new LinkedMultiValueMap<String, MultipartFile>(); for(Entry<String, MultipartFile>entry:multipartFiles.entrySet()) { mul.add(entry.getKey(), entry.getValue()); } return new MultipartParsingResult(mul, multipartParameters); but no success. I'm not sure how to replace Map with MultiValueMap and even doing so could work either. After doing this, the browser shows the Http response, HTTP Status 400 - type Status report message description The request sent by the client was syntactically incorrect (). Apache Tomcat/6.0.26 I have tried to shorten the question as possible as I could and I haven't included unnecessary code. How could be made it possible to upload multiple files after Spring has been configured with HiddenHttpMethodFilter? That blog indicates that It is a long standing, high priority bug. If there is no solution regarding the version 3.0.2 (3 or higher) then I have to disable Spring support forever and continue to use commons-fileupolad as suggested by the third solution on that blog omitting the PUT, DELETE and other request methods forever. Just curiously waiting for a solution and/or suggestion. Very little changes to the code in the parseFileItems() method inside the class MultiCommonsMultipartResolver might make it to upload multiple files but I couldn't succeed in my attempts (again with the Spring version 3.0.2 (3 or higher)).

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• On screen orientation loads again data with Async Task

  - by Zookey

  I make Android application with master/detail pattern. So I have ListActivity class which is FragmentActivity and ListFragment class which is Fragment It all works perfect, but when I change screen orientation it calls again AsyncTask and reload all data. Here is the code for ListActivity class where I handle all logic: @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_list); getActionBar().setDisplayHomeAsUpEnabled(true); getActionBar().setHomeButtonEnabled(true); getActionBar().setTitle("Dnevni horoskop"); if(findViewById(R.id.details_container) != null){ //Tablet mTwoPane = true; //Fragment stuff FragmentManager fm = getSupportFragmentManager(); FragmentTransaction ft = fm.beginTransaction(); DetailsFragment df = new DetailsFragment(); ft.add(R.id.details_container, df); ft.commit(); } pb = (ProgressBar) findViewById(R.id.pb_list); tvNoConnection = (TextView) findViewById(R.id.tv_no_internet); ivNoConnection = (ImageView) findViewById(R.id.iv_no_connection); list = (GridView) findViewById(R.id.gv_list); if(mTwoPane == true){ list.setNumColumns(1); //list.setPadding(16,16,16,16); } adapter = new CustomListAdapter(); list.setOnItemClickListener(new OnItemClickListener() { @Override public void onItemClick(AdapterView<?> arg0, View arg1, int position, long arg3) { pos = position; if(mTwoPane == false){ Bundle bundle = new Bundle(); bundle.putSerializable("zodiac", zodiacFeed); Intent i = new Intent(getApplicationContext(), DetailsActivity.class); i.putExtra("position", position); i.putExtras(bundle); startActivity(i); overridePendingTransition(R.anim.right_in, R.anim.right_out); } else if(mTwoPane == true){ DetailsFragment fragment = (DetailsFragment) getSupportFragmentManager().findFragmentById(R.id.details_container); fragment.setHoroscopeText(zodiacFeed.getItem(position).getText()); fragment.setLargeImage(zodiacFeed.getItem(position).getLargeImage()); fragment.setSign("Dnevni horoskop - "+zodiacFeed.getItem(position).getName()); fragment.setSignDuration(zodiacFeed.getItem(position).getDuration()); // inflate menu from xml /*if(menu != null){ MenuItem item = menu.findItem(R.id.share); Toast.makeText(getApplicationContext(), item.getTitle().toString(), Toast.LENGTH_SHORT).show(); }*/ } } }); if(!Utils.isConnected(getApplicationContext())){ pb.setVisibility(View.GONE); tvNoConnection.setVisibility(View.VISIBLE); ivNoConnection.setVisibility(View.VISIBLE); } //Calling AsyncTask to load data Log.d("TAG", "loading"); HoroscopeAsyncTask task = new HoroscopeAsyncTask(pb); task.execute(); } @Override public void onConfigurationChanged(Configuration newConfig) { // TODO Auto-generated method stub super.onConfigurationChanged(newConfig); } class CustomListAdapter extends BaseAdapter { private LayoutInflater layoutInflater; public CustomListAdapter() { layoutInflater = (LayoutInflater) getBaseContext().getSystemService( Context.LAYOUT_INFLATER_SERVICE); } public int getCount() { // TODO Auto-generated method stub // Set the total list item count return names.length; } public Object getItem(int arg0) { // TODO Auto-generated method stub return null; } public long getItemId(int arg0) { // TODO Auto-generated method stub return 0; } public View getView(int position, View convertView, ViewGroup parent) { // Inflate the item layout and set the views View listItem = convertView; int pos = position; zodiacItem = zodiacList.get(pos); if (listItem == null && mTwoPane == false) { listItem = layoutInflater.inflate(R.layout.list_item, null); } else if(mTwoPane == true){ listItem = layoutInflater.inflate(R.layout.tablet_list_item, null); } // Initialize the views in the layout ImageView iv = (ImageView) listItem.findViewById(R.id.iv_horoscope); iv.setScaleType(ScaleType.CENTER_CROP); TextView tvName = (TextView) listItem.findViewById(R.id.tv_zodiac_name); TextView tvDuration = (TextView) listItem.findViewById(R.id.tv_duration); iv.setImageResource(zodiacItem.getImage()); tvName.setText(zodiacItem.getName()); tvDuration.setText(zodiacItem.getDuration()); Animation animation = AnimationUtils.loadAnimation(getBaseContext(), R.anim.push_up); listItem.startAnimation(animation); animation = null; return listItem; } } private void getHoroscope() { String urlString = "http://balkanandroid.com/download/horoskop/examples/dnevnihoroskop.php"; try { HttpClient client = new DefaultHttpClient(); HttpPost post = new HttpPost(urlString); HttpResponse response = client.execute(post); resEntity = response.getEntity(); response_str = EntityUtils.toString(resEntity); if (resEntity != null) { Log.i("RESPONSE", response_str); runOnUiThread(new Runnable() { public void run() { try { Log.d("TAG", "Response from server : n " + response_str); } catch (Exception e) { e.printStackTrace(); } } }); } } catch (Exception ex) { Log.e("TAG", "error: " + ex.getMessage(), ex); } } private class HoroscopeAsyncTask extends AsyncTask<String, Void, Void> { public HoroscopeAsyncTask(ProgressBar pb1){ pb = pb1; } @Override protected void onPreExecute() { pb.setVisibility(View.VISIBLE); super.onPreExecute(); } @Override protected Void doInBackground(String... params) { getHoroscope(); try { Log.d("TAG", "test u try"); JSONObject jsonObject = new JSONObject(response_str); JSONArray jsonArray = jsonObject.getJSONArray("horoscope"); for(int i=0;i<jsonArray.length();i++){ Log.d("TAG", "test u for"); JSONObject horoscopeObj = jsonArray.getJSONObject(i); String horoscopeSign = horoscopeObj.getString("name_sign"); String horoscopeText = horoscopeObj.getString("txt_hrs"); zodiacItem = new ZodiacItem(horoscopeSign, horoscopeText, duration[i], images[i], largeImages[i]); zodiacList.add(zodiacItem); zodiacFeed.addItem(zodiacItem); //Treba u POJO klasu ubaciti sve. Log.d("TAG", "ZNAK: "+zodiacItem.getName()+" HOROSKOP: "+zodiacItem.getText()); } } catch (JSONException e) { // TODO Auto-generated catch block e.printStackTrace(); Log.e("TAG", "error: " + e.getMessage(), e); } return null; } @Override protected void onPostExecute(Void result) { pb.setVisibility(View.GONE); list.setAdapter(adapter); adapter.notifyDataSetChanged(); super.onPostExecute(result); } } Here is the code for ListFragment class: public class ListFragment extends Fragment { @Override public void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub // Retain this fragment across configuration changes. setRetainInstance(true); super.onCreate(savedInstanceState); } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { // TODO Auto-generated method stub View view = inflater.inflate(R.layout.fragment_list, container, false); return view; } }

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• questions regarding the use of A* with the 15-square puzzle

  - by Cheeso

  I'm trying to build an A* solver for a 15-square puzzle. The goal is to re-arrange the tiles so that they appear in their natural positions. You can only slide one tile at a time. Each possible state of the puzzle is a node in the search graph. For the h(x) function, I am using an aggregate sum, across all tiles, of the tile's dislocation from the goal state. In the above image, the 5 is at location 0,0, and it belongs at location 1,0, therefore it contributes 1 to the h(x) function. The next tile is the 11, located at 0,1, and belongs at 2,2, therefore it contributes 3 to h(x). And so on. EDIT: I now understand this is what they call "Manhattan distance", or "taxicab distance". I have been using a step count for g(x). In my implementation, for any node in the state graph, g is just +1 from the prior node's g. To find successive nodes, I just examine where I can possibly move the "hole" in the puzzle. There are 3 neighbors for the puzzle state (aka node) that is displayed: the hole can move north, west, or east. My A* search sometimes converges to a solution in 20s, sometimes 180s, and sometimes doesn't converge at all (waited 10 mins or more). I think h is reasonable. I'm wondering if I've modeled g properly. In other words, is it possible that my A* function is reaching a node in the graph via a path that is not the shortest path? Maybe have I not waited long enough? Maybe 10 minutes is not long enough? For a fully random arrangement, (assuming no parity problems), What is the average number of permutations an A* solution will examine? (please show the math) I'm going to look for logic errors in my code, but in the meantime, Any tips? (ps: it's done in Javascript). Also, no, this isn't CompSci homework. It's just a personal exploration thing. I'm just trying to learn Javascript. EDIT: I've found that the run-time is highly depend upon the heuristic. I saw the 10x factor applied to the heuristic from the article someone mentioned, and it made me wonder - why 10x? Why linear? Because this is done in javascript, I could modify the code to dynamically update an html table with the node currently being considered. This allowd me to peek at the algorithm as it was progressing. With a regular taxicab distance heuristic, I watched as it failed to converge. There were 5's and 12's in the top row, and they kept hanging around. I'd see 1,2,3,4 creep into the top row, but then they'd drop out, and other numbers would move up there. What I was hoping to see was 1,2,3,4 sort of creeping up to the top, and then staying there. I thought to myself - this is not the way I solve this personally. Doing this manually, I solve the top row, then the 2ne row, then the 3rd and 4th rows sort of concurrently. So I tweaked the h(x) function to more heavily weight the higher rows and the "lefter" columns. The result was that the A* converged much more quickly. It now runs in 3 minutes instead of "indefinitely". With the "peek" I talked about, I can see the smaller numbers creep up to the higher rows and stay there. Not only does this seem like the right thing, it runs much faster. I'm in the process of trying a bunch of variations. It seems pretty clear that A* runtime is very sensitive to the heuristic. Currently the best heuristic I've found uses the summation of dislocation * ((4-i) + (4-j)) where i and j are the row and column, and dislocation is the taxicab distance. One interesting part of the result I got: with a particular heuristic I find a path very quickly, but it is obviously not the shortest path. I think this is because I am weighting the heuristic. In one case I got a path of 178 steps in 10s. My own manual effort produce a solution in 87 moves. (much more than 10s). More investigation warranted. So the result is I am seeing it converge must faster, and the path is definitely not the shortest. I have to think about this more. Code: var stop = false; function Astar(start, goal, callback) { // start and goal are nodes in the graph, represented by // an array of 16 ints. The goal is: [1,2,3,...14,15,0] // Zero represents the hole. // callback is a method to call when finished. This runs a long time, // therefore we need to use setTimeout() to break it up, to avoid // the browser warning like "Stop running this script?" // g is the actual distance traveled from initial node to current node. // h is the heuristic estimate of distance from current to goal. stop = false; start.g = start.dontgo = 0; // calcHeuristic inserts an .h member into the array calcHeuristicDistance(start); // start the stack with one element var closed = []; // set of nodes already evaluated. var open = [ start ]; // set of nodes to evaluate (start with initial node) var iteration = function() { if (open.length==0) { // no more nodes. Fail. callback(null); return; } var current = open.shift(); // get highest priority node // update the browser with a table representation of the // node being evaluated $("#solution").html(stateToString(current)); // check solution returns true if current == goal if (checkSolution(current,goal)) { // reconstructPath just records the position of the hole // through each node var path= reconstructPath(start,current); callback(path); return; } closed.push(current); // get the set of neighbors. This is 3 or fewer nodes. // (nextStates is optimized to NOT turn directly back on itself) var neighbors = nextStates(current, goal); for (var i=0; i<neighbors.length; i++) { var n = neighbors[i]; // skip this one if we've already visited it if (closed.containsNode(n)) continue; // .g, .h, and .previous get assigned implicitly when // calculating neighbors. n.g is nothing more than // current.g+1 ; // add to the open list if (!open.containsNode(n)) { // slot into the list, in priority order (minimum f first) open.priorityPush(n); n.previous = current; } } if (stop) { callback(null); return; } setTimeout(iteration, 1); }; // kick off the first iteration iteration(); return null; }

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• wrong return value with jquery ajax and codeigniter

  - by matthew

  I do not know if this is specifically a jquery problem, actually I think it has to mostly do with my logic in the php code. What Im trying to do is make a voting system that when the user clicks on the vote up or vote down link in the web page, it triggers an ajax call to a php function that first updates the database with with the required value, on success of the database updating the another function is called just to get the required updated html for the that particular post that the user has voted on. (hope I havnt lost you). The problem I think deals with specifically with this one line of code. When I make the call it only returns the value of $row-beer_down and completly ignores everything else in that line. Funny thing is the same php code to display the html view works perfectly before the ajax function updates it. echo "<p>Score " . $row->beer_up + $row->beer_down . "</p>"; so here is the code to hope you can help as I have absolutely no idea how to fix this. here is the view file where it generates the page. This part is the query ajax function. <script type="text/javascript"> $(function() { $(".vote").click(function(){ var id = $(this).attr("id"); var name = $(this).attr("name"); var dataString = 'id='+ id ; var parent = $(this); if(name=='up') { $.ajax({ type: "POST", url: "http://127.0.0.1/CodeIgniter/blog/add_vote/" + id, data: dataString, cache: false, success: function(html) { //parent.html(html); $("." + id).load('http://127.0.0.1/CodeIgniter/blog/get_post/' + id).fadeIn("slow"); } }); } else { $.ajax({ type: "POST", url: "http://127.0.0.1/CodeIgniter/blog/minus_vote/" + id, data: dataString, cache: false, success: function(html) { //parent.html(html); $("." + id).load('http://127.0.0.1/CodeIgniter/blog/get_post/' + id).fadeIn("slow"); } }); } return false; }); }); </script> Here is the html and php part of the page to display the post. div id="post_container"> <?php //echo $this->table->generate($records); ?> <?php foreach($records->result() as $row) { ?> <?php echo "<div id=\"post\" class=\"" . $row->id . "\">"; ?> <h2><?php echo $row->id ?></h2> <?php echo "<img src=\"" . base_url() . $dir . $row->account_id . "/" . $row->file_name . "\">" ?> <p><?php echo $row->content ?></p> <p><?php echo $row->user_name ?> On <?php echo $row->time ?></p> <p>Score <?php echo $row->beer_up + $row->beer_down ?></p> <?php echo anchor('blog/add_vote/' . $row->id, 'Up Vote', array('class' => 'vote', 'id' => $row->id, 'name' => 'up')); echo anchor('blog/minus_vote/' . $row->id, 'Down Vote', array('class' => 'vote', 'id' => $row->id, 'name' => 'down')); echo anchor('blog/comments/' . $row->id, 'View Comments'); ?> </div> <?php } ?> here is the function the ajax calls when it is successfull: function get_post() { $this->db->where('id', $this->uri->segment(3)); $records = $this->db->get('post'); $dir = "/uploads/user_uploads/"; foreach($records->result() as $row) { echo "<div id=\"post\" class=\"" . $row->id . "\">"; echo "<h2>" . $row->id . "</h2>"; echo "<img src=\"" . base_url() . $dir . $row->account_id . "/" . $row->file_name . "\">"; echo "<p>" . $row->content . "</p>"; echo "<p>" . $row->user_name . " On " . $row->time . "</p>"; echo "<p>Score " . $row->beer_up + $row->beer_down . "</p>"; echo "<p>Up score" . $row->beer_up . "beer down" . $row->beer_down . "</p>"; echo anchor('blog/comments/' . $row->id, 'View Comments'); echo "</div>"; }

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• Databinding, using formulas for unusual binding possible?

  - by Rattenmann

  Edit: added Info for WPF being used I am trying to bind a list of custom objects to a DataGrid. Straight binding seems easy enough, but i need to specify some complex formulas for some extra fields that do not directly show up in my class. Also i want to be able to EDIT the data in the Grid and get updates on related fields. Let me show you an example, because it is really hard to explain. I will simplify it to rooms with items. Each item can be red and blue. My Class looks like this: public class room { public string strRoomName { set; get; } public string strItemname { set; get; } public int intRedItem { set; get; } public int intBlueItem { set; get; } } Now if i use dataTable.ItemSource = myList; i get something like this: nr. | room | name | red | blue 1. living room, ball, 2, 1 2. sleeping room, bunny, 4, 1 3. living room, chair, 3, 2 4. kitchen, ball, 4, 7 5. garage, chair, 1, 4 Now for the complex part i need help with. I want every item to be the same number, red and blue. And because this does not hold true i want to see the "inbalance" per room AND globally like this: nr. | room | name | red | blue | missing | global red | global blue | global missing 1. living room, ball, 2, 1, 1 blue, 6, 7, 1 red 2. sleeping room, bunny, 4, 1, 3 blue, 4, 1, 3 blue 3. living room, chair, 3, 2, 1 blue, 4, 6, 2 red 4. kitchen, ball, 4, 7, 3 red, 6, 7, 1 red 5. garage, chair, 1, 4, 3 red, 4, 6, 2 red As you can see this smeels like excel formulas, i am unsure how to handle this in c# code however. You can also see i need to use data in the same row, but also get data from other rows that match one propertiy (the items name). Also if i change the blue value=1 in line 1 to value=2, i want line 1 to read like this: 1. living room, ball, 2, 2, even, 6, 8, 2 red and of corse line 4 needs to change to: 4. kitchen, ball, 4, 7, 3 red, 6, 8, 2 red As i said, this smells like excel, that's why i am really upset about myself not finding an easy solution. Surely enough c# offers some way to handle this stuff, right? Disclaimer: It is totally possible that i need a complete differend approach, pointing that out ot me is perfectly fine. Be it other ways to handle this, or a better way to structure my class. I am ok with every way to handle this as it is for learning purposes. I am simply doing programms for fun next to my college and just so happen to hit these kinda things that bug me out because i don't find a clean solution. And then i neglect my studies because i want to solve my (unreleated to studys,...) issue. Just can't stand having unsolved coding stuff around, don't judge me! ;-) And big thanks in advance if you have gotten this far in my post. It sure must be confusing with all those reds and blues. Edit: After reading trough your answers and testing my skills to implement your hints, i now have the following code as my class: public class RoomList : ObservableCollection<room> { public RoomList() : base() { Add(new room() { strRoomName = "living room", strItemname = "ball", intRedItem = 2, intBlueItem = 1 }); Add(new room() { strRoomName = "sleeping room", strItemname = "bunny", intRedItem = 4, intBlueItem = 1 }); Add(new room() { strRoomName = "living room", strItemname = "chair", intRedItem = 3, intBlueItem = 2 }); Add(new room() { strRoomName = "kitchen", strItemname = "ball", intRedItem = 4, intBlueItem = 7 }); Add(new room() { strRoomName = "garage", strItemname = "chair", intRedItem = 1, intBlueItem = 4 }); } } //rooms public class room : INotifyPropertyChanged { public string strRoomName { set; get; } public string strItemname { set; get; } public int intRedItem { get { return intRedItem; } set { intRedItem = value; NotifyPropertyChanged("intRedItem", "strMissing"); } } public int intBlueItem { get { return intBlueItem; } set { intBlueItem = value; NotifyPropertyChanged("intBlueItem", "strMissing"); } } public string strMissing { get { int missingCount = intRedItem - intBlueItem; return missingCount == 0 ? "Even" : missingCount.ToString(); } } public event PropertyChangedEventHandler PropertyChanged; public void NotifyPropertyChanged(params string[] propertyNames) { if (PropertyChanged != null) { foreach (string propertyName in propertyNames) { PropertyChanged(this, new PropertyChangedEventArgs(propertyName)); } } } } I got the "missing" field working right away, thanks alot for that tip. It really was as easy as i imagined and will be of great use for future projects. Still two (three maybe....) things i am missing tho. The above code terminates with a "System.StackOverflowException" in the setter of intRedItem and intBlueItem. I fail to see the error, that could be due to being 4:30am here, or my lack of understanding. Second issue: I followed the link to ObservableCollections as you can see from my code above. Yet i am unsure how to actually use that collection. Putting it as DataContent like suggested on that page shows a missing ressource. Adding it as a ressource like listed there crashes my VSExpress designer and leads to the programm not starting. So for now i am still using my old approach of a list like this: listRooms.Add(new room() { strRoomName = "living room", strItemname = "ball", intRedItem = 2, intBlueItem = 1 }); listRooms.Add(new room() { strRoomName = "sleeping room", strItemname = "bunny", intRedItem = 4, intBlueItem = 1 }); listRooms.Add(new room() { strRoomName = "living room", strItemname = "chair", intRedItem = 3, intBlueItem = 2 }); listRooms.Add(new room() { strRoomName = "kitchen", strItemname = "ball", intRedItem = 4, intBlueItem = 7 }); listRooms.Add(new room() { strRoomName = "garage", strItemname = "chair", intRedItem = 1, intBlueItem = 4 }); datagridRooms.ItemsSource = listRooms; And lastly: When testing before adding the notifyevents i tried to implement a proterty that looped trough the other objects, without any luck. The "missingItem" property worked so easy, yet it only tries to access "it's own" properties kind of. I need to access other objects, like "all objects that have the same room value". The idea behind this is that i am trying to calculate a value from other objects without even having those objects yet, at least in my logic. Where is the flaw in my thinking? Those 5 objects are added and created (?) one after another. So if the first tries to set it's "all red balls in my room AND all other rooms" value,.. how could it know about the balls in the kitchen, that get added as 4th object? So far so good tho, got on the right track i think. Just need some sleep first.

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• Strange (Undefined?) Behavior of Free in C

  - by Chris Cirefice

  This is really strange... and I can't debug it (tried for about two hours, debugger starts going haywire after a while...). Anyway, I'm trying to do something really simple: Free an array of strings. The array is in the form: char **myStrings. The array elements are initialized as: myString[index] = malloc(strlen(word)); myString[index] = word; and I'm calling a function like this: free_memory(myStrings, size); where size is the length of the array (I know this is not the problem, I tested it extensively and everything except this function is working). free_memory looks like this: void free_memory(char **list, int size) { for (int i = 0; i < size; i ++) { free(list[i]); } free(list); } Now here comes the weird part. if (size> strlen(list[i])) then the program crashes. For example, imagine that I have a list of strings that looks something like this: myStrings[0] = "Some"; myStrings[1] = "random"; myStrings[2] = "strings"; And thus the length of this array is 3. If I pass this to my free_memory function, strlen(myStrings[0]) > 3 (4 3), and the program crashes. However, if I change myStrings[0] to be "So" instead, then strlen(myStrings[0]) < 3 (2 < 3) and the program does not crash. So it seems to me that free(list[i]) is actually going through the char[] that is at that location and trying to free each character, which I imagine is undefined behavior. The only reason I say this is because I can play around with the size of the first element of myStrings and make the program crash whenever I feel like it, so I'm assuming that this is the problem area. Note: I did try to debug this by stepping through the function that calls free_memory, noting any weird values and such, but the moment I step into the free_memory function, the debugger crashes, so I'm not really sure what is going on. Nothing is out of the ordinary until I enter the function, then the world explodes. Another note: I also posted the shortened version of the source for this program (not too long; Pastebin) here. I am compiling on MinGW with the c99 flag on. PS - I just thought of this. I am indeed passing numUniqueWords to the free function, and I know that this does not actually free the entire piece of memory that I allocated. I've called it both ways, that's not the issue. And I left it how I did because that is the way that I will be calling it after I get it to work in the first place, I need to revise some of my logic in that function. Source, as per request (on-site): #include <stdio.h> #include <string.h> #include <ctype.h> #include <stdlib.h> #include "words.h" int getNumUniqueWords(char text[], int size); int main(int argc, char* argv[]) { setvbuf(stdout, NULL, 4, _IONBF); // For Eclipse... stupid bug. --> does NOT affect the program, just the output to console! int nbr_words; char text[] = "Some - \"text, a stdin\". We'll have! also repeat? We'll also have a repeat!"; int length = sizeof(text); nbr_words = getNumUniqueWords(text, length); return 0; } void free_memory(char **list, int size) { for (int i = 0; i < size; i ++) { // You can see that printing the values is fine, as long as free is not called. // When free is called, the program will crash if (size > strlen(list[i])) //printf("Wanna free value %d w/len of %d: %s\n", i, strlen(list[i]), list[i]); free(list[i]); } free(list); } int getNumUniqueWords(char text[], int length) { int numTotalWords = 0; char *word; printf("Length: %d characters\n", length); char totalWords[length]; strcpy(totalWords, text); word = strtok(totalWords, " ,.-!?()\"0123456789"); while (word != NULL) { numTotalWords ++; printf("%s\n", word); word = strtok(NULL, " ,.-!?()\"0123456789"); } printf("Looks like we counted %d total words\n\n", numTotalWords); char *uniqueWords[numTotalWords]; char *tempWord; int wordAlreadyExists = 0; int numUniqueWords = 0; char totalWordsCopy[length]; strcpy(totalWordsCopy, text); for (int i = 0; i < numTotalWords; i++) { uniqueWords[i] = NULL; } // Tokenize until all the text is consumed. word = strtok(totalWordsCopy, " ,.-!?()\"0123456789"); while (word != NULL) { // Look through the word list for the current token. for (int j = 0; j < numTotalWords; j ++) { // Just for clarity, no real meaning. tempWord = uniqueWords[j]; // The word list is either empty or the current token is not in the list. if (tempWord == NULL) { break; } //printf("Comparing (%s) with (%s)\n", tempWord, word); // If the current token is the same as the current element in the word list, mark and break if (strcmp(tempWord, word) == 0) { printf("\nDuplicate: (%s)\n\n", word); wordAlreadyExists = 1; break; } } // Word does not exist, add it to the array. if (!wordAlreadyExists) { uniqueWords[numUniqueWords] = malloc(strlen(word)); uniqueWords[numUniqueWords] = word; numUniqueWords ++; printf("Unique: %s\n", word); } // Reset flags and continue. wordAlreadyExists = 0; word = strtok(NULL, " ,.-!?()\"0123456789"); } // Print out the array just for funsies - make sure it's working properly. for (int x = 0; x <numUniqueWords; x++) { printf("Unique list %d: %s\n", x, uniqueWords[x]); } printf("\nNumber of unique words: %d\n\n", numUniqueWords); // Right below is where things start to suck. free_memory(uniqueWords, numUniqueWords); return numUniqueWords; }

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• What's New in ASP.NET 4

  - by Navaneeth

  The .NET Framework version 4 includes enhancements for ASP.NET 4 in targeted areas. Visual Studio 2010 and Microsoft Visual Web Developer Express also include enhancements and new features for improved Web development. This document provides an overview of many of the new features that are included in the upcoming release. This topic contains the following sections: ASP.NET Core Services ASP.NET Web Forms ASP.NET MVC Dynamic Data ASP.NET Chart Control Visual Web Developer Enhancements Web Application Deployment with Visual Studio 2010 Enhancements to ASP.NET Multi-Targeting ASP.NET Core Services ASP.NET 4 introduces many features that improve core ASP.NET services such as output caching and session state storage. Extensible Output Caching Since the time that ASP.NET 1.0 was released, output caching has enabled developers to store the generated output of pages, controls, and HTTP responses in memory. On subsequent Web requests, ASP.NET can serve content more quickly by retrieving the generated output from memory instead of regenerating the output from scratch. However, this approach has a limitation — generated content always has to be stored in memory. On servers that experience heavy traffic, the memory requirements for output caching can compete with memory requirements for other parts of a Web application. ASP.NET 4 adds extensibility to output caching that enables you to configure one or more custom output-cache providers. Output-cache providers can use any storage mechanism to persist HTML content. These storage options can include local or remote disks, cloud storage, and distributed cache engines. Output-cache provider extensibility in ASP.NET 4 lets you design more aggressive and more intelligent output-caching strategies for Web sites. For example, you can create an output-cache provider that caches the "Top 10" pages of a site in memory, while caching pages that get lower traffic on disk. Alternatively, you can cache every vary-by combination for a rendered page, but use a distributed cache so that the memory consumption is offloaded from front-end Web servers. You create a custom output-cache provider as a class that derives from the OutputCacheProvider type. You can then configure the provider in the Web.config file by using the new providers subsection of the outputCache element For more information and for examples that show how to configure the output cache, see outputCache Element for caching (ASP.NET Settings Schema). For more information about the classes that support caching, see the documentation for the OutputCache and OutputCacheProvider classes. By default, in ASP.NET 4, all HTTP responses, rendered pages, and controls use the in-memory output cache. The defaultProvider attribute for ASP.NET is AspNetInternalProvider. You can change the default output-cache provider used for a Web application by specifying a different provider name for defaultProvider attribute. In addition, you can select different output-cache providers for individual control and for individual requests and programmatically specify which provider to use. For more information, see the HttpApplication.GetOutputCacheProviderName(HttpContext) method. The easiest way to choose a different output-cache provider for different Web user controls is to do so declaratively by using the new providerName attribute in a page or control directive, as shown in the following example: <%@ OutputCache Duration="60" VaryByParam="None" providerName="DiskCache" %> Preloading Web Applications Some Web applications must load large amounts of data or must perform expensive initialization processing before serving the first request. In earlier versions of ASP.NET, for these situations you had to devise custom approaches to "wake up" an ASP.NET application and then run initialization code during the Application_Load method in the Global.asax file. To address this scenario, a new application preload manager (autostart feature) is available when ASP.NET 4 runs on IIS 7.5 on Windows Server 2008 R2. The preload feature provides a controlled approach for starting up an application pool, initializing an ASP.NET application, and then accepting HTTP requests. It lets you perform expensive application initialization prior to processing the first HTTP request. For example, you can use the application preload manager to initialize an application and then signal a load-balancer that the application was initialized and ready to accept HTTP traffic. To use the application preload manager, an IIS administrator sets an application pool in IIS 7.5 to be automatically started by using the following configuration in the applicationHost.config file: <applicationPools> <add name="MyApplicationPool" startMode="AlwaysRunning" /> </applicationPools> Because a single application pool can contain multiple applications, you specify individual applications to be automatically started by using the following configuration in the applicationHost.config file: <sites> <site name="MySite" id="1"> <application path="/" serviceAutoStartEnabled="true" serviceAutoStartProvider="PrewarmMyCache" > <!-- Additional content --> </application> </site> </sites> <!-- Additional content --> <serviceAutoStartProviders> <add name="PrewarmMyCache" type="MyNamespace.CustomInitialization, MyLibrary" /> </serviceAutoStartProviders> When an IIS 7.5 server is cold-started or when an individual application pool is recycled, IIS 7.5 uses the information in the applicationHost.config file to determine which Web applications have to be automatically started. For each application that is marked for preload, IIS7.5 sends a request to ASP.NET 4 to start the application in a state during which the application temporarily does not accept HTTP requests. When it is in this state, ASP.NET instantiates the type defined by the serviceAutoStartProvider attribute (as shown in the previous example) and calls into its public entry point. You create a managed preload type that has the required entry point by implementing the IProcessHostPreloadClient interface, as shown in the following example: public class CustomInitialization : System.Web.Hosting.IProcessHostPreloadClient { public void Preload(string[] parameters) { // Perform initialization. } } After your initialization code runs in the Preload method and after the method returns, the ASP.NET application is ready to process requests. Permanently Redirecting a Page Content in Web applications is often moved over the lifetime of the application. This can lead to links to be out of date, such as the links that are returned by search engines. In ASP.NET, developers have traditionally handled requests to old URLs by using the Redirect method to forward a request to the new URL. However, the Redirect method issues an HTTP 302 (Found) response (which is used for a temporary redirect). This results in an extra HTTP round trip. ASP.NET 4 adds a RedirectPermanent helper method that makes it easy to issue HTTP 301 (Moved Permanently) responses, as in the following example: RedirectPermanent("/newpath/foroldcontent.aspx"); Search engines and other user agents that recognize permanent redirects will store the new URL that is associated with the content, which eliminates the unnecessary round trip made by the browser for temporary redirects. Session State Compression By default, ASP.NET provides two options for storing session state across a Web farm. The first option is a session state provider that invokes an out-of-process session state server. The second option is a session state provider that stores data in a Microsoft SQL Server database. Because both options store state information outside a Web application's worker process, session state has to be serialized before it is sent to remote storage. If a large amount of data is saved in session state, the size of the serialized data can become very large. ASP.NET 4 introduces a new compression option for both kinds of out-of-process session state providers. By using this option, applications that have spare CPU cycles on Web servers can achieve substantial reductions in the size of serialized session state data. You can set this option using the new compressionEnabled attribute of the sessionState element in the configuration file. When the compressionEnabled configuration option is set to true, ASP.NET compresses (and decompresses) serialized session state by using the .NET Framework GZipStreamclass. The following example shows how to set this attribute. <sessionState mode="SqlServer" sqlConnectionString="data source=dbserver;Initial Catalog=aspnetstate" allowCustomSqlDatabase="true" compressionEnabled="true" /> ASP.NET Web Forms Web Forms has been a core feature in ASP.NET since the release of ASP.NET 1.0. Many enhancements have been in this area for ASP.NET 4, such as the following: The ability to set meta tags. More control over view state. Support for recently introduced browsers and devices. Easier ways to work with browser capabilities. Support for using ASP.NET routing with Web Forms. More control over generated IDs. The ability to persist selected rows in data controls. More control over rendered HTML in the FormView and ListView controls. Filtering support for data source controls. Enhanced support for Web standards and accessibility Setting Meta Tags with the Page.MetaKeywords and Page.MetaDescription Properties Two properties have been added to the Page class: MetaKeywords and MetaDescription. These two properties represent corresponding meta tags in the HTML rendered for a page, as shown in the following example: <head id="Head1" runat="server"> <title>Untitled Page</title> <meta name="keywords" content="keyword1, keyword2' /> <meta name="description" content="Description of my page" /> </head> These two properties work like the Title property does, and they can be set in the @ Page directive. For more information, see Page.MetaKeywords and Page.MetaDescription. Enabling View State for Individual Controls A new property has been added to the Control class: ViewStateMode. You can use this property to disable view state for all controls on a page except those for which you explicitly enable view state. View state data is included in a page's HTML and increases the amount of time it takes to send a page to the client and post it back. Storing more view state than is necessary can cause significant decrease in performance. In earlier versions of ASP.NET, you could reduce the impact of view state on a page's performance by disabling view state for specific controls. But sometimes it is easier to enable view state for a few controls that need it instead of disabling it for many that do not need it. For more information, see Control.ViewStateMode. Support for Recently Introduced Browsers and Devices ASP.NET includes a feature that is named browser capabilities that lets you determine the capabilities of the browser that a user is using. Browser capabilities are represented by the HttpBrowserCapabilities object which is stored in the HttpRequest.Browser property. Information about a particular browser's capabilities is defined by a browser definition file. In ASP.NET 4, these browser definition files have been updated to contain information about recently introduced browsers and devices such as Google Chrome, Research in Motion BlackBerry smart phones, and Apple iPhone. Existing browser definition files have also been updated. For more information, see How to: Upgrade an ASP.NET Web Application to ASP.NET 4 and ASP.NET Web Server Controls and Browser Capabilities. The browser definition files that are included with ASP.NET 4 are shown in the following list: •blackberry.browser •chrome.browser •Default.browser •firefox.browser •gateway.browser •generic.browser •ie.browser •iemobile.browser •iphone.browser •opera.browser •safari.browser A New Way to Define Browser Capabilities ASP.NET 4 includes a new feature referred to as browser capabilities providers. As the name suggests, this lets you build a provider that in turn lets you write custom code to determine browser capabilities. In ASP.NET version 3.5 Service Pack 1, you define browser capabilities in an XML file. This file resides in a machine-level folder or an application-level folder. Most developers do not need to customize these files, but for those who do, the provider approach can be easier than dealing with complex XML syntax. The provider approach makes it possible to simplify the process by implementing a common browser definition syntax, or a database that contains up-to-date browser definitions, or even a Web service for such a database. For more information about the new browser capabilities provider, see the What's New for ASP.NET 4 White Paper. Routing in ASP.NET 4 ASP.NET 4 adds built-in support for routing with Web Forms. Routing is a feature that was introduced with ASP.NET 3.5 SP1 and lets you configure an application to use URLs that are meaningful to users and to search engines because they do not have to specify physical file names. This can make your site more user-friendly and your site content more discoverable by search engines. For example, the URL for a page that displays product categories in your application might look like the following example: http://website/products.aspx?categoryid=12 By using routing, you can use the following URL to render the same information: http://website/products/software The second URL lets the user know what to expect and can result in significantly improved rankings in search engine results. the new features include the following: The PageRouteHandler class is a simple HTTP handler that you use when you define routes. You no longer have to write a custom route handler. The HttpRequest.RequestContext and Page.RouteData properties make it easier to access information that is passed in URL parameters. The RouteUrl expression provides a simple way to create a routed URL in markup. The RouteValue expression provides a simple way to extract URL parameter values in markup. The RouteParameter class makes it easier to pass URL parameter values to a query for a data source control (similar to FormParameter). You no longer have to change the Web.config file to enable routing. For more information about routing, see the following topics: ASP.NET Routing Walkthrough: Using ASP.NET Routing in a Web Forms Application How to: Define Routes for Web Forms Applications How to: Construct URLs from Routes How to: Access URL Parameters in a Routed Page Setting Client IDs The new ClientIDMode property makes it easier to write client script that references HTML elements rendered for server controls. Increasing use of Microsoft Ajax makes the need to do this more common. For example, you may have a data control that renders a long list of products with prices and you want to use client script to make a Web service call and update individual prices in the list as they change without refreshing the entire page. Typically you get a reference to an HTML element in client script by using the document.GetElementById method. You pass to this method the value of the id attribute of the HTML element you want to reference. In the case of elements that are rendered for ASP.NET server controls earlier versions of ASP.NET could make this difficult or impossible. You were not always able to predict what id values ASP.NET would generate, or ASP.NET could generate very long id values. The problem was especially difficult for data controls that would generate multiple rows for a single instance of the control in your markup. ASP.NET 4 adds two new algorithms for generating id attributes. These algorithms can generate id attributes that are easier to work with in client script because they are more predictable and that are easier to work with because they are simpler. For more information about how to use the new algorithms, see the following topics: ASP.NET Web Server Control Identification Walkthrough: Making Data-Bound Controls Easier to Access from JavaScript Walkthrough: Making Controls Located in Web User Controls Easier to Access from JavaScript How to: Access Controls from JavaScript by ID Persisting Row Selection in Data Controls The GridView and ListView controls enable users to select a row. In previous versions of ASP.NET, row selection was based on the row index on the page. For example, if you select the third item on page 1 and then move to page 2, the third item on page 2 is selected. In most cases, is more desirable not to select any rows on page 2. ASP.NET 4 supports Persisted Selection, a new feature that was initially supported only in Dynamic Data projects in the .NET Framework 3.5 SP1. When this feature is enabled, the selected item is based on the row data key. This means that if you select the third row on page 1 and move to page 2, nothing is selected on page 2. When you move back to page 1, the third row is still selected. This is a much more natural behavior than the behavior in earlier versions of ASP.NET. Persisted selection is now supported for the GridView and ListView controls in all projects. You can enable this feature in the GridView control, for example, by setting the EnablePersistedSelection property, as shown in the following example: <asp:GridView id="GridView2" runat="server" PersistedSelection="true"> </asp:GridView> FormView Control Enhancements The FormView control is enhanced to make it easier to style the content of the control with CSS. In previous versions of ASP.NET, the FormView control rendered it contents using an item template. This made styling more difficult in the markup because unexpected table row and table cell tags were rendered by the control. The FormView control supports RenderOuterTable, a property in ASP.NET 4. When this property is set to false, as show in the following example, the table tags are not rendered. This makes it easier to apply CSS style to the contents of the control. <asp:FormView ID="FormView1" runat="server" RenderTable="false"> For more information, see FormView Web Server Control Overview. ListView Control Enhancements The ListView control, which was introduced in ASP.NET 3.5, has all the functionality of the GridView control while giving you complete control over the output. This control has been made easier to use in ASP.NET 4. The earlier version of the control required that you specify a layout template that contained a server control with a known ID. The following markup shows a typical example of how to use the ListView control in ASP.NET 3.5. <asp:ListView ID="ListView1" runat="server"> <LayoutTemplate> <asp:PlaceHolder ID="ItemPlaceHolder" runat="server"></asp:PlaceHolder> </LayoutTemplate> <ItemTemplate> <% Eval("LastName")%> </ItemTemplate> </asp:ListView> In ASP.NET 4, the ListView control does not require a layout template. The markup shown in the previous example can be replaced with the following markup: <asp:ListView ID="ListView1" runat="server"> <ItemTemplate> <% Eval("LastName")%> </ItemTemplate> </asp:ListView> For more information, see ListView Web Server Control Overview. Filtering Data with the QueryExtender Control A very common task for developers who create data-driven Web pages is to filter data. This traditionally has been performed by building Where clauses in data source controls. This approach can be complicated, and in some cases the Where syntax does not let you take advantage of the full functionality of the underlying database. To make filtering easier, a new QueryExtender control has been added in ASP.NET 4. This control can be added to EntityDataSource or LinqDataSource controls in order to filter the data returned by these controls. Because the QueryExtender control relies on LINQ, but you do not to need to know how to write LINQ queries to use the query extender. The QueryExtender control supports a variety of filter options. The following lists QueryExtender filter options. Term Definition SearchExpression Searches a field or fields for string values and compares them to a specified string value. RangeExpression Searches a field or fields for values in a range specified by a pair of values. PropertyExpression Compares a specified value to a property value in a field. If the expression evaluates to true, the data that is being examined is returned. OrderByExpression Sorts data by a specified column and sort direction. CustomExpression Calls a function that defines custom filter in the page. For more information, see QueryExtenderQueryExtender Web Server Control Overview. Enhanced Support for Web Standards and Accessibility Earlier versions of ASP.NET controls sometimes render markup that does not conform to HTML, XHTML, or accessibility standards. ASP.NET 4 eliminates most of these exceptions. For details about how the HTML that is rendered by each control meets accessibility standards, see ASP.NET Controls and Accessibility. CSS for Controls that Can be Disabled In ASP.NET 3.5, when a control is disabled (see WebControl.Enabled), a disabled attribute is added to the rendered HTML element. For example, the following markup creates a Label control that is disabled: <asp:Label id="Label1" runat="server"   Text="Test" Enabled="false" /> In ASP.NET 3.5, the previous control settings generate the following HTML: <span id="Label1" disabled="disabled">Test</span> In HTML 4.01, the disabled attribute is not considered valid on span elements. It is valid only on input elements because it specifies that they cannot be accessed. On display-only elements such as span elements, browsers typically support rendering for a disabled appearance, but a Web page that relies on this non-standard behavior is not robust according to accessibility standards. For display-only elements, you should use CSS to indicate a disabled visual appearance. Therefore, by default ASP.NET 4 generates the following HTML for the control settings shown previously: <span id="Label1" class="aspNetDisabled">Test</span> You can change the value of the class attribute that is rendered by default when a control is disabled by setting the DisabledCssClass property. CSS for Validation Controls In ASP.NET 3.5, validation controls render a default color of red as an inline style. For example, the following markup creates a RequiredFieldValidator control: <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server"   ErrorMessage="Required Field" ControlToValidate="RadioButtonList1" /> ASP.NET 3.5 renders the following HTML for the validator control: <span id="RequiredFieldValidator1"   style="color:Red;visibility:hidden;">RequiredFieldValidator</span> By default, ASP.NET 4 does not render an inline style to set the color to red. An inline style is used only to hide or show the validator, as shown in the following example: <span id="RequiredFieldValidator1"   style"visibility:hidden;">RequiredFieldValidator</span> Therefore, ASP.NET 4 does not automatically show error messages in red. For information about how to use CSS to specify a visual style for a validation control, see Validating User Input in ASP.NET Web Pages. CSS for the Hidden Fields Div Element ASP.NET uses hidden fields to store state information such as view state and control state. These hidden fields are contained by a div element. In ASP.NET 3.5, this div element does not have a class attribute or an id attribute. Therefore, CSS rules that affect all div elements could unintentionally cause this div to be visible. To avoid this problem, ASP.NET 4 renders the div element for hidden fields with a CSS class that you can use to differentiate the hidden fields div from others. The new classvalue is shown in the following example: <div class="aspNetHidden"> CSS for the Table, Image, and ImageButton Controls By default, in ASP.NET 3.5, some controls set the border attribute of rendered HTML to zero (0). The following example shows HTML that is generated by the Table control in ASP.NET 3.5: <table id="Table2" border="0"> The Image control and the ImageButton control also do this. Because this is not necessary and provides visual formatting information that should be provided by using CSS, the attribute is not generated in ASP.NET 4. CSS for the UpdatePanel and UpdateProgress Controls In ASP.NET 3.5, the UpdatePanel and UpdateProgress controls do not support expando attributes. This makes it impossible to set a CSS class on the HTMLelements that they render. In ASP.NET 4 these controls have been changed to accept expando attributes, as shown in the following example: <asp:UpdatePanel runat="server" class="myStyle"> </asp:UpdatePanel> The following HTML is rendered for this markup: <div id="ctl00_MainContent_UpdatePanel1" class="expandoclass"> </div> Eliminating Unnecessary Outer Tables In ASP.NET 3.5, the HTML that is rendered for the following controls is wrapped in a table element whose purpose is to apply inline styles to the entire control: FormView Login PasswordRecovery ChangePassword If you use templates to customize the appearance of these controls, you can specify CSS styles in the markup that you provide in the templates. In that case, no extra outer table is required. In ASP.NET 4, you can prevent the table from being rendered by setting the new RenderOuterTable property to false. Layout Templates for Wizard Controls In ASP.NET 3.5, the Wizard and CreateUserWizard controls generate an HTML table element that is used for visual formatting. In ASP.NET 4 you can use a LayoutTemplate element to specify the layout. If you do this, the HTML table element is not generated. In the template, you create placeholder controls to indicate where items should be dynamically inserted into the control. (This is similar to how the template model for the ListView control works.) For more information, see the Wizard.LayoutTemplate property. New HTML Formatting Options for the CheckBoxList and RadioButtonList Controls ASP.NET 3.5 uses HTML table elements to format the output for the CheckBoxList and RadioButtonList controls. To provide an alternative that does not use tables for visual formatting, ASP.NET 4 adds two new options to the RepeatLayout enumeration: UnorderedList. This option causes the HTML output to be formatted by using ul and li elements instead of a table. OrderedList. This option causes the HTML output to be formatted by using ol and li elements instead of a table. For examples of HTML that is rendered for the new options, see the RepeatLayout enumeration. Header and Footer Elements for the Table Control In ASP.NET 3.5, the Table control can be configured to render thead and tfoot elements by setting the TableSection property of the TableHeaderRow class and the TableFooterRow class. In ASP.NET 4 these properties are set to the appropriate values by default. CSS and ARIA Support for the Menu Control In ASP.NET 3.5, the Menu control uses HTML table elements for visual formatting, and in some configurations it is not keyboard-accessible. ASP.NET 4 addresses these problems and improves accessibility in the following ways: The generated HTML is structured as an unordered list (ul and li elements). CSS is used for visual formatting. The menu behaves in accordance with ARIA standards for keyboard access. You can use arrow keys to navigate menu items. (For information about ARIA, see Accessibility in Visual Studio and ASP.NET.) ARIA role and property attributes are added to the generated HTML. (Attributes are added by using JavaScript instead of included in the HTML, to avoid generating HTML that would cause markup validation errors.) Styles for the Menu control are rendered in a style block at the top of the page, instead of inline with the rendered HTML elements. If you want to use a separate CSS file so that you can modify the menu styles, you can set the Menu control's new IncludeStyleBlock property to false, in which case the style block is not generated. Valid XHTML for the HtmlForm Control In ASP.NET 3.5, the HtmlForm control (which is created implicitly by the <form runat="server"> tag) renders an HTML form element that has both name and id attributes. The name attribute is deprecated in XHTML 1.1. Therefore, this control does not render the name attribute in ASP.NET 4. Maintaining Backward Compatibility in Control Rendering An existing ASP.NET Web site might have code in it that assumes that controls are rendering HTML the way they do in ASP.NET 3.5. To avoid causing backward compatibility problems when you upgrade the site to ASP.NET 4, you can have ASP.NET continue to generate HTML the way it does in ASP.NET 3.5 after you upgrade the site. To do so, you can set the controlRenderingCompatibilityVersion attribute of the pages element to "3.5" in the Web.config file of an ASP.NET 4 Web site, as shown in the following example: <system.web>   <pages controlRenderingCompatibilityVersion="3.5"/> </system.web> If this setting is omitted, the default value is the same as the version of ASP.NET that the Web site targets. (For information about multi-targeting in ASP.NET, see .NET Framework Multi-Targeting for ASP.NET Web Projects.) ASP.NET MVC ASP.NET MVC helps Web developers build compelling standards-based Web sites that are easy to maintain because it decreases the dependency among application layers by using the Model-View-Controller (MVC) pattern. MVC provides complete control over the page markup. It also improves testability by inherently supporting Test Driven Development (TDD). Web sites created using ASP.NET MVC have a modular architecture. This allows members of a team to work independently on the various modules and can be used to improve collaboration. For example, developers can work on the model and controller layers (data and logic), while the designer work on the view (presentation). For tutorials, walkthroughs, conceptual content, code samples, and a complete API reference, see ASP.NET MVC 2. Dynamic Data Dynamic Data was introduced in the .NET Framework 3.5 SP1 release in mid-2008. This feature provides many enhancements for creating data-driven applications, such as the following: A RAD experience for quickly building a data-driven Web site. Automatic validation that is based on constraints defined in the data model. The ability to easily change the markup that is generated for fields in the GridView and DetailsView controls by using field templates that are part of your Dynamic Data project. For ASP.NET 4, Dynamic Data has been enhanced to give developers even more power for quickly building data-driven Web sites. For more information, see ASP.NET Dynamic Data Content Map. Enabling Dynamic Data for Individual Data-Bound Controls in Existing Web Applications You can use Dynamic Data features in existing ASP.NET Web applications that do not use scaffolding by enabling Dynamic Data for individual data-bound controls. Dynamic Data provides the presentation and data layer support for rendering these controls. When you enable Dynamic Data for data-bound controls, you get the following benefits: Setting default values for data fields. Dynamic Data enables you to provide default values at run time for fields in a data control. Interacting with the database without creating and registering a data model. Automatically validating the data that is entered by the user without writing any code. For more information, see Walkthrough: Enabling Dynamic Data in ASP.NET Data-Bound Controls. New Field Templates for URLs and E-mail Addresses ASP.NET 4 introduces two new built-in field templates, EmailAddress.ascx and Url.ascx. These templates are used for fields that are marked as EmailAddress or Url using the DataTypeAttribute attribute. For EmailAddress objects, the field is displayed as a hyperlink that is created by using the mailto: protocol. When users click the link, it opens the user's e-mail client and creates a skeleton message. Objects typed as Url are displayed as ordinary hyperlinks. The following example shows how to mark fields. [DataType(DataType.EmailAddress)] public object HomeEmail { get; set; } [DataType(DataType.Url)] public object Website { get; set; } Creating Links with the DynamicHyperLink Control Dynamic Data uses the new routing feature that was added in the .NET Framework 3.5 SP1 to control the URLs that users see when they access the Web site. The new DynamicHyperLink control makes it easy to build links to pages in a Dynamic Data site. For information, see How to: Create Table Action Links in Dynamic Data Support for Inheritance in the Data Model Both the ADO.NET Entity Framework and LINQ to SQL support inheritance in their data models. An example of this might be a database that has an InsurancePolicy table. It might also contain CarPolicy and HousePolicy tables that have the same fields as InsurancePolicy and then add more fields. Dynamic Data has been modified to understand inherited objects in the data model and to support scaffolding for the inherited tables. For more information, see Walkthrough: Mapping Table-per-Hierarchy Inheritance in Dynamic Data. Support for Many-to-Many Relationships (Entity Framework Only) The Entity Framework has rich support for many-to-many relationships between tables, which is implemented by exposing the relationship as a collection on an Entity object. New field templates (ManyToMany.ascx and ManyToMany_Edit.ascx) have been added to provide support for displaying and editing data that is involved in many-to-many relationships. For more information, see Working with Many-to-Many Data Relationships in Dynamic Data. New Attributes to Control Display and Support Enumerations The DisplayAttribute has been added to give you additional control over how fields are displayed. The DisplayNameAttribute attribute in earlier versions of Dynamic Data enabled you to change the name that is used as a caption for a field. The new DisplayAttribute class lets you specify more options for displaying a field, such as the order in which a field is displayed and whether a field will be used as a filter. The attribute also provides independent control of the name that is used for the labels in a GridView control, the name that is used in a DetailsView control, the help text for the field, and the watermark used for the field (if the field accepts text input). The EnumDataTypeAttribute class has been added to let you map fields to enumerations. When you apply this attribute to a field, you specify an enumeration type. Dynamic Data uses the new Enumeration.ascx field template to create UI for displaying and editing enumeration values. The template maps the values from the database to the names in the enumeration. Enhanced Support for Filters Dynamic Data 1.0 had built-in filters for Boolean columns and foreign-key columns. The filters did not let you specify the order in which they were displayed. The new DisplayAttribute attribute addresses this by giving you control over whether a column appears as a filter and in what order it will be displayed. An additional enhancement is that filtering support has been rewritten to use the new QueryExtender feature of Web Forms. This lets you create filters without requiring knowledge of the data source control that the filters will be used with. Along with these extensions, filters have also been turned into template controls, which lets you add new ones. Finally, the DisplayAttribute class mentioned earlier allows the default filter to be overridden, in the same way that UIHint allows the default field template for a column to be overridden. For more information, see Walkthrough: Filtering Rows in Tables That Have a Parent-Child Relationship and QueryableFilterRepeater. ASP.NET Chart Control The ASP.NET chart server control enables you to create ASP.NET pages applications that have simple, intuitive charts for complex statistical or financial analysis. The chart control supports the following features: Data series, chart areas, axes, legends, labels, titles, and more. Data binding. Data manipulation, such as copying, splitting, merging, alignment, grouping, sorting, searching, and filtering. Statistical formulas and financial formulas. Advanced chart appearance, such as 3-D, anti-aliasing, lighting, and perspective. Events and customizations. Interactivity and Microsoft Ajax. Support for the Ajax Content Delivery Network (CDN), which provides an optimized way for you to add Microsoft Ajax Library and jQuery scripts to your Web applications. For more information, see Chart Web Server Control Overview. Visual Web Developer Enhancements The following sections provide information about enhancements and new features in Visual Studio 2010 and Visual Web Developer Express. The Web page designer in Visual Studio 2010 has been enhanced for better CSS compatibility, includes additional support for HTML and ASP.NET markup snippets, and features a redesigned version of IntelliSense for JScript. Improved CSS Compatibility The Visual Web Developer designer in Visual Studio 2010 has been updated to improve CSS 2.1 standards compliance. The designer better preserves HTML source code and is more robust than in previous versions of Visual Studio. HTML and JScript Snippets In the HTML editor, IntelliSense auto-completes tag names. The IntelliSense Snippets feature auto-completes whole tags and more. In Visual Studio 2010, IntelliSense snippets are supported for JScript, alongside C# and Visual Basic, which were supported in earlier versions of Visual Studio. Visual Studio 2010 includes over 200 snippets that help you auto-complete common ASP.NET and HTML tags, including required attributes (such as runat="server") and common attributes specific to a tag (such as ID, DataSourceID, ControlToValidate, and Text). You can download additional snippets, or you can write your own snippets that encapsulate the blocks of markup that you or your team use for common tasks. For more information on HTML snippets, see Walkthrough: Using HTML Snippets. JScript IntelliSense Enhancements In Visual 2010, JScript IntelliSense has been redesigned to provide an even richer editing experience. IntelliSense now recognizes objects that have been dynamically generated by methods such as registerNamespace and by similar techniques used by other JavaScript frameworks. Performance has been improved to analyze large libraries of script and to display IntelliSense with little or no processing delay. Compatibility has been significantly increased to support almost all third-party libraries and to support diverse coding styles. Documentation comments are now parsed as you type and are immediately leveraged by IntelliSense. Web Application Deployment with Visual Studio 2010 For Web application projects, Visual Studio now provides tools that work with the IIS Web Deployment Tool (Web Deploy) to automate many processes that had to be done manually in earlier versions of ASP.NET. For example, the following tasks can now be automated: Creating an IIS application on the destination computer and configuring IIS settings. Copying files to the destination computer. Changing Web.config settings that must be different in the destination environment. Propagating changes to data or data structures in SQL Server databases that are used by the Web application. For more information about Web application deployment, see ASP.NET Deployment Content Map. Enhancements to ASP.NET Multi-Targeting ASP.NET 4 adds new features to the multi-targeting feature to make it easier to work with projects that target earlier versions of the .NET Framework. Multi-targeting was introduced in ASP.NET 3.5 to enable you to use the latest version of Visual Studio without having to upgrade existing Web sites or Web services to the latest version of the .NET Framework. In Visual Studio 2008, when you work with a project targeted for an earlier version of the .NET Framework, most features of the development environment adapt to the targeted version. However, IntelliSense displays language features that are available in the current version, and property windows display properties available in the current version. In Visual Studio 2010, only language features and properties available in the targeted version of the .NET Framework are shown. For more information about multi-targeting, see the following topics: .NET Framework Multi-Targeting for ASP.NET Web Projects ASP.NET Side-by-Side Execution Overview How to: Host Web Applications That Use Different Versions of the .NET Framework on the Same Server How to: Deploy Web Site Projects Targeted for Earlier Versions of the .NET Framework

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• Using the West Wind Web Toolkit to set up AJAX and REST Services

  - by Rick Strahl

  I frequently get questions about which option to use for creating AJAX and REST backends for ASP.NET applications. There are many solutions out there to do this actually, but when I have a choice - not surprisingly - I fall back to my own tools in the West Wind West Wind Web Toolkit. I've talked a bunch about the 'in-the-box' solutions in the past so for a change in this post I'll talk about the tools that I use in my own and customer applications to handle AJAX and REST based access to service resources using the West Wind West Wind Web Toolkit. Let me preface this by saying that I like things to be easy. Yes flexible is very important as well but not at the expense of over-complexity. The goal I've had with my tools is make it drop dead easy, with good performance while providing the core features that I'm after, which are: Easy AJAX/JSON Callbacks Ability to return any kind of non JSON content (string, stream, byte[], images) Ability to work with both XML and JSON interchangeably for input/output Access endpoints via POST data, RPC JSON calls, GET QueryString values or Routing interface Easy to use generic JavaScript client to make RPC calls (same syntax, just what you need) Ability to create clean URLS with Routing Ability to use standard ASP.NET HTTP Stack for HTTP semantics It's all about options! In this post I'll demonstrate most of these features (except XML) in a few simple and short samples which you can download. So let's take a look and see how you can build an AJAX callback solution with the West Wind Web Toolkit. Installing the Toolkit Assemblies The easiest and leanest way of using the Toolkit in your Web project is to grab it via NuGet: West Wind Web and AJAX Utilities (Westwind.Web) and drop it into the project by right clicking in your Project and choosing Manage NuGet Packages from anywhere in the Project.   When done you end up with your project looking like this: What just happened? Nuget added two assemblies - Westwind.Web and Westwind.Utilities and the client ww.jquery.js library. It also added a couple of references into web.config: The default namespaces so they can be accessed in pages/views and a ScriptCompressionModule that the toolkit optionally uses to compress script resources served from within the assembly (namely ww.jquery.js and optionally jquery.js). Creating a new Service The West Wind Web Toolkit supports several ways of creating and accessing AJAX services, but for this post I'll stick to the lower level approach that works from any plain HTML page or of course MVC, WebForms, WebPages. There's also a WebForms specific control that makes this even easier but I'll leave that for another post. So, to create a new standalone AJAX/REST service we can create a new HttpHandler in the new project either as a pure class based handler or as a generic .ASHX handler. Both work equally well, but generic handlers don't require any web.config configuration so I'll use that here. In the root of the project add a Generic Handler. I'm going to call this one StockService.ashx. Once the handler has been created, edit the code and remove all of the handler body code. Then change the base class to CallbackHandler and add methods that have a [CallbackMethod] attribute. Here's the modified base handler implementation now looks like with an added HelloWorld method: using System; using Westwind.Web; namespace WestWindWebAjax { /// <summary> /// Handler implements CallbackHandler to provide REST/AJAX services /// </summary> public class SampleService : CallbackHandler { [CallbackMethod] public string HelloWorld(string name) { return "Hello " + name + ". Time is: " + DateTime.Now.ToString(); } } } Notice that the class inherits from CallbackHandler and that the HelloWorld service method is marked up with [CallbackMethod]. We're done here. Services Urlbased Syntax Once you compile, the 'service' is live can respond to requests. All CallbackHandlers support input in GET and POST formats, and can return results as JSON or XML. To check our fancy HelloWorld method we can now access the service like this: http://localhost/WestWindWebAjax/StockService.ashx?Method=HelloWorld&name=Rick which produces a default JSON response - in this case a string (wrapped in quotes as it's JSON): (note by default JSON will be downloaded by most browsers not displayed - various options are available to view JSON right in the browser) If I want to return the same data as XML I can tack on a &format=xml at the end of the querystring which produces: <string>Hello Rick. Time is: 11/1/2011 12:11:13 PM</string> Cleaner URLs with Routing Syntax If you want cleaner URLs for each operation you can also configure custom routes on a per URL basis similar to the way that WCF REST does. To do this you need to add a new RouteHandler to your application's startup code in global.asax.cs one for each CallbackHandler based service you create: protected void Application_Start(object sender, EventArgs e) { CallbackHandlerRouteHandler.RegisterRoutes<StockService>(RouteTable.Routes); } With this code in place you can now add RouteUrl properties to any of your service methods. For the HelloWorld method that doesn't make a ton of sense but here is what a routed clean URL might look like in definition: [CallbackMethod(RouteUrl="stocks/HelloWorld/{name}")] public string HelloWorld(string name) { return "Hello " + name + ". Time is: " + DateTime.Now.ToString(); } The same URL I previously used now becomes a bit shorter and more readable with: http://localhost/WestWindWebAjax/HelloWorld/Rick It's an easy way to create cleaner URLs and still get the same functionality. Calling the Service with $.getJSON() Since the result produced is JSON you can now easily consume this data using jQuery's getJSON method. First we need a couple of scripts - jquery.js and ww.jquery.js in the page: <!DOCTYPE html> <html> <head> <link href="Css/Westwind.css" rel="stylesheet" type="text/css" /> <script src="scripts/jquery.min.js" type="text/javascript"></script> <script src="scripts/ww.jquery.min.js" type="text/javascript"></script> </head> <body> Next let's add a small HelloWorld example form (what else) that has a single textbox to type a name, a button and a div tag to receive the result: <fieldset> <legend>Hello World</legend> Please enter a name: <input type="text" name="txtHello" id="txtHello" value="" /> <input type="button" id="btnSayHello" value="Say Hello (POST)" /> <input type="button" id="btnSayHelloGet" value="Say Hello (GET)" /> <div id="divHelloMessage" class="errordisplay" style="display:none;width: 450px;" > </div> </fieldset> Then to call the HelloWorld method a little jQuery is used to hook the document startup and the button click followed by the $.getJSON call to retrieve the data from the server. <script type="text/javascript"> $(document).ready(function () { $("#btnSayHelloGet").click(function () { $.getJSON("SampleService.ashx", { Method: "HelloWorld", name: $("#txtHello").val() }, function (result) { $("#divHelloMessage") .text(result) .fadeIn(1000); }); });</script> .getJSON() expects a full URL to the endpoint of our service, which is the ASHX file. We can either provide a full URL (SampleService.ashx?Method=HelloWorld&name=Rick) or we can just provide the base URL and an object that encodes the query string parameters for us using an object map that has a property that matches each parameter for the server method. We can also use the clean URL routing syntax, but using the object parameter encoding actually is safer as the parameters will get properly encoded by jQuery. The result returned is whatever the result on the server method is - in this case a string. The string is applied to the divHelloMessage element and we're done. Obviously this is a trivial example, but it demonstrates the basics of getting a JSON response back to the browser. AJAX Post Syntax - using ajaxCallMethod() The previous example allows you basic control over the data that you send to the server via querystring parameters. This works OK for simple values like short strings, numbers and boolean values, but doesn't really work if you need to pass something more complex like an object or an array back up to the server. To handle traditional RPC type messaging where the idea is to map server side functions and results to a client side invokation, POST operations can be used. The easiest way to use this functionality is to use ww.jquery.js and the ajaxCallMethod() function. ww.jquery wraps jQuery's AJAX functions and knows implicitly how to call a CallbackServer method with parameters and parse the result. Let's look at another simple example that posts a simple value but returns something more interesting. Let's start with the service method: [CallbackMethod(RouteUrl="stocks/{symbol}")] public StockQuote GetStockQuote(string symbol) { Response.Cache.SetExpires(DateTime.UtcNow.Add(new TimeSpan(0, 2, 0))); StockServer server = new StockServer(); var quote = server.GetStockQuote(symbol); if (quote == null) throw new ApplicationException("Invalid Symbol passed."); return quote; } This sample utilizes a small StockServer helper class (included in the sample) that downloads a stock quote from Yahoo's financial site via plain HTTP GET requests and formats it into a StockQuote object. Lets create a small HTML block that lets us query for the quote and display it: <fieldset> <legend>Single Stock Quote</legend> Please enter a stock symbol: <input type="text" name="txtSymbol" id="txtSymbol" value="msft" /> <input type="button" id="btnStockQuote" value="Get Quote" /> <div id="divStockDisplay" class="errordisplay" style="display:none; width: 450px;"> <div class="label-left">Company:</div> <div id="stockCompany"></div> <div class="label-left">Last Price:</div> <div id="stockLastPrice"></div> <div class="label-left">Quote Time:</div> <div id="stockQuoteTime"></div> </div> </fieldset> The final result looks something like this:   Let's hook up the button handler to fire the request and fill in the data as shown: $("#btnStockQuote").click(function () { ajaxCallMethod("SampleService.ashx", "GetStockQuote", [$("#txtSymbol").val()], function (quote) { $("#divStockDisplay").show().fadeIn(1000); $("#stockCompany").text(quote.Company + " (" + quote.Symbol + ")"); $("#stockLastPrice").text(quote.LastPrice); $("#stockQuoteTime").text(quote.LastQuoteTime.formatDate("MMM dd, HH:mm EST")); }, onPageError); }); So we point at SampleService.ashx and the GetStockQuote method, passing a single parameter of the input symbol value. Then there are two handlers for success and failure callbacks.  The success handler is the interesting part - it receives the stock quote as a result and assigns its values to various 'holes' in the stock display elements. The data that comes back over the wire is JSON and it looks like this: { "Symbol":"MSFT", "Company":"Microsoft Corpora", "OpenPrice":26.11, "LastPrice":26.01, "NetChange":0.02, "LastQuoteTime":"2011-11-03T02:00:00Z", "LastQuoteTimeString":"Nov. 11, 2011 4:20pm" } which is an object representation of the data. JavaScript can evaluate this JSON string back into an object easily and that's the reslut that gets passed to the success function. The quote data is then applied to existing page content by manually selecting items and applying them. There are other ways to do this more elegantly like using templates, but here we're only interested in seeing how the data is returned. The data in the object is typed - LastPrice is a number and QuoteTime is a date. Note about the date value: JavaScript doesn't have a date literal although the JSON embedded ISO string format used above  ("2011-11-03T02:00:00Z") is becoming fairly standard for JSON serializers. However, JSON parsers don't deserialize dates by default and return them by string. This is why the StockQuote actually returns a string value of LastQuoteTimeString for the same date. ajaxMethodCallback always converts dates properly into 'real' dates and the example above uses the real date value along with a .formatDate() data extension (also in ww.jquery.js) to display the raw date properly. Errors and Exceptions So what happens if your code fails? For example if I pass an invalid stock symbol to the GetStockQuote() method you notice that the code does this: if (quote == null) throw new ApplicationException("Invalid Symbol passed."); CallbackHandler automatically pushes the exception message back to the client so it's easy to pick up the error message. Regardless of what kind of error occurs: Server side, client side, protocol errors - any error will fire the failure handler with an error object parameter. The error is returned to the client via a JSON response in the error callback. In the previous examples I called onPageError which is a generic routine in ww.jquery that displays a status message on the bottom of the screen. But of course you can also take over the error handling yourself: $("#btnStockQuote").click(function () { ajaxCallMethod("SampleService.ashx", "GetStockQuote", [$("#txtSymbol").val()], function (quote) { $("#divStockDisplay").fadeIn(1000); $("#stockCompany").text(quote.Company + " (" + quote.Symbol + ")"); $("#stockLastPrice").text(quote.LastPrice); $("#stockQuoteTime").text(quote.LastQuoteTime.formatDate("MMM dd, hh:mmt")); }, function (error, xhr) { $("#divErrorDisplay").text(error.message).fadeIn(1000); }); }); The error object has a isCallbackError, message and  stackTrace properties, the latter of which is only populated when running in Debug mode, and this object is returned for all errors: Client side, transport and server side errors. Regardless of which type of error you get the same object passed (as well as the XHR instance optionally) which makes for a consistent error retrieval mechanism. Specifying HttpVerbs You can also specify HTTP Verbs that are allowed using the AllowedHttpVerbs option on the CallbackMethod attribute: [CallbackMethod(AllowedHttpVerbs=HttpVerbs.GET | HttpVerbs.POST)] public string HelloWorld(string name) { … } If you're building REST style API's this might be useful to force certain request semantics onto the client calling. For the above if call with a non-allowed HttpVerb the request returns a 405 error response along with a JSON (or XML) error object result. The default behavior is to allow all verbs access (HttpVerbs.All). Passing in object Parameters Up to now the parameters I passed were very simple. But what if you need to send something more complex like an object or an array? Let's look at another example now that passes an object from the client to the server. Keeping with the Stock theme here lets add a method called BuyOrder that lets us buy some shares for a stock. Consider the following service method that receives an StockBuyOrder object as a parameter: [CallbackMethod] public string BuyStock(StockBuyOrder buyOrder) { var server = new StockServer(); var quote = server.GetStockQuote(buyOrder.Symbol); if (quote == null) throw new ApplicationException("Invalid or missing stock symbol."); return string.Format("You're buying {0} shares of {1} ({2}) stock at {3} for a total of {4} on {5}.", buyOrder.Quantity, quote.Company, quote.Symbol, quote.LastPrice.ToString("c"), (quote.LastPrice * buyOrder.Quantity).ToString("c"), buyOrder.BuyOn.ToString("MMM d")); } public class StockBuyOrder { public string Symbol { get; set; } public int Quantity { get; set; } public DateTime BuyOn { get; set; } public StockBuyOrder() { BuyOn = DateTime.Now; } } This is a contrived do-nothing example that simply echoes back what was passed in, but it demonstrates how you can pass complex data to a callback method. On the client side we now have a very simple form that captures the three values on a form: <fieldset> <legend>Post a Stock Buy Order</legend> Enter a symbol: <input type="text" name="txtBuySymbol" id="txtBuySymbol" value="GLD" />&nbsp;&nbsp; Qty: <input type="text" name="txtBuyQty" id="txtBuyQty" value="10" style="width: 50px" />&nbsp;&nbsp; Buy on: <input type="text" name="txtBuyOn" id="txtBuyOn" value="<%= DateTime.Now.ToString("d") %>" style="width: 70px;" /> <input type="button" id="btnBuyStock" value="Buy Stock" /> <div id="divStockBuyMessage" class="errordisplay" style="display:none"></div> </fieldset> The completed form and demo then looks something like this:   The client side code that picks up the input values and assigns them to object properties and sends the AJAX request looks like this: $("#btnBuyStock").click(function () { // create an object map that matches StockBuyOrder signature var buyOrder = { Symbol: $("#txtBuySymbol").val(), Quantity: $("#txtBuyQty").val() * 1, // number Entered: new Date() } ajaxCallMethod("SampleService.ashx", "BuyStock", [buyOrder], function (result) { $("#divStockBuyMessage").text(result).fadeIn(1000); }, onPageError); }); The code creates an object and attaches the properties that match the server side object passed to the BuyStock method. Each property that you want to update needs to be included and the type must match (ie. string, number, date in this case). Any missing properties will not be set but also not cause any errors. Pass POST data instead of Objects In the last example I collected a bunch of values from form variables and stuffed them into object variables in JavaScript code. While that works, often times this isn't really helping - I end up converting my types on the client and then doing another conversion on the server. If lots of input controls are on a page and you just want to pick up the values on the server via plain POST variables - that can be done too - and it makes sense especially if you're creating and filling the client side object only to push data to the server. Let's add another method to the server that once again lets us buy a stock. But this time let's not accept a parameter but rather send POST data to the server. Here's the server method receiving POST data: [CallbackMethod] public string BuyStockPost() { StockBuyOrder buyOrder = new StockBuyOrder(); buyOrder.Symbol = Request.Form["txtBuySymbol"]; ; int qty; int.TryParse(Request.Form["txtBuyQuantity"], out qty); buyOrder.Quantity = qty; DateTime time; DateTime.TryParse(Request.Form["txtBuyBuyOn"], out time); buyOrder.BuyOn = time; // Or easier way yet //FormVariableBinder.Unbind(buyOrder,null,"txtBuy"); var server = new StockServer(); var quote = server.GetStockQuote(buyOrder.Symbol); if (quote == null) throw new ApplicationException("Invalid or missing stock symbol."); return string.Format("You're buying {0} shares of {1} ({2}) stock at {3} for a total of {4} on {5}.", buyOrder.Quantity, quote.Company, quote.Symbol, quote.LastPrice.ToString("c"), (quote.LastPrice * buyOrder.Quantity).ToString("c"), buyOrder.BuyOn.ToString("MMM d")); } Clearly we've made this server method take more code than it did with the object parameter. We've basically moved the parameter assignment logic from the client to the server. As a result the client code to call this method is now a bit shorter since there's no client side shuffling of values from the controls to an object. $("#btnBuyStockPost").click(function () { ajaxCallMethod("SampleService.ashx", "BuyStockPost", [], // Note: No parameters - function (result) { $("#divStockBuyMessage").text(result).fadeIn(1000); }, onPageError, // Force all page Form Variables to be posted { postbackMode: "Post" }); }); The client simply calls the BuyStockQuote method and pushes all the form variables from the page up to the server which parses them instead. The feature that makes this work is one of the options you can pass to the ajaxCallMethod() function: { postbackMode: "Post" }); which directs the function to include form variable POST data when making the service call. Other options include PostNoViewState (for WebForms to strip out WebForms crap vars), PostParametersOnly (default), None. If you pass parameters those are always posted to the server except when None is set. The above code can be simplified a bit by using the FormVariableBinder helper, which can unbind form variables directly into an object: FormVariableBinder.Unbind(buyOrder,null,"txtBuy"); which replaces the manual Request.Form[] reading code. It receives the object to unbind into, a string of properties to skip, and an optional prefix which is stripped off form variables to match property names. The component is similar to the MVC model binder but it's independent of MVC. Returning non-JSON Data CallbackHandler also supports returning non-JSON/XML data via special return types. You can return raw non-JSON encoded strings like this: [CallbackMethod(ReturnAsRawString=true,ContentType="text/plain")] public string HelloWorldNoJSON(string name) { return "Hello " + name + ". Time is: " + DateTime.Now.ToString(); } Calling this method results in just a plain string - no JSON encoding with quotes around the result. This can be useful if your server handling code needs to return a string or HTML result that doesn't fit well for a page or other UI component. Any string output can be returned. You can also return binary data. Stream, byte[] and Bitmap/Image results are automatically streamed back to the client. Notice that you should set the ContentType of the request either on the CallbackMethod attribute or using Response.ContentType. This ensures the Web Server knows how to display your binary response. Using a stream response makes it possible to return any of data. Streamed data can be pretty handy to return bitmap data from a method. The following is a method that returns a stock history graph for a particular stock over a provided number of years: [CallbackMethod(ContentType="image/png",RouteUrl="stocks/history/graph/{symbol}/{years}")] public Stream GetStockHistoryGraph(string symbol, int years = 2,int width = 500, int height=350) { if (width == 0) width = 500; if (height == 0) height = 350; StockServer server = new StockServer(); return server.GetStockHistoryGraph(symbol,"Stock History for " + symbol,width,height,years); } I can now hook this up into the JavaScript code when I get a stock quote. At the end of the process I can assign the URL to the service that returns the image into the src property and so force the image to display. Here's the changed code: $("#btnStockQuote").click(function () { var symbol = $("#txtSymbol").val(); ajaxCallMethod("SampleService.ashx", "GetStockQuote", [symbol], function (quote) { $("#divStockDisplay").fadeIn(1000); $("#stockCompany").text(quote.Company + " (" + quote.Symbol + ")"); $("#stockLastPrice").text(quote.LastPrice); $("#stockQuoteTime").text(quote.LastQuoteTime.formatDate("MMM dd, hh:mmt")); // display a stock chart $("#imgStockHistory").attr("src", "stocks/history/graph/" + symbol + "/2"); },onPageError); }); The resulting output then looks like this: The charting code uses the new ASP.NET 4.0 Chart components via code to display a bar chart of the 2 year stock data as part of the StockServer class which you can find in the sample download. The ability to return arbitrary data from a service is useful as you can see - in this case the chart is clearly associated with the service and it's nice that the graph generation can happen off a handler rather than through a page. Images are common resources, but output can also be PDF reports, zip files for downloads etc. which is becoming increasingly more common to be returned from REST endpoints and other applications. Why reinvent? Obviously the examples I've shown here are pretty basic in terms of functionality. But I hope they demonstrate the core features of AJAX callbacks that you need to work through in most applications which is simple: return data, send back data and potentially retrieve data in various formats. While there are other solutions when it comes down to making AJAX callbacks and servicing REST like requests, I like the flexibility my home grown solution provides. Simply put it's still the easiest solution that I've found that addresses my common use cases: AJAX JSON RPC style callbacks Url based access XML and JSON Output from single method endpoint XML and JSON POST support, querystring input, routing parameter mapping UrlEncoded POST data support on callbacks Ability to return stream/raw string data Essentially ability to return ANYTHING from Service and pass anything All these features are available in various solutions but not together in one place. I've been using this code base for over 4 years now in a number of projects both for myself and commercial work and it's served me extremely well. Besides the AJAX functionality CallbackHandler provides, it's also an easy way to create any kind of output endpoint I need to create. Need to create a few simple routines that spit back some data, but don't want to create a Page or View or full blown handler for it? Create a CallbackHandler and add a method or multiple methods and you have your generic endpoints.  It's a quick and easy way to add small code pieces that are pretty efficient as they're running through a pretty small handler implementation. I can have this up and running in a couple of minutes literally without any setup and returning just about any kind of data. Resources Download the Sample NuGet: Westwind Web and AJAX Utilities (Westwind.Web) ajaxCallMethod() Documentation Using the AjaxMethodCallback WebForms Control West Wind Web Toolkit Home Page West Wind Web Toolkit Source Code © Rick Strahl, West Wind Technologies, 2005-2011Posted in ASP.NET  jQuery  AJAX   Tweet (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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• Upload File to Windows Azure Blob in Chunks through ASP.NET MVC, JavaScript and HTML5

  - by Shaun

  Originally posted on: http://geekswithblogs.net/shaunxu/archive/2013/07/01/upload-file-to-windows-azure-blob-in-chunks-through-asp.net.aspxMany people are using Windows Azure Blob Storage to store their data in the cloud. Blob storage provides 99.9% availability with easy-to-use API through .NET SDK and HTTP REST. For example, we can store JavaScript files, images, documents in blob storage when we are building an ASP.NET web application on a Web Role in Windows Azure. Or we can store our VHD files in blob and mount it as a hard drive in our cloud service. If you are familiar with Windows Azure, you should know that there are two kinds of blob: page blob and block blob. The page blob is optimized for random read and write, which is very useful when you need to store VHD files. The block blob is optimized for sequential/chunk read and write, which has more common usage. Since we can upload block blob in blocks through BlockBlob.PutBlock, and them commit them as a whole blob with invoking the BlockBlob.PutBlockList, it is very powerful to upload large files, as we can upload blocks in parallel, and provide pause-resume feature. There are many documents, articles and blog posts described on how to upload a block blob. Most of them are focus on the server side, which means when you had received a big file, stream or binaries, how to upload them into blob storage in blocks through .NET SDK.  But the problem is, how can we upload these large files from client side, for example, a browser. This questioned to me when I was working with a Chinese customer to help them build a network disk production on top of azure. The end users upload their files from the web portal, and then the files will be stored in blob storage from the Web Role. My goal is to find the best way to transform the file from client (end user’s machine) to the server (Web Role) through browser. In this post I will demonstrate and describe what I had done, to upload large file in chunks with high speed, and save them as blocks into Windows Azure Blob Storage.   Traditional Upload, Works with Limitation The simplest way to implement this requirement is to create a web page with a form that contains a file input element and a submit button. 1: @using (Html.BeginForm("About", "Index", FormMethod.Post, new { enctype = "multipart/form-data" })) 2: { 3: <input type="file" name="file" /> 4: <input type="submit" value="upload" /> 5: } And then in the backend controller, we retrieve the whole content of this file and upload it in to the blob storage through .NET SDK. We can split the file in blocks and upload them in parallel and commit. The code had been well blogged in the community. 1: [HttpPost] 2: public ActionResult About(HttpPostedFileBase file) 3: { 4: var container = _client.GetContainerReference("test"); 5: container.CreateIfNotExists(); 6: var blob = container.GetBlockBlobReference(file.FileName); 7: var blockDataList = new Dictionary<string, byte[]>(); 8: using (var stream = file.InputStream) 9: { 10: var blockSizeInKB = 1024; 11: var offset = 0; 12: var index = 0; 13: while (offset < stream.Length) 14: { 15: var readLength = Math.Min(1024 * blockSizeInKB, (int)stream.Length - offset); 16: var blockData = new byte[readLength]; 17: offset += stream.Read(blockData, 0, readLength); 18: blockDataList.Add(Convert.ToBase64String(BitConverter.GetBytes(index)), blockData); 19:  20: index++; 21: } 22: } 23:  24: Parallel.ForEach(blockDataList, (bi) => 25: { 26: blob.PutBlock(bi.Key, new MemoryStream(bi.Value), null); 27: }); 28: blob.PutBlockList(blockDataList.Select(b => b.Key).ToArray()); 29:  30: return RedirectToAction("About"); 31: } This works perfect if we selected an image, a music or a small video to upload. But if I selected a large file, let’s say a 6GB HD-movie, after upload for about few minutes the page will be shown as below and the upload will be terminated. In ASP.NET there is a limitation of request length and the maximized request length is defined in the web.config file. It’s a number which less than about 4GB. So if we want to upload a really big file, we cannot simply implement in this way. Also, in Windows Azure, a cloud service network load balancer will terminate the connection if exceed the timeout period. From my test the timeout looks like 2 - 3 minutes. Hence, when we need to upload a large file we cannot just use the basic HTML elements. Besides the limitation mentioned above, the simple HTML file upload cannot provide rich upload experience such as chunk upload, pause and pause-resume. So we need to find a better way to upload large file from the client to the server.   Upload in Chunks through HTML5 and JavaScript In order to break those limitation mentioned above we will try to upload the large file in chunks. This takes some benefit to us such as - No request size limitation: Since we upload in chunks, we can define the request size for each chunks regardless how big the entire file is. - No timeout problem: The size of chunks are controlled by us, which means we should be able to make sure request for each chunk upload will not exceed the timeout period of both ASP.NET and Windows Azure load balancer. It was a big challenge to upload big file in chunks until we have HTML5. There are some new features and improvements introduced in HTML5 and we will use them to implement our solution.   In HTML5, the File interface had been improved with a new method called “slice”. It can be used to read part of the file by specifying the start byte index and the end byte index. For example if the entire file was 1024 bytes, file.slice(512, 768) will read the part of this file from the 512nd byte to 768th byte, and return a new object of interface called "Blob”, which you can treat as an array of bytes. In fact,  a Blob object represents a file-like object of immutable, raw data. The File interface is based on Blob, inheriting blob functionality and expanding it to support files on the user's system. For more information about the Blob please refer here. File and Blob is very useful to implement the chunk upload. We will use File interface to represent the file the user selected from the browser and then use File.slice to read the file in chunks in the size we wanted. For example, if we wanted to upload a 10MB file with 512KB chunks, then we can read it in 512KB blobs by using File.slice in a loop.   Assuming we have a web page as below. User can select a file, an input box to specify the block size in KB and a button to start upload. 1: <div> 2: <input type="file" id="upload_files" name="files[]" /><br /> 3: Block Size: <input type="number" id="block_size" value="512" name="block_size" />KB<br /> 4: <input type="button" id="upload_button_blob" name="upload" value="upload (blob)" /> 5: </div> Then we can have the JavaScript function to upload the file in chunks when user clicked the button. 1: <script type="text/javascript"> 1: 2: $(function () { 3: $("#upload_button_blob").click(function () { 4: }); 5: });</script> Firstly we need to ensure the client browser supports the interfaces we are going to use. Just try to invoke the File, Blob and FormData from the “window” object. If any of them is “undefined” the condition result will be “false” which means your browser doesn’t support these premium feature and it’s time for you to get your browser updated. FormData is another new feature we are going to use in the future. It could generate a temporary form for us. We will use this interface to create a form with chunk and associated metadata when invoked the service through ajax. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: if (window.File && window.Blob && window.FormData) { 4: alert("Your brwoser is awesome, let's rock!"); 5: } 6: else { 7: alert("Oh man plz update to a modern browser before try is cool stuff out."); 8: return; 9: } 10: }); Each browser supports these interfaces by their own implementation and currently the Blob, File and File.slice are supported by Chrome 21, FireFox 13, IE 10, Opera 12 and Safari 5.1 or higher. After that we worked on the files the user selected one by one since in HTML5, user can select multiple files in one file input box. 1: var files = $("#upload_files")[0].files; 2: for (var i = 0; i < files.length; i++) { 3: var file = files[i]; 4: var fileSize = file.size; 5: var fileName = file.name; 6: } Next, we calculated the start index and end index for each chunks based on the size the user specified from the browser. We put them into an array with the file name and the index, which will be used when we upload chunks into Windows Azure Blob Storage as blocks since we need to specify the target blob name and the block index. At the same time we will store the list of all indexes into another variant which will be used to commit blocks into blob in Azure Storage once all chunks had been uploaded successfully. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10:  11: // calculate the start and end byte index for each blocks(chunks) 12: // with the index, file name and index list for future using 13: var blockSizeInKB = $("#block_size").val(); 14: var blockSize = blockSizeInKB * 1024; 15: var blocks = []; 16: var offset = 0; 17: var index = 0; 18: var list = ""; 19: while (offset < fileSize) { 20: var start = offset; 21: var end = Math.min(offset + blockSize, fileSize); 22:  23: blocks.push({ 24: name: fileName, 25: index: index, 26: start: start, 27: end: end 28: }); 29: list += index + ","; 30:  31: offset = end; 32: index++; 33: } 34: } 35: }); Now we have all chunks’ information ready. The next step should be upload them one by one to the server side, and at the server side when received a chunk it will upload as a block into Blob Storage, and finally commit them with the index list through BlockBlobClient.PutBlockList. But since all these invokes are ajax calling, which means not synchronized call. So we need to introduce a new JavaScript library to help us coordinate the asynchronize operation, which named “async.js”. You can download this JavaScript library here, and you can find the document here. I will not explain this library too much in this post. We will put all procedures we want to execute as a function array, and pass into the proper function defined in async.js to let it help us to control the execution sequence, in series or in parallel. Hence we will define an array and put the function for chunk upload into this array. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4:  5: // start to upload each files in chunks 6: var files = $("#upload_files")[0].files; 7: for (var i = 0; i < files.length; i++) { 8: var file = files[i]; 9: var fileSize = file.size; 10: var fileName = file.name; 11: // calculate the start and end byte index for each blocks(chunks) 12: // with the index, file name and index list for future using 13: ... ... 14:  15: // define the function array and push all chunk upload operation into this array 16: blocks.forEach(function (block) { 17: putBlocks.push(function (callback) { 18: }); 19: }); 20: } 21: }); 22: }); As you can see, I used File.slice method to read each chunks based on the start and end byte index we calculated previously, and constructed a temporary HTML form with the file name, chunk index and chunk data through another new feature in HTML5 named FormData. Then post this form to the backend server through jQuery.ajax. This is the key part of our solution. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10: // calculate the start and end byte index for each blocks(chunks) 11: // with the index, file name and index list for future using 12: ... ... 13: // define the function array and push all chunk upload operation into this array 14: blocks.forEach(function (block) { 15: putBlocks.push(function (callback) { 16: // load blob based on the start and end index for each chunks 17: var blob = file.slice(block.start, block.end); 18: // put the file name, index and blob into a temporary from 19: var fd = new FormData(); 20: fd.append("name", block.name); 21: fd.append("index", block.index); 22: fd.append("file", blob); 23: // post the form to backend service (asp.net mvc controller action) 24: $.ajax({ 25: url: "/Home/UploadInFormData", 26: data: fd, 27: processData: false, 28: contentType: "multipart/form-data", 29: type: "POST", 30: success: function (result) { 31: if (!result.success) { 32: alert(result.error); 33: } 34: callback(null, block.index); 35: } 36: }); 37: }); 38: }); 39: } 40: }); Then we will invoke these functions one by one by using the async.js. And once all functions had been executed successfully I invoked another ajax call to the backend service to commit all these chunks (blocks) as the blob in Windows Azure Storage. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10: // calculate the start and end byte index for each blocks(chunks) 11: // with the index, file name and index list for future using 12: ... ... 13: // define the function array and push all chunk upload operation into this array 14: ... ... 15: // invoke the functions one by one 16: // then invoke the commit ajax call to put blocks into blob in azure storage 17: async.series(putBlocks, function (error, result) { 18: var data = { 19: name: fileName, 20: list: list 21: }; 22: $.post("/Home/Commit", data, function (result) { 23: if (!result.success) { 24: alert(result.error); 25: } 26: else { 27: alert("done!"); 28: } 29: }); 30: }); 31: } 32: }); That’s all in the client side. The outline of our logic would be - Calculate the start and end byte index for each chunks based on the block size. - Defined the functions of reading the chunk form file and upload the content to the backend service through ajax. - Execute the functions defined in previous step with “async.js”. - Commit the chunks by invoking the backend service in Windows Azure Storage finally.   Save Chunks as Blocks into Blob Storage In above we finished the client size JavaScript code. It uploaded the file in chunks to the backend service which we are going to implement in this step. We will use ASP.NET MVC as our backend service, and it will receive the chunks, upload into Windows Azure Bob Storage in blocks, then finally commit as one blob. As in the client side we uploaded chunks by invoking the ajax call to the URL "/Home/UploadInFormData", I created a new action under the Index controller and it only accepts HTTP POST request. 1: [HttpPost] 2: public JsonResult UploadInFormData() 3: { 4: var error = string.Empty; 5: try 6: { 7: } 8: catch (Exception e) 9: { 10: error = e.ToString(); 11: } 12:  13: return new JsonResult() 14: { 15: Data = new 16: { 17: success = string.IsNullOrWhiteSpace(error), 18: error = error 19: } 20: }; 21: } Then I retrieved the file name, index and the chunk content from the Request.Form object, which was passed from our client side. And then, used the Windows Azure SDK to create a blob container (in this case we will use the container named “test”.) and create a blob reference with the blob name (same as the file name). Then uploaded the chunk as a block of this blob with the index, since in Blob Storage each block must have an index (ID) associated with so that finally we can put all blocks as one blob by specifying their block ID list. 1: [HttpPost] 2: public JsonResult UploadInFormData() 3: { 4: var error = string.Empty; 5: try 6: { 7: var name = Request.Form["name"]; 8: var index = int.Parse(Request.Form["index"]); 9: var file = Request.Files[0]; 10: var id = Convert.ToBase64String(BitConverter.GetBytes(index)); 11:  12: var container = _client.GetContainerReference("test"); 13: container.CreateIfNotExists(); 14: var blob = container.GetBlockBlobReference(name); 15: blob.PutBlock(id, file.InputStream, null); 16: } 17: catch (Exception e) 18: { 19: error = e.ToString(); 20: } 21:  22: return new JsonResult() 23: { 24: Data = new 25: { 26: success = string.IsNullOrWhiteSpace(error), 27: error = error 28: } 29: }; 30: } Next, I created another action to commit the blocks into blob once all chunks had been uploaded. Similarly, I retrieved the blob name from the Request.Form. I also retrieved the chunks ID list, which is the block ID list from the Request.Form in a string format, split them as a list, then invoked the BlockBlob.PutBlockList method. After that our blob will be shown in the container and ready to be download. 1: [HttpPost] 2: public JsonResult Commit() 3: { 4: var error = string.Empty; 5: try 6: { 7: var name = Request.Form["name"]; 8: var list = Request.Form["list"]; 9: var ids = list 10: .Split(',') 11: .Where(id => !string.IsNullOrWhiteSpace(id)) 12: .Select(id => Convert.ToBase64String(BitConverter.GetBytes(int.Parse(id)))) 13: .ToArray(); 14:  15: var container = _client.GetContainerReference("test"); 16: container.CreateIfNotExists(); 17: var blob = container.GetBlockBlobReference(name); 18: blob.PutBlockList(ids); 19: } 20: catch (Exception e) 21: { 22: error = e.ToString(); 23: } 24:  25: return new JsonResult() 26: { 27: Data = new 28: { 29: success = string.IsNullOrWhiteSpace(error), 30: error = error 31: } 32: }; 33: } Now we finished all code we need. The whole process of uploading would be like this below. Below is the full client side JavaScript code. 1: <script type="text/javascript" src="~/Scripts/async.js"></script> 2: <script type="text/javascript"> 3: $(function () { 4: $("#upload_button_blob").click(function () { 5: // assert the browser support html5 6: if (window.File && window.Blob && window.FormData) { 7: alert("Your brwoser is awesome, let's rock!"); 8: } 9: else { 10: alert("Oh man plz update to a modern browser before try is cool stuff out."); 11: return; 12: } 13:  14: // start to upload each files in chunks 15: var files = $("#upload_files")[0].files; 16: for (var i = 0; i < files.length; i++) { 17: var file = files[i]; 18: var fileSize = file.size; 19: var fileName = file.name; 20:  21: // calculate the start and end byte index for each blocks(chunks) 22: // with the index, file name and index list for future using 23: var blockSizeInKB = $("#block_size").val(); 24: var blockSize = blockSizeInKB * 1024; 25: var blocks = []; 26: var offset = 0; 27: var index = 0; 28: var list = ""; 29: while (offset < fileSize) { 30: var start = offset; 31: var end = Math.min(offset + blockSize, fileSize); 32:  33: blocks.push({ 34: name: fileName, 35: index: index, 36: start: start, 37: end: end 38: }); 39: list += index + ","; 40:  41: offset = end; 42: index++; 43: } 44:  45: // define the function array and push all chunk upload operation into this array 46: var putBlocks = []; 47: blocks.forEach(function (block) { 48: putBlocks.push(function (callback) { 49: // load blob based on the start and end index for each chunks 50: var blob = file.slice(block.start, block.end); 51: // put the file name, index and blob into a temporary from 52: var fd = new FormData(); 53: fd.append("name", block.name); 54: fd.append("index", block.index); 55: fd.append("file", blob); 56: // post the form to backend service (asp.net mvc controller action) 57: $.ajax({ 58: url: "/Home/UploadInFormData", 59: data: fd, 60: processData: false, 61: contentType: "multipart/form-data", 62: type: "POST", 63: success: function (result) { 64: if (!result.success) { 65: alert(result.error); 66: } 67: callback(null, block.index); 68: } 69: }); 70: }); 71: }); 72:  73: // invoke the functions one by one 74: // then invoke the commit ajax call to put blocks into blob in azure storage 75: async.series(putBlocks, function (error, result) { 76: var data = { 77: name: fileName, 78: list: list 79: }; 80: $.post("/Home/Commit", data, function (result) { 81: if (!result.success) { 82: alert(result.error); 83: } 84: else { 85: alert("done!"); 86: } 87: }); 88: }); 89: } 90: }); 91: }); 92: </script> And below is the full ASP.NET MVC controller code. 1: public class HomeController : Controller 2: { 3: private CloudStorageAccount _account; 4: private CloudBlobClient _client; 5:  6: public HomeController() 7: : base() 8: { 9: _account = CloudStorageAccount.Parse(CloudConfigurationManager.GetSetting("DataConnectionString")); 10: _client = _account.CreateCloudBlobClient(); 11: } 12:  13: public ActionResult Index() 14: { 15: ViewBag.Message = "Modify this template to jump-start your ASP.NET MVC application."; 16:  17: return View(); 18: } 19:  20: [HttpPost] 21: public JsonResult UploadInFormData() 22: { 23: var error = string.Empty; 24: try 25: { 26: var name = Request.Form["name"]; 27: var index = int.Parse(Request.Form["index"]); 28: var file = Request.Files[0]; 29: var id = Convert.ToBase64String(BitConverter.GetBytes(index)); 30:  31: var container = _client.GetContainerReference("test"); 32: container.CreateIfNotExists(); 33: var blob = container.GetBlockBlobReference(name); 34: blob.PutBlock(id, file.InputStream, null); 35: } 36: catch (Exception e) 37: { 38: error = e.ToString(); 39: } 40:  41: return new JsonResult() 42: { 43: Data = new 44: { 45: success = string.IsNullOrWhiteSpace(error), 46: error = error 47: } 48: }; 49: } 50:  51: [HttpPost] 52: public JsonResult Commit() 53: { 54: var error = string.Empty; 55: try 56: { 57: var name = Request.Form["name"]; 58: var list = Request.Form["list"]; 59: var ids = list 60: .Split(',') 61: .Where(id => !string.IsNullOrWhiteSpace(id)) 62: .Select(id => Convert.ToBase64String(BitConverter.GetBytes(int.Parse(id)))) 63: .ToArray(); 64:  65: var container = _client.GetContainerReference("test"); 66: container.CreateIfNotExists(); 67: var blob = container.GetBlockBlobReference(name); 68: blob.PutBlockList(ids); 69: } 70: catch (Exception e) 71: { 72: error = e.ToString(); 73: } 74:  75: return new JsonResult() 76: { 77: Data = new 78: { 79: success = string.IsNullOrWhiteSpace(error), 80: error = error 81: } 82: }; 83: } 84: } And if we selected a file from the browser we will see our application will upload chunks in the size we specified to the server through ajax call in background, and then commit all chunks in one blob. Then we can find the blob in our Windows Azure Blob Storage.   Optimized by Parallel Upload In previous example we just uploaded our file in chunks. This solved the problem that ASP.NET MVC request content size limitation as well as the Windows Azure load balancer timeout. But it might introduce the performance problem since we uploaded chunks in sequence. In order to improve the upload performance we could modify our client side code a bit to make the upload operation invoked in parallel. The good news is that, “async.js” library provides the parallel execution function. If you remembered the code we invoke the service to upload chunks, it utilized “async.series” which means all functions will be executed in sequence. Now we will change this code to “async.parallel”. This will invoke all functions in parallel. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10: // calculate the start and end byte index for each blocks(chunks) 11: // with the index, file name and index list for future using 12: ... ... 13: // define the function array and push all chunk upload operation into this array 14: ... ... 15: // invoke the functions one by one 16: // then invoke the commit ajax call to put blocks into blob in azure storage 17: async.parallel(putBlocks, function (error, result) { 18: var data = { 19: name: fileName, 20: list: list 21: }; 22: $.post("/Home/Commit", data, function (result) { 23: if (!result.success) { 24: alert(result.error); 25: } 26: else { 27: alert("done!"); 28: } 29: }); 30: }); 31: } 32: }); In this way all chunks will be uploaded to the server side at the same time to maximize the bandwidth usage. This should work if the file was not very large and the chunk size was not very small. But for large file this might introduce another problem that too many ajax calls are sent to the server at the same time. So the best solution should be, upload the chunks in parallel with maximum concurrency limitation. The code below specified the concurrency limitation to 4, which means at the most only 4 ajax calls could be invoked at the same time. 1: $("#upload_button_blob").click(function () { 2: // assert the browser support html5 3: ... ... 4: // start to upload each files in chunks 5: var files = $("#upload_files")[0].files; 6: for (var i = 0; i < files.length; i++) { 7: var file = files[i]; 8: var fileSize = file.size; 9: var fileName = file.name; 10: // calculate the start and end byte index for each blocks(chunks) 11: // with the index, file name and index list for future using 12: ... ... 13: // define the function array and push all chunk upload operation into this array 14: ... ... 15: // invoke the functions one by one 16: // then invoke the commit ajax call to put blocks into blob in azure storage 17: async.parallelLimit(putBlocks, 4, function (error, result) { 18: var data = { 19: name: fileName, 20: list: list 21: }; 22: $.post("/Home/Commit", data, function (result) { 23: if (!result.success) { 24: alert(result.error); 25: } 26: else { 27: alert("done!"); 28: } 29: }); 30: }); 31: } 32: });   Summary In this post we discussed how to upload files in chunks to the backend service and then upload them into Windows Azure Blob Storage in blocks. We focused on the frontend side and leverage three new feature introduced in HTML 5 which are - File.slice: Read part of the file by specifying the start and end byte index. - Blob: File-like interface which contains the part of the file content. - FormData: Temporary form element that we can pass the chunk alone with some metadata to the backend service. Then we discussed the performance consideration of chunk uploading. Sequence upload cannot provide maximized upload speed, but the unlimited parallel upload might crash the browser and server if too many chunks. So we finally came up with the solution to upload chunks in parallel with the concurrency limitation. We also demonstrated how to utilize “async.js” JavaScript library to help us control the asynchronize call and the parallel limitation.   Regarding the chunk size and the parallel limitation value there is no “best” value. You need to test vary composition and find out the best one for your particular scenario. It depends on the local bandwidth, client machine cores and the server side (Windows Azure Cloud Service Virtual Machine) cores, memory and bandwidth. Below is one of my performance test result. The client machine was Windows 8 IE 10 with 4 cores. I was using Microsoft Cooperation Network. The web site was hosted on Windows Azure China North data center (in Beijing) with one small web role (1.7GB 1 core CPU, 1.75GB memory with 100Mbps bandwidth). The test cases were - Chunk size: 512KB, 1MB, 2MB, 4MB. - Upload Mode: Sequence, parallel (unlimited), parallel with limit (4 threads, 8 threads). - Chunk Format: base64 string, binaries. - Target file: 100MB. - Each case was tested 3 times. Below is the test result chart. Some thoughts, but not guidance or best practice: - Parallel gets better performance than series. - No significant performance improvement between parallel 4 threads and 8 threads. - Transform with binaries provides better performance than base64. - In all cases, chunk size in 1MB - 2MB gets better performance.   Hope this helps, Shaun All documents and related graphics, codes are provided "AS IS" without warranty of any kind. Copyright © Shaun Ziyan Xu. This work is licensed under the Creative Commons License.

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• How LINQ to Object statements work

  - by rajbk

  This post goes into detail as to now LINQ statements work when querying a collection of objects. This topic assumes you have an understanding of how generics, delegates, implicitly typed variables, lambda expressions, object/collection initializers, extension methods and the yield statement work. I would also recommend you read my previous two posts: Using Delegates in C# Part 1 Using Delegates in C# Part 2 We will start by writing some methods to filter a collection of data. Assume we have an Employee class like so: 1: public class Employee { 2: public int ID { get; set;} 3: public string FirstName { get; set;} 4: public string LastName {get; set;} 5: public string Country { get; set; } 6: } and a collection of employees like so: 1: var employees = new List<Employee> { 2: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 3: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 4: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 5: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" }, 6: }; Filtering We wish to  find all employees that have an even ID. We could start off by writing a method that takes in a list of employees and returns a filtered list of employees with an even ID. 1: static List<Employee> GetEmployeesWithEvenID(List<Employee> employees) { 2: var filteredEmployees = new List<Employee>(); 3: foreach (Employee emp in employees) { 4: if (emp.ID % 2 == 0) { 5: filteredEmployees.Add(emp); 6: } 7: } 8: return filteredEmployees; 9: } The method can be rewritten to return an IEnumerable<Employee> using the yield return keyword. 1: static IEnumerable<Employee> GetEmployeesWithEvenID(IEnumerable<Employee> employees) { 2: foreach (Employee emp in employees) { 3: if (emp.ID % 2 == 0) { 4: yield return emp; 5: } 6: } 7: } We put these together in a console application. 1: using System; 2: using System.Collections.Generic; 3: //No System.Linq 4:  5: public class Program 6: { 7: [STAThread] 8: static void Main(string[] args) 9: { 10: var employees = new List<Employee> { 11: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 12: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 13: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 14: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" }, 15: }; 16: var filteredEmployees = GetEmployeesWithEvenID(employees); 17:  18: foreach (Employee emp in filteredEmployees) { 19: Console.WriteLine("ID {0} First_Name {1} Last_Name {2} Country {3}", 20: emp.ID, emp.FirstName, emp.LastName, emp.Country); 21: } 22:  23: Console.ReadLine(); 24: } 25: 26: static IEnumerable<Employee> GetEmployeesWithEvenID(IEnumerable<Employee> employees) { 27: foreach (Employee emp in employees) { 28: if (emp.ID % 2 == 0) { 29: yield return emp; 30: } 31: } 32: } 33: } 34:  35: public class Employee { 36: public int ID { get; set;} 37: public string FirstName { get; set;} 38: public string LastName {get; set;} 39: public string Country { get; set; } 40: } Output: ID 2 First_Name Jim Last_Name Ashlock Country UK ID 4 First_Name Jill Last_Name Anderson Country AUS Our filtering method is too specific. Let us change it so that it is capable of doing different types of filtering and lets give our method the name Where ;-) We will add another parameter to our Where method. This additional parameter will be a delegate with the following declaration. public delegate bool Filter(Employee emp); The idea is that the delegate parameter in our Where method will point to a method that contains the logic to do our filtering thereby freeing our Where method from any dependency. The method is shown below: 1: static IEnumerable<Employee> Where(IEnumerable<Employee> employees, Filter filter) { 2: foreach (Employee emp in employees) { 3: if (filter(emp)) { 4: yield return emp; 5: } 6: } 7: } Making the change to our app, we create a new instance of the Filter delegate on line 14 with a target set to the method EmployeeHasEvenId. Running the code will produce the same output. 1: public delegate bool Filter(Employee emp); 2:  3: public class Program 4: { 5: [STAThread] 6: static void Main(string[] args) 7: { 8: var employees = new List<Employee> { 9: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 10: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 11: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 12: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 13: }; 14: var filterDelegate = new Filter(EmployeeHasEvenId); 15: var filteredEmployees = Where(employees, filterDelegate); 16:  17: foreach (Employee emp in filteredEmployees) { 18: Console.WriteLine("ID {0} First_Name {1} Last_Name {2} Country {3}", 19: emp.ID, emp.FirstName, emp.LastName, emp.Country); 20: } 21: Console.ReadLine(); 22: } 23: 24: static bool EmployeeHasEvenId(Employee emp) { 25: return emp.ID % 2 == 0; 26: } 27: 28: static IEnumerable<Employee> Where(IEnumerable<Employee> employees, Filter filter) { 29: foreach (Employee emp in employees) { 30: if (filter(emp)) { 31: yield return emp; 32: } 33: } 34: } 35: } 36:  37: public class Employee { 38: public int ID { get; set;} 39: public string FirstName { get; set;} 40: public string LastName {get; set;} 41: public string Country { get; set; } 42: } Lets use lambda expressions to inline the contents of the EmployeeHasEvenId method in place of the method. The next code snippet shows this change (see line 15).  For brevity, the Employee class declaration has been skipped. 1: public delegate bool Filter(Employee emp); 2:  3: public class Program 4: { 5: [STAThread] 6: static void Main(string[] args) 7: { 8: var employees = new List<Employee> { 9: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 10: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 11: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 12: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 13: }; 14: var filterDelegate = new Filter(EmployeeHasEvenId); 15: var filteredEmployees = Where(employees, emp => emp.ID % 2 == 0); 16:  17: foreach (Employee emp in filteredEmployees) { 18: Console.WriteLine("ID {0} First_Name {1} Last_Name {2} Country {3}", 19: emp.ID, emp.FirstName, emp.LastName, emp.Country); 20: } 21: Console.ReadLine(); 22: } 23: 24: static bool EmployeeHasEvenId(Employee emp) { 25: return emp.ID % 2 == 0; 26: } 27: 28: static IEnumerable<Employee> Where(IEnumerable<Employee> employees, Filter filter) { 29: foreach (Employee emp in employees) { 30: if (filter(emp)) { 31: yield return emp; 32: } 33: } 34: } 35: } 36:  The output displays the same two employees.  Our Where method is too restricted since it works with a collection of Employees only. Lets change it so that it works with any IEnumerable<T>. In addition, you may recall from my previous post,  that .NET 3.5 comes with a lot of predefined delegates including public delegate TResult Func<T, TResult>(T arg); We will get rid of our Filter delegate and use the one above instead. We apply these two changes to our code. 1: public class Program 2: { 3: [STAThread] 4: static void Main(string[] args) 5: { 6: var employees = new List<Employee> { 7: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 8: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 9: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 10: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 11: }; 12:  13: var filteredEmployees = Where(employees, emp => emp.ID % 2 == 0); 14:  15: foreach (Employee emp in filteredEmployees) { 16: Console.WriteLine("ID {0} First_Name {1} Last_Name {2} Country {3}", 17: emp.ID, emp.FirstName, emp.LastName, emp.Country); 18: } 19: Console.ReadLine(); 20: } 21: 22: static IEnumerable<T> Where<T>(IEnumerable<T> source, Func<T, bool> filter) { 23: foreach (var x in source) { 24: if (filter(x)) { 25: yield return x; 26: } 27: } 28: } 29: } We have successfully implemented a way to filter any IEnumerable<T> based on a  filter criteria. Projection Now lets enumerate on the items in the IEnumerable<Employee> we got from the Where method and copy them into a new IEnumerable<EmployeeFormatted>. The EmployeeFormatted class will only have a FullName and ID property. 1: public class EmployeeFormatted { 2: public int ID { get; set; } 3: public string FullName {get; set;} 4: } We could “project” our existing IEnumerable<Employee> into a new collection of IEnumerable<EmployeeFormatted> with the help of a new method. We will call this method Select ;-) 1: static IEnumerable<EmployeeFormatted> Select(IEnumerable<Employee> employees) { 2: foreach (var emp in employees) { 3: yield return new EmployeeFormatted { 4: ID = emp.ID, 5: FullName = emp.LastName + ", " + emp.FirstName 6: }; 7: } 8: } The changes are applied to our app. 1: public class Program 2: { 3: [STAThread] 4: static void Main(string[] args) 5: { 6: var employees = new List<Employee> { 7: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 8: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 9: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 10: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 11: }; 12:  13: var filteredEmployees = Where(employees, emp => emp.ID % 2 == 0); 14: var formattedEmployees = Select(filteredEmployees); 15:  16: foreach (EmployeeFormatted emp in formattedEmployees) { 17: Console.WriteLine("ID {0} Full_Name {1}", 18: emp.ID, emp.FullName); 19: } 20: Console.ReadLine(); 21: } 22:  23: static IEnumerable<T> Where<T>(IEnumerable<T> source, Func<T, bool> filter) { 24: foreach (var x in source) { 25: if (filter(x)) { 26: yield return x; 27: } 28: } 29: } 30: 31: static IEnumerable<EmployeeFormatted> Select(IEnumerable<Employee> employees) { 32: foreach (var emp in employees) { 33: yield return new EmployeeFormatted { 34: ID = emp.ID, 35: FullName = emp.LastName + ", " + emp.FirstName 36: }; 37: } 38: } 39: } 40:  41: public class Employee { 42: public int ID { get; set;} 43: public string FirstName { get; set;} 44: public string LastName {get; set;} 45: public string Country { get; set; } 46: } 47:  48: public class EmployeeFormatted { 49: public int ID { get; set; } 50: public string FullName {get; set;} 51: } Output: ID 2 Full_Name Ashlock, Jim ID 4 Full_Name Anderson, Jill We have successfully selected employees who have an even ID and then shaped our data with the help of the Select method so that the final result is an IEnumerable<EmployeeFormatted>.  Lets make our Select method more generic so that the user is given the freedom to shape what the output would look like. We can do this, like before, with lambda expressions. Our Select method is changed to accept a delegate as shown below. TSource will be the type of data that comes in and TResult will be the type the user chooses (shape of data) as returned from the selector delegate. 1:  2: static IEnumerable<TResult> Select<TSource, TResult>(IEnumerable<TSource> source, Func<TSource, TResult> selector) { 3: foreach (var x in source) { 4: yield return selector(x); 5: } 6: } We see the new changes to our app. On line 15, we use lambda expression to specify the shape of the data. In this case the shape will be of type EmployeeFormatted. 1:  2: public class Program 3: { 4: [STAThread] 5: static void Main(string[] args) 6: { 7: var employees = new List<Employee> { 8: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 9: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 10: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 11: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 12: }; 13:  14: var filteredEmployees = Where(employees, emp => emp.ID % 2 == 0); 15: var formattedEmployees = Select(filteredEmployees, (emp) => 16: new EmployeeFormatted { 17: ID = emp.ID, 18: FullName = emp.LastName + ", " + emp.FirstName 19: }); 20:  21: foreach (EmployeeFormatted emp in formattedEmployees) { 22: Console.WriteLine("ID {0} Full_Name {1}", 23: emp.ID, emp.FullName); 24: } 25: Console.ReadLine(); 26: } 27: 28: static IEnumerable<T> Where<T>(IEnumerable<T> source, Func<T, bool> filter) { 29: foreach (var x in source) { 30: if (filter(x)) { 31: yield return x; 32: } 33: } 34: } 35: 36: static IEnumerable<TResult> Select<TSource, TResult>(IEnumerable<TSource> source, Func<TSource, TResult> selector) { 37: foreach (var x in source) { 38: yield return selector(x); 39: } 40: } 41: } The code outputs the same result as before. On line 14 we filter our data and on line 15 we project our data. What if we wanted to be more expressive and concise? We could combine both line 14 and 15 into one line as shown below. Assuming you had to perform several operations like this on our collection, you would end up with some very unreadable code! 1: var formattedEmployees = Select(Where(employees, emp => emp.ID % 2 == 0), (emp) => 2: new EmployeeFormatted { 3: ID = emp.ID, 4: FullName = emp.LastName + ", " + emp.FirstName 5: }); A cleaner way to write this would be to give the appearance that the Select and Where methods were part of the IEnumerable<T>. This is exactly what extension methods give us. Extension methods have to be defined in a static class. Let us make the Select and Where extension methods on IEnumerable<T> 1: public static class MyExtensionMethods { 2: static IEnumerable<T> Where<T>(this IEnumerable<T> source, Func<T, bool> filter) { 3: foreach (var x in source) { 4: if (filter(x)) { 5: yield return x; 6: } 7: } 8: } 9: 10: static IEnumerable<TResult> Select<TSource, TResult>(this IEnumerable<TSource> source, Func<TSource, TResult> selector) { 11: foreach (var x in source) { 12: yield return selector(x); 13: } 14: } 15: } The creation of the extension method makes the syntax much cleaner as shown below. We can write as many extension methods as we want and keep on chaining them using this technique. 1: var formattedEmployees = employees 2: .Where(emp => emp.ID % 2 == 0) 3: .Select (emp => new EmployeeFormatted { ID = emp.ID, FullName = emp.LastName + ", " + emp.FirstName }); Making these changes and running our code produces the same result. 1: using System; 2: using System.Collections.Generic; 3:  4: public class Program 5: { 6: [STAThread] 7: static void Main(string[] args) 8: { 9: var employees = new List<Employee> { 10: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 11: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 12: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 13: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 14: }; 15:  16: var formattedEmployees = employees 17: .Where(emp => emp.ID % 2 == 0) 18: .Select (emp => 19: new EmployeeFormatted { 20: ID = emp.ID, 21: FullName = emp.LastName + ", " + emp.FirstName 22: } 23: ); 24:  25: foreach (EmployeeFormatted emp in formattedEmployees) { 26: Console.WriteLine("ID {0} Full_Name {1}", 27: emp.ID, emp.FullName); 28: } 29: Console.ReadLine(); 30: } 31: } 32:  33: public static class MyExtensionMethods { 34: static IEnumerable<T> Where<T>(this IEnumerable<T> source, Func<T, bool> filter) { 35: foreach (var x in source) { 36: if (filter(x)) { 37: yield return x; 38: } 39: } 40: } 41: 42: static IEnumerable<TResult> Select<TSource, TResult>(this IEnumerable<TSource> source, Func<TSource, TResult> selector) { 43: foreach (var x in source) { 44: yield return selector(x); 45: } 46: } 47: } 48:  49: public class Employee { 50: public int ID { get; set;} 51: public string FirstName { get; set;} 52: public string LastName {get; set;} 53: public string Country { get; set; } 54: } 55:  56: public class EmployeeFormatted { 57: public int ID { get; set; } 58: public string FullName {get; set;} 59: } Let’s change our code to return a collection of anonymous types and get rid of the EmployeeFormatted type. We see that the code produces the same output. 1: using System; 2: using System.Collections.Generic; 3:  4: public class Program 5: { 6: [STAThread] 7: static void Main(string[] args) 8: { 9: var employees = new List<Employee> { 10: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 11: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 12: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 13: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 14: }; 15:  16: var formattedEmployees = employees 17: .Where(emp => emp.ID % 2 == 0) 18: .Select (emp => 19: new { 20: ID = emp.ID, 21: FullName = emp.LastName + ", " + emp.FirstName 22: } 23: ); 24:  25: foreach (var emp in formattedEmployees) { 26: Console.WriteLine("ID {0} Full_Name {1}", 27: emp.ID, emp.FullName); 28: } 29: Console.ReadLine(); 30: } 31: } 32:  33: public static class MyExtensionMethods { 34: public static IEnumerable<T> Where<T>(this IEnumerable<T> source, Func<T, bool> filter) { 35: foreach (var x in source) { 36: if (filter(x)) { 37: yield return x; 38: } 39: } 40: } 41: 42: public static IEnumerable<TResult> Select<TSource, TResult>(this IEnumerable<TSource> source, Func<TSource, TResult> selector) { 43: foreach (var x in source) { 44: yield return selector(x); 45: } 46: } 47: } 48:  49: public class Employee { 50: public int ID { get; set;} 51: public string FirstName { get; set;} 52: public string LastName {get; set;} 53: public string Country { get; set; } 54: } To be more expressive, C# allows us to write our extension method calls as a query expression. Line 16 can be rewritten a query expression like so: 1: var formattedEmployees = from emp in employees 2: where emp.ID % 2 == 0 3: select new { 4: ID = emp.ID, 5: FullName = emp.LastName + ", " + emp.FirstName 6: }; When the compiler encounters an expression like the above, it simply rewrites it as calls to our extension methods.  So far we have been using our extension methods. The System.Linq namespace contains several extension methods for objects that implement the IEnumerable<T>. You can see a listing of these methods in the Enumerable class in the System.Linq namespace. Let’s get rid of our extension methods (which I purposefully wrote to be of the same signature as the ones in the Enumerable class) and use the ones provided in the Enumerable class. Our final code is shown below: 1: using System; 2: using System.Collections.Generic; 3: using System.Linq; //Added 4:  5: public class Program 6: { 7: [STAThread] 8: static void Main(string[] args) 9: { 10: var employees = new List<Employee> { 11: new Employee { ID = 1, FirstName = "John", LastName = "Wright", Country = "USA" }, 12: new Employee { ID = 2, FirstName = "Jim", LastName = "Ashlock", Country = "UK" }, 13: new Employee { ID = 3, FirstName = "Jane", LastName = "Jackson", Country = "CHE" }, 14: new Employee { ID = 4, FirstName = "Jill", LastName = "Anderson", Country = "AUS" } 15: }; 16:  17: var formattedEmployees = from emp in employees 18: where emp.ID % 2 == 0 19: select new { 20: ID = emp.ID, 21: FullName = emp.LastName + ", " + emp.FirstName 22: }; 23:  24: foreach (var emp in formattedEmployees) { 25: Console.WriteLine("ID {0} Full_Name {1}", 26: emp.ID, emp.FullName); 27: } 28: Console.ReadLine(); 29: } 30: } 31:  32: public class Employee { 33: public int ID { get; set;} 34: public string FirstName { get; set;} 35: public string LastName {get; set;} 36: public string Country { get; set; } 37: } 38:  39: public class EmployeeFormatted { 40: public int ID { get; set; } 41: public string FullName {get; set;} 42: } This post has shown you a basic overview of LINQ to Objects work by showning you how an expression is converted to a sequence of calls to extension methods when working directly with objects. It gets more interesting when working with LINQ to SQL where an expression tree is constructed – an in memory data representation of the expression. The C# compiler compiles these expressions into code that builds an expression tree at runtime. The provider can then traverse the expression tree and generate the appropriate SQL query. You can read more about expression trees in this MSDN article.

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• Introduction to the ASP.NET Web API

  - by Stephen.Walther

  I am a huge fan of Ajax. If you want to create a great experience for the users of your website – regardless of whether you are building an ASP.NET MVC or an ASP.NET Web Forms site — then you need to use Ajax. Otherwise, you are just being cruel to your customers. We use Ajax extensively in several of the ASP.NET applications that my company, Superexpert.com, builds. We expose data from the server as JSON and use jQuery to retrieve and update that data from the browser. One challenge, when building an ASP.NET website, is deciding on which technology to use to expose JSON data from the server. For example, how do you expose a list of products from the server as JSON so you can retrieve the list of products with jQuery? You have a number of options (too many options) including ASMX Web services, WCF Web Services, ASHX Generic Handlers, WCF Data Services, and MVC controller actions. Fortunately, the world has just been simplified. With the release of ASP.NET 4 Beta, Microsoft has introduced a new technology for exposing JSON from the server named the ASP.NET Web API. You can use the ASP.NET Web API with both ASP.NET MVC and ASP.NET Web Forms applications. The goal of this blog post is to provide you with a brief overview of the features of the new ASP.NET Web API. You learn how to use the ASP.NET Web API to retrieve, insert, update, and delete database records with jQuery. We also discuss how you can perform form validation when using the Web API and use OData when using the Web API. Creating an ASP.NET Web API Controller The ASP.NET Web API exposes JSON data through a new type of controller called an API controller. You can add an API controller to an existing ASP.NET MVC 4 project through the standard Add Controller dialog box. Right-click your Controllers folder and select Add, Controller. In the dialog box, name your controller MovieController and select the Empty API controller template: A brand new API controller looks like this: using System; using System.Collections.Generic; using System.Linq; using System.Net.Http; using System.Web.Http; namespace MyWebAPIApp.Controllers { public class MovieController : ApiController { } } An API controller, unlike a standard MVC controller, derives from the base ApiController class instead of the base Controller class. Using jQuery to Retrieve, Insert, Update, and Delete Data Let’s create an Ajaxified Movie Database application. We’ll retrieve, insert, update, and delete movies using jQuery with the MovieController which we just created. Our Movie model class looks like this: namespace MyWebAPIApp.Models { public class Movie { public int Id { get; set; } public string Title { get; set; } public string Director { get; set; } } } Our application will consist of a single HTML page named Movies.html. We’ll place all of our jQuery code in the Movies.html page. Getting a Single Record with the ASP.NET Web API To support retrieving a single movie from the server, we need to add a Get method to our API controller: using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Net.Http; using System.Web.Http; using MyWebAPIApp.Models; namespace MyWebAPIApp.Controllers { public class MovieController : ApiController { public Movie GetMovie(int id) { // Return movie by id if (id == 1) { return new Movie { Id = 1, Title = "Star Wars", Director = "Lucas" }; } // Otherwise, movie was not found throw new HttpResponseException(HttpStatusCode.NotFound); } } } In the code above, the GetMovie() method accepts the Id of a movie. If the Id has the value 1 then the method returns the movie Star Wars. Otherwise, the method throws an exception and returns 404 Not Found HTTP status code. After building your project, you can invoke the MovieController.GetMovie() method by entering the following URL in your web browser address bar: http://localhost:[port]/api/movie/1 (You’ll need to enter the correct randomly generated port). In the URL api/movie/1, the first “api” segment indicates that this is a Web API route. The “movie” segment indicates that the MovieController should be invoked. You do not specify the name of the action. Instead, the HTTP method used to make the request – GET, POST, PUT, DELETE — is used to identify the action to invoke. The ASP.NET Web API uses different routing conventions than normal ASP.NET MVC controllers. When you make an HTTP GET request then any API controller method with a name that starts with “GET” is invoked. So, we could have called our API controller action GetPopcorn() instead of GetMovie() and it would still be invoked by the URL api/movie/1. The default route for the Web API is defined in the Global.asax file and it looks like this: routes.MapHttpRoute( name: "DefaultApi", routeTemplate: "api/{controller}/{id}", defaults: new { id = RouteParameter.Optional } ); We can invoke our GetMovie() controller action with the jQuery code in the following HTML page: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Get Movie</title> </head> <body> <div> Title: <span id="title"></span> </div> <div> Director: <span id="director"></span> </div> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> getMovie(1, function (movie) { $("#title").html(movie.Title); $("#director").html(movie.Director); }); function getMovie(id, callback) { $.ajax({ url: "/api/Movie", data: { id: id }, type: "GET", contentType: "application/json;charset=utf-8", statusCode: { 200: function (movie) { callback(movie); }, 404: function () { alert("Not Found!"); } } }); } </script> </body> </html> In the code above, the jQuery $.ajax() method is used to invoke the GetMovie() method. Notice that the Ajax call handles two HTTP response codes. When the GetMove() method successfully returns a movie, the method returns a 200 status code. In that case, the details of the movie are displayed in the HTML page. Otherwise, if the movie is not found, the GetMovie() method returns a 404 status code. In that case, the page simply displays an alert box indicating that the movie was not found (hopefully, you would implement something more graceful in an actual application). You can use your browser’s Developer Tools to see what is going on in the background when you open the HTML page (hit F12 in the most recent version of most browsers). For example, you can use the Network tab in Google Chrome to see the Ajax request which invokes the GetMovie() method: Getting a Set of Records with the ASP.NET Web API Let’s modify our Movie API controller so that it returns a collection of movies. The following Movie controller has a new ListMovies() method which returns a (hard-coded) collection of movies: using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Net.Http; using System.Web.Http; using MyWebAPIApp.Models; namespace MyWebAPIApp.Controllers { public class MovieController : ApiController { public IEnumerable<Movie> ListMovies() { return new List<Movie> { new Movie {Id=1, Title="Star Wars", Director="Lucas"}, new Movie {Id=1, Title="King Kong", Director="Jackson"}, new Movie {Id=1, Title="Memento", Director="Nolan"} }; } } } Because we named our action ListMovies(), the default Web API route will never match it. Therefore, we need to add the following custom route to our Global.asax file (at the top of the RegisterRoutes() method): routes.MapHttpRoute( name: "ActionApi", routeTemplate: "api/{controller}/{action}/{id}", defaults: new { id = RouteParameter.Optional } ); This route enables us to invoke the ListMovies() method with the URL /api/movie/listmovies. Now that we have exposed our collection of movies from the server, we can retrieve and display the list of movies using jQuery in our HTML page: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>List Movies</title> </head> <body> <div id="movies"></div> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> listMovies(function (movies) { var strMovies=""; $.each(movies, function (index, movie) { strMovies += "<div>" + movie.Title + "</div>"; }); $("#movies").html(strMovies); }); function listMovies(callback) { $.ajax({ url: "/api/Movie/ListMovies", data: {}, type: "GET", contentType: "application/json;charset=utf-8", }).then(function(movies){ callback(movies); }); } </script> </body> </html>     Inserting a Record with the ASP.NET Web API Now let’s modify our Movie API controller so it supports creating new records: public HttpResponseMessage<Movie> PostMovie(Movie movieToCreate) { // Add movieToCreate to the database and update primary key movieToCreate.Id = 23; // Build a response that contains the location of the new movie var response = new HttpResponseMessage<Movie>(movieToCreate, HttpStatusCode.Created); var relativePath = "/api/movie/" + movieToCreate.Id; response.Headers.Location = new Uri(Request.RequestUri, relativePath); return response; } The PostMovie() method in the code above accepts a movieToCreate parameter. We don’t actually store the new movie anywhere. In real life, you will want to call a service method to store the new movie in a database. When you create a new resource, such as a new movie, you should return the location of the new resource. In the code above, the URL where the new movie can be retrieved is assigned to the Location header returned in the PostMovie() response. Because the name of our method starts with “Post”, we don’t need to create a custom route. The PostMovie() method can be invoked with the URL /Movie/PostMovie – just as long as the method is invoked within the context of a HTTP POST request. The following HTML page invokes the PostMovie() method. <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Create Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> var movieToCreate = { title: "The Hobbit", director: "Jackson" }; createMovie(movieToCreate, function (newMovie) { alert("New movie created with an Id of " + newMovie.Id); }); function createMovie(movieToCreate, callback) { $.ajax({ url: "/api/Movie", data: JSON.stringify( movieToCreate ), type: "POST", contentType: "application/json;charset=utf-8", statusCode: { 201: function (newMovie) { callback(newMovie); } } }); } </script> </body> </html> This page creates a new movie (the Hobbit) by calling the createMovie() method. The page simply displays the Id of the new movie: The HTTP Post operation is performed with the following call to the jQuery $.ajax() method: $.ajax({ url: "/api/Movie", data: JSON.stringify( movieToCreate ), type: "POST", contentType: "application/json;charset=utf-8", statusCode: { 201: function (newMovie) { callback(newMovie); } } }); Notice that the type of Ajax request is a POST request. This is required to match the PostMovie() method. Notice, furthermore, that the new movie is converted into JSON using JSON.stringify(). The JSON.stringify() method takes a JavaScript object and converts it into a JSON string. Finally, notice that success is represented with a 201 status code. The HttpStatusCode.Created value returned from the PostMovie() method returns a 201 status code. Updating a Record with the ASP.NET Web API Here’s how we can modify the Movie API controller to support updating an existing record. In this case, we need to create a PUT method to handle an HTTP PUT request: public void PutMovie(Movie movieToUpdate) { if (movieToUpdate.Id == 1) { // Update the movie in the database return; } // If you can't find the movie to update throw new HttpResponseException(HttpStatusCode.NotFound); } Unlike our PostMovie() method, the PutMovie() method does not return a result. The action either updates the database or, if the movie cannot be found, returns an HTTP Status code of 404. The following HTML page illustrates how you can invoke the PutMovie() method: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Put Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> var movieToUpdate = { id: 1, title: "The Hobbit", director: "Jackson" }; updateMovie(movieToUpdate, function () { alert("Movie updated!"); }); function updateMovie(movieToUpdate, callback) { $.ajax({ url: "/api/Movie", data: JSON.stringify(movieToUpdate), type: "PUT", contentType: "application/json;charset=utf-8", statusCode: { 200: function () { callback(); }, 404: function () { alert("Movie not found!"); } } }); } </script> </body> </html> Deleting a Record with the ASP.NET Web API Here’s the code for deleting a movie: public HttpResponseMessage DeleteMovie(int id) { // Delete the movie from the database // Return status code return new HttpResponseMessage(HttpStatusCode.NoContent); } This method simply deletes the movie (well, not really, but pretend that it does) and returns a No Content status code (204). The following page illustrates how you can invoke the DeleteMovie() action: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Delete Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> deleteMovie(1, function () { alert("Movie deleted!"); }); function deleteMovie(id, callback) { $.ajax({ url: "/api/Movie", data: JSON.stringify({id:id}), type: "DELETE", contentType: "application/json;charset=utf-8", statusCode: { 204: function () { callback(); } } }); } </script> </body> </html> Performing Validation How do you perform form validation when using the ASP.NET Web API? Because validation in ASP.NET MVC is driven by the Default Model Binder, and because the Web API uses the Default Model Binder, you get validation for free. Let’s modify our Movie class so it includes some of the standard validation attributes: using System.ComponentModel.DataAnnotations; namespace MyWebAPIApp.Models { public class Movie { public int Id { get; set; } [Required(ErrorMessage="Title is required!")] [StringLength(5, ErrorMessage="Title cannot be more than 5 characters!")] public string Title { get; set; } [Required(ErrorMessage="Director is required!")] public string Director { get; set; } } } In the code above, the Required validation attribute is used to make both the Title and Director properties required. The StringLength attribute is used to require the length of the movie title to be no more than 5 characters. Now let’s modify our PostMovie() action to validate a movie before adding the movie to the database: public HttpResponseMessage PostMovie(Movie movieToCreate) { // Validate movie if (!ModelState.IsValid) { var errors = new JsonArray(); foreach (var prop in ModelState.Values) { if (prop.Errors.Any()) { errors.Add(prop.Errors.First().ErrorMessage); } } return new HttpResponseMessage<JsonValue>(errors, HttpStatusCode.BadRequest); } // Add movieToCreate to the database and update primary key movieToCreate.Id = 23; // Build a response that contains the location of the new movie var response = new HttpResponseMessage<Movie>(movieToCreate, HttpStatusCode.Created); var relativePath = "/api/movie/" + movieToCreate.Id; response.Headers.Location = new Uri(Request.RequestUri, relativePath); return response; } If ModelState.IsValid has the value false then the errors in model state are copied to a new JSON array. Each property – such as the Title and Director property — can have multiple errors. In the code above, only the first error message is copied over. The JSON array is returned with a Bad Request status code (400 status code). The following HTML page illustrates how you can invoke our modified PostMovie() action and display any error messages: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Create Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> var movieToCreate = { title: "The Hobbit", director: "" }; createMovie(movieToCreate, function (newMovie) { alert("New movie created with an Id of " + newMovie.Id); }, function (errors) { var strErrors = ""; $.each(errors, function(index, err) { strErrors += "*" + err + "\n"; }); alert(strErrors); } ); function createMovie(movieToCreate, success, fail) { $.ajax({ url: "/api/Movie", data: JSON.stringify(movieToCreate), type: "POST", contentType: "application/json;charset=utf-8", statusCode: { 201: function (newMovie) { success(newMovie); }, 400: function (xhr) { var errors = JSON.parse(xhr.responseText); fail(errors); } } }); } </script> </body> </html> The createMovie() function performs an Ajax request and handles either a 201 or a 400 status code from the response. If a 201 status code is returned then there were no validation errors and the new movie was created. If, on the other hand, a 400 status code is returned then there was a validation error. The validation errors are retrieved from the XmlHttpRequest responseText property. The error messages are displayed in an alert: (Please don’t use JavaScript alert dialogs to display validation errors, I just did it this way out of pure laziness) This validation code in our PostMovie() method is pretty generic. There is nothing specific about this code to the PostMovie() method. In the following video, Jon Galloway demonstrates how to create a global Validation filter which can be used with any API controller action: http://www.asp.net/web-api/overview/web-api-routing-and-actions/video-custom-validation His validation filter looks like this: using System.Json; using System.Linq; using System.Net; using System.Net.Http; using System.Web.Http.Controllers; using System.Web.Http.Filters; namespace MyWebAPIApp.Filters { public class ValidationActionFilter:ActionFilterAttribute { public override void OnActionExecuting(HttpActionContext actionContext) { var modelState = actionContext.ModelState; if (!modelState.IsValid) { dynamic errors = new JsonObject(); foreach (var key in modelState.Keys) { var state = modelState[key]; if (state.Errors.Any()) { errors[key] = state.Errors.First().ErrorMessage; } } actionContext.Response = new HttpResponseMessage<JsonValue>(errors, HttpStatusCode.BadRequest); } } } } And you can register the validation filter in the Application_Start() method in the Global.asax file like this: GlobalConfiguration.Configuration.Filters.Add(new ValidationActionFilter()); After you register the Validation filter, validation error messages are returned from any API controller action method automatically when validation fails. You don’t need to add any special logic to any of your API controller actions to take advantage of the filter. Querying using OData The OData protocol is an open protocol created by Microsoft which enables you to perform queries over the web. The official website for OData is located here: http://odata.org For example, here are some of the query options which you can use with OData: · $orderby – Enables you to retrieve results in a certain order. · $top – Enables you to retrieve a certain number of results. · $skip – Enables you to skip over a certain number of results (use with $top for paging). · $filter – Enables you to filter the results returned. The ASP.NET Web API supports a subset of the OData protocol. You can use all of the query options listed above when interacting with an API controller. The only requirement is that the API controller action returns its data as IQueryable. For example, the following Movie controller has an action named GetMovies() which returns an IQueryable of movies: public IQueryable<Movie> GetMovies() { return new List<Movie> { new Movie {Id=1, Title="Star Wars", Director="Lucas"}, new Movie {Id=2, Title="King Kong", Director="Jackson"}, new Movie {Id=3, Title="Willow", Director="Lucas"}, new Movie {Id=4, Title="Shrek", Director="Smith"}, new Movie {Id=5, Title="Memento", Director="Nolan"} }.AsQueryable(); } If you enter the following URL in your browser: /api/movie?$top=2&$orderby=Title Then you will limit the movies returned to the top 2 in order of the movie Title. You will get the following results: By using the $top option in combination with the $skip option, you can enable client-side paging. For example, you can use $top and $skip to page through thousands of products, 10 products at a time. The $filter query option is very powerful. You can use this option to filter the results from a query. Here are some examples: Return every movie directed by Lucas: /api/movie?$filter=Director eq ‘Lucas’ Return every movie which has a title which starts with ‘S’: /api/movie?$filter=startswith(Title,’S') Return every movie which has an Id greater than 2: /api/movie?$filter=Id gt 2 The complete documentation for the $filter option is located here: http://www.odata.org/developers/protocols/uri-conventions#FilterSystemQueryOption Summary The goal of this blog entry was to provide you with an overview of the new ASP.NET Web API introduced with the Beta release of ASP.NET 4. In this post, I discussed how you can retrieve, insert, update, and delete data by using jQuery with the Web API. I also discussed how you can use the standard validation attributes with the Web API. You learned how to return validation error messages to the client and display the error messages using jQuery. Finally, we briefly discussed how the ASP.NET Web API supports the OData protocol. For example, you learned how to filter records returned from an API controller action by using the $filter query option. I’m excited about the new Web API. This is a feature which I expect to use with almost every ASP.NET application which I build in the future.

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• Introduction to the ASP.NET Web API

  - by Stephen.Walther

  I am a huge fan of Ajax. If you want to create a great experience for the users of your website – regardless of whether you are building an ASP.NET MVC or an ASP.NET Web Forms site — then you need to use Ajax. Otherwise, you are just being cruel to your customers. We use Ajax extensively in several of the ASP.NET applications that my company, Superexpert.com, builds. We expose data from the server as JSON and use jQuery to retrieve and update that data from the browser. One challenge, when building an ASP.NET website, is deciding on which technology to use to expose JSON data from the server. For example, how do you expose a list of products from the server as JSON so you can retrieve the list of products with jQuery? You have a number of options (too many options) including ASMX Web services, WCF Web Services, ASHX Generic Handlers, WCF Data Services, and MVC controller actions. Fortunately, the world has just been simplified. With the release of ASP.NET 4 Beta, Microsoft has introduced a new technology for exposing JSON from the server named the ASP.NET Web API. You can use the ASP.NET Web API with both ASP.NET MVC and ASP.NET Web Forms applications. The goal of this blog post is to provide you with a brief overview of the features of the new ASP.NET Web API. You learn how to use the ASP.NET Web API to retrieve, insert, update, and delete database records with jQuery. We also discuss how you can perform form validation when using the Web API and use OData when using the Web API. Creating an ASP.NET Web API Controller The ASP.NET Web API exposes JSON data through a new type of controller called an API controller. You can add an API controller to an existing ASP.NET MVC 4 project through the standard Add Controller dialog box. Right-click your Controllers folder and select Add, Controller. In the dialog box, name your controller MovieController and select the Empty API controller template: A brand new API controller looks like this: using System; using System.Collections.Generic; using System.Linq; using System.Net.Http; using System.Web.Http; namespace MyWebAPIApp.Controllers { public class MovieController : ApiController { } } An API controller, unlike a standard MVC controller, derives from the base ApiController class instead of the base Controller class. Using jQuery to Retrieve, Insert, Update, and Delete Data Let’s create an Ajaxified Movie Database application. We’ll retrieve, insert, update, and delete movies using jQuery with the MovieController which we just created. Our Movie model class looks like this: namespace MyWebAPIApp.Models { public class Movie { public int Id { get; set; } public string Title { get; set; } public string Director { get; set; } } } Our application will consist of a single HTML page named Movies.html. We’ll place all of our jQuery code in the Movies.html page. Getting a Single Record with the ASP.NET Web API To support retrieving a single movie from the server, we need to add a Get method to our API controller: using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Net.Http; using System.Web.Http; using MyWebAPIApp.Models; namespace MyWebAPIApp.Controllers { public class MovieController : ApiController { public Movie GetMovie(int id) { // Return movie by id if (id == 1) { return new Movie { Id = 1, Title = "Star Wars", Director = "Lucas" }; } // Otherwise, movie was not found throw new HttpResponseException(HttpStatusCode.NotFound); } } } In the code above, the GetMovie() method accepts the Id of a movie. If the Id has the value 1 then the method returns the movie Star Wars. Otherwise, the method throws an exception and returns 404 Not Found HTTP status code. After building your project, you can invoke the MovieController.GetMovie() method by entering the following URL in your web browser address bar: http://localhost:[port]/api/movie/1 (You’ll need to enter the correct randomly generated port). In the URL api/movie/1, the first “api” segment indicates that this is a Web API route. The “movie” segment indicates that the MovieController should be invoked. You do not specify the name of the action. Instead, the HTTP method used to make the request – GET, POST, PUT, DELETE — is used to identify the action to invoke. The ASP.NET Web API uses different routing conventions than normal ASP.NET MVC controllers. When you make an HTTP GET request then any API controller method with a name that starts with “GET” is invoked. So, we could have called our API controller action GetPopcorn() instead of GetMovie() and it would still be invoked by the URL api/movie/1. The default route for the Web API is defined in the Global.asax file and it looks like this: routes.MapHttpRoute( name: "DefaultApi", routeTemplate: "api/{controller}/{id}", defaults: new { id = RouteParameter.Optional } ); We can invoke our GetMovie() controller action with the jQuery code in the following HTML page: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Get Movie</title> </head> <body> <div> Title: <span id="title"></span> </div> <div> Director: <span id="director"></span> </div> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> getMovie(1, function (movie) { $("#title").html(movie.Title); $("#director").html(movie.Director); }); function getMovie(id, callback) { $.ajax({ url: "/api/Movie", data: { id: id }, type: "GET", contentType: "application/json;charset=utf-8", statusCode: { 200: function (movie) { callback(movie); }, 404: function () { alert("Not Found!"); } } }); } </script> </body> </html> In the code above, the jQuery $.ajax() method is used to invoke the GetMovie() method. Notice that the Ajax call handles two HTTP response codes. When the GetMove() method successfully returns a movie, the method returns a 200 status code. In that case, the details of the movie are displayed in the HTML page. Otherwise, if the movie is not found, the GetMovie() method returns a 404 status code. In that case, the page simply displays an alert box indicating that the movie was not found (hopefully, you would implement something more graceful in an actual application). You can use your browser’s Developer Tools to see what is going on in the background when you open the HTML page (hit F12 in the most recent version of most browsers). For example, you can use the Network tab in Google Chrome to see the Ajax request which invokes the GetMovie() method: Getting a Set of Records with the ASP.NET Web API Let’s modify our Movie API controller so that it returns a collection of movies. The following Movie controller has a new ListMovies() method which returns a (hard-coded) collection of movies: using System; using System.Collections.Generic; using System.Linq; using System.Net; using System.Net.Http; using System.Web.Http; using MyWebAPIApp.Models; namespace MyWebAPIApp.Controllers { public class MovieController : ApiController { public IEnumerable<Movie> ListMovies() { return new List<Movie> { new Movie {Id=1, Title="Star Wars", Director="Lucas"}, new Movie {Id=1, Title="King Kong", Director="Jackson"}, new Movie {Id=1, Title="Memento", Director="Nolan"} }; } } } Because we named our action ListMovies(), the default Web API route will never match it. Therefore, we need to add the following custom route to our Global.asax file (at the top of the RegisterRoutes() method): routes.MapHttpRoute( name: "ActionApi", routeTemplate: "api/{controller}/{action}/{id}", defaults: new { id = RouteParameter.Optional } ); This route enables us to invoke the ListMovies() method with the URL /api/movie/listmovies. Now that we have exposed our collection of movies from the server, we can retrieve and display the list of movies using jQuery in our HTML page: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>List Movies</title> </head> <body> <div id="movies"></div> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> listMovies(function (movies) { var strMovies=""; $.each(movies, function (index, movie) { strMovies += "<div>" + movie.Title + "</div>"; }); $("#movies").html(strMovies); }); function listMovies(callback) { $.ajax({ url: "/api/Movie/ListMovies", data: {}, type: "GET", contentType: "application/json;charset=utf-8", }).then(function(movies){ callback(movies); }); } </script> </body> </html>     Inserting a Record with the ASP.NET Web API Now let’s modify our Movie API controller so it supports creating new records: public HttpResponseMessage<Movie> PostMovie(Movie movieToCreate) { // Add movieToCreate to the database and update primary key movieToCreate.Id = 23; // Build a response that contains the location of the new movie var response = new HttpResponseMessage<Movie>(movieToCreate, HttpStatusCode.Created); var relativePath = "/api/movie/" + movieToCreate.Id; response.Headers.Location = new Uri(Request.RequestUri, relativePath); return response; } The PostMovie() method in the code above accepts a movieToCreate parameter. We don’t actually store the new movie anywhere. In real life, you will want to call a service method to store the new movie in a database. When you create a new resource, such as a new movie, you should return the location of the new resource. In the code above, the URL where the new movie can be retrieved is assigned to the Location header returned in the PostMovie() response. Because the name of our method starts with “Post”, we don’t need to create a custom route. The PostMovie() method can be invoked with the URL /Movie/PostMovie – just as long as the method is invoked within the context of a HTTP POST request. The following HTML page invokes the PostMovie() method. <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Create Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> var movieToCreate = { title: "The Hobbit", director: "Jackson" }; createMovie(movieToCreate, function (newMovie) { alert("New movie created with an Id of " + newMovie.Id); }); function createMovie(movieToCreate, callback) { $.ajax({ url: "/api/Movie", data: JSON.stringify( movieToCreate ), type: "POST", contentType: "application/json;charset=utf-8", statusCode: { 201: function (newMovie) { callback(newMovie); } } }); } </script> </body> </html> This page creates a new movie (the Hobbit) by calling the createMovie() method. The page simply displays the Id of the new movie: The HTTP Post operation is performed with the following call to the jQuery $.ajax() method: $.ajax({ url: "/api/Movie", data: JSON.stringify( movieToCreate ), type: "POST", contentType: "application/json;charset=utf-8", statusCode: { 201: function (newMovie) { callback(newMovie); } } }); Notice that the type of Ajax request is a POST request. This is required to match the PostMovie() method. Notice, furthermore, that the new movie is converted into JSON using JSON.stringify(). The JSON.stringify() method takes a JavaScript object and converts it into a JSON string. Finally, notice that success is represented with a 201 status code. The HttpStatusCode.Created value returned from the PostMovie() method returns a 201 status code. Updating a Record with the ASP.NET Web API Here’s how we can modify the Movie API controller to support updating an existing record. In this case, we need to create a PUT method to handle an HTTP PUT request: public void PutMovie(Movie movieToUpdate) { if (movieToUpdate.Id == 1) { // Update the movie in the database return; } // If you can't find the movie to update throw new HttpResponseException(HttpStatusCode.NotFound); } Unlike our PostMovie() method, the PutMovie() method does not return a result. The action either updates the database or, if the movie cannot be found, returns an HTTP Status code of 404. The following HTML page illustrates how you can invoke the PutMovie() method: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Put Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> var movieToUpdate = { id: 1, title: "The Hobbit", director: "Jackson" }; updateMovie(movieToUpdate, function () { alert("Movie updated!"); }); function updateMovie(movieToUpdate, callback) { $.ajax({ url: "/api/Movie", data: JSON.stringify(movieToUpdate), type: "PUT", contentType: "application/json;charset=utf-8", statusCode: { 200: function () { callback(); }, 404: function () { alert("Movie not found!"); } } }); } </script> </body> </html> Deleting a Record with the ASP.NET Web API Here’s the code for deleting a movie: public HttpResponseMessage DeleteMovie(int id) { // Delete the movie from the database // Return status code return new HttpResponseMessage(HttpStatusCode.NoContent); } This method simply deletes the movie (well, not really, but pretend that it does) and returns a No Content status code (204). The following page illustrates how you can invoke the DeleteMovie() action: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Delete Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> deleteMovie(1, function () { alert("Movie deleted!"); }); function deleteMovie(id, callback) { $.ajax({ url: "/api/Movie", data: JSON.stringify({id:id}), type: "DELETE", contentType: "application/json;charset=utf-8", statusCode: { 204: function () { callback(); } } }); } </script> </body> </html> Performing Validation How do you perform form validation when using the ASP.NET Web API? Because validation in ASP.NET MVC is driven by the Default Model Binder, and because the Web API uses the Default Model Binder, you get validation for free. Let’s modify our Movie class so it includes some of the standard validation attributes: using System.ComponentModel.DataAnnotations; namespace MyWebAPIApp.Models { public class Movie { public int Id { get; set; } [Required(ErrorMessage="Title is required!")] [StringLength(5, ErrorMessage="Title cannot be more than 5 characters!")] public string Title { get; set; } [Required(ErrorMessage="Director is required!")] public string Director { get; set; } } } In the code above, the Required validation attribute is used to make both the Title and Director properties required. The StringLength attribute is used to require the length of the movie title to be no more than 5 characters. Now let’s modify our PostMovie() action to validate a movie before adding the movie to the database: public HttpResponseMessage PostMovie(Movie movieToCreate) { // Validate movie if (!ModelState.IsValid) { var errors = new JsonArray(); foreach (var prop in ModelState.Values) { if (prop.Errors.Any()) { errors.Add(prop.Errors.First().ErrorMessage); } } return new HttpResponseMessage<JsonValue>(errors, HttpStatusCode.BadRequest); } // Add movieToCreate to the database and update primary key movieToCreate.Id = 23; // Build a response that contains the location of the new movie var response = new HttpResponseMessage<Movie>(movieToCreate, HttpStatusCode.Created); var relativePath = "/api/movie/" + movieToCreate.Id; response.Headers.Location = new Uri(Request.RequestUri, relativePath); return response; } If ModelState.IsValid has the value false then the errors in model state are copied to a new JSON array. Each property – such as the Title and Director property — can have multiple errors. In the code above, only the first error message is copied over. The JSON array is returned with a Bad Request status code (400 status code). The following HTML page illustrates how you can invoke our modified PostMovie() action and display any error messages: <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Create Movie</title> </head> <body> <script type="text/javascript" src="Scripts/jquery-1.6.2.min.js"></script> <script type="text/javascript"> var movieToCreate = { title: "The Hobbit", director: "" }; createMovie(movieToCreate, function (newMovie) { alert("New movie created with an Id of " + newMovie.Id); }, function (errors) { var strErrors = ""; $.each(errors, function(index, err) { strErrors += "*" + err + "n"; }); alert(strErrors); } ); function createMovie(movieToCreate, success, fail) { $.ajax({ url: "/api/Movie", data: JSON.stringify(movieToCreate), type: "POST", contentType: "application/json;charset=utf-8", statusCode: { 201: function (newMovie) { success(newMovie); }, 400: function (xhr) { var errors = JSON.parse(xhr.responseText); fail(errors); } } }); } </script> </body> </html> The createMovie() function performs an Ajax request and handles either a 201 or a 400 status code from the response. If a 201 status code is returned then there were no validation errors and the new movie was created. If, on the other hand, a 400 status code is returned then there was a validation error. The validation errors are retrieved from the XmlHttpRequest responseText property. The error messages are displayed in an alert: (Please don’t use JavaScript alert dialogs to display validation errors, I just did it this way out of pure laziness) This validation code in our PostMovie() method is pretty generic. There is nothing specific about this code to the PostMovie() method. In the following video, Jon Galloway demonstrates how to create a global Validation filter which can be used with any API controller action: http://www.asp.net/web-api/overview/web-api-routing-and-actions/video-custom-validation His validation filter looks like this: using System.Json; using System.Linq; using System.Net; using System.Net.Http; using System.Web.Http.Controllers; using System.Web.Http.Filters; namespace MyWebAPIApp.Filters { public class ValidationActionFilter:ActionFilterAttribute { public override void OnActionExecuting(HttpActionContext actionContext) { var modelState = actionContext.ModelState; if (!modelState.IsValid) { dynamic errors = new JsonObject(); foreach (var key in modelState.Keys) { var state = modelState[key]; if (state.Errors.Any()) { errors[key] = state.Errors.First().ErrorMessage; } } actionContext.Response = new HttpResponseMessage<JsonValue>(errors, HttpStatusCode.BadRequest); } } } } And you can register the validation filter in the Application_Start() method in the Global.asax file like this: GlobalConfiguration.Configuration.Filters.Add(new ValidationActionFilter()); After you register the Validation filter, validation error messages are returned from any API controller action method automatically when validation fails. You don’t need to add any special logic to any of your API controller actions to take advantage of the filter. Querying using OData The OData protocol is an open protocol created by Microsoft which enables you to perform queries over the web. The official website for OData is located here: http://odata.org For example, here are some of the query options which you can use with OData: · $orderby – Enables you to retrieve results in a certain order. · $top – Enables you to retrieve a certain number of results. · $skip – Enables you to skip over a certain number of results (use with $top for paging). · $filter – Enables you to filter the results returned. The ASP.NET Web API supports a subset of the OData protocol. You can use all of the query options listed above when interacting with an API controller. The only requirement is that the API controller action returns its data as IQueryable. For example, the following Movie controller has an action named GetMovies() which returns an IQueryable of movies: public IQueryable<Movie> GetMovies() { return new List<Movie> { new Movie {Id=1, Title="Star Wars", Director="Lucas"}, new Movie {Id=2, Title="King Kong", Director="Jackson"}, new Movie {Id=3, Title="Willow", Director="Lucas"}, new Movie {Id=4, Title="Shrek", Director="Smith"}, new Movie {Id=5, Title="Memento", Director="Nolan"} }.AsQueryable(); } If you enter the following URL in your browser: /api/movie?$top=2&$orderby=Title Then you will limit the movies returned to the top 2 in order of the movie Title. You will get the following results: By using the $top option in combination with the $skip option, you can enable client-side paging. For example, you can use $top and $skip to page through thousands of products, 10 products at a time. The $filter query option is very powerful. You can use this option to filter the results from a query. Here are some examples: Return every movie directed by Lucas: /api/movie?$filter=Director eq ‘Lucas’ Return every movie which has a title which starts with ‘S’: /api/movie?$filter=startswith(Title,’S') Return every movie which has an Id greater than 2: /api/movie?$filter=Id gt 2 The complete documentation for the $filter option is located here: http://www.odata.org/developers/protocols/uri-conventions#FilterSystemQueryOption Summary The goal of this blog entry was to provide you with an overview of the new ASP.NET Web API introduced with the Beta release of ASP.NET 4. In this post, I discussed how you can retrieve, insert, update, and delete data by using jQuery with the Web API. I also discussed how you can use the standard validation attributes with the Web API. You learned how to return validation error messages to the client and display the error messages using jQuery. Finally, we briefly discussed how the ASP.NET Web API supports the OData protocol. For example, you learned how to filter records returned from an API controller action by using the $filter query option. I’m excited about the new Web API. This is a feature which I expect to use with almost every ASP.NET application which I build in the future.

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• Windows Azure: Import/Export Hard Drives, VM ACLs, Web Sockets, Remote Debugging, Continuous Delivery, New Relic, Billing Alerts and More

  - by ScottGu

  Two weeks ago we released a giant set of improvements to Windows Azure, as well as a significant update of the Windows Azure SDK. This morning we released another massive set of enhancements to Windows Azure.  Today’s new capabilities include: Storage: Import/Export Hard Disk Drives to your Storage Accounts HDInsight: General Availability of our Hadoop Service in the cloud Virtual Machines: New VM Gallery, ACL support for VIPs Web Sites: WebSocket and Remote Debugging Support Notification Hubs: Segmented customer push notification support with tag expressions TFS & GIT: Continuous Delivery Support for Web Sites + Cloud Services Developer Analytics: New Relic support for Web Sites + Mobile Services Service Bus: Support for partitioned queues and topics Billing: New Billing Alert Service that sends emails notifications when your bill hits a threshold you define All of these improvements are now available to use immediately (note that some features are still in preview).  Below are more details about them. Storage: Import/Export Hard Disk Drives to Windows Azure I am excited to announce the preview of our new Windows Azure Import/Export Service! The Windows Azure Import/Export Service enables you to move large amounts of on-premises data into and out of your Windows Azure Storage accounts. It does this by enabling you to securely ship hard disk drives directly to our Windows Azure data centers. Once we receive the drives we’ll automatically transfer the data to or from your Windows Azure Storage account.  This enables you to import or export massive amounts of data more quickly and cost effectively (and not be constrained by available network bandwidth). Encrypted Transport Our Import/Export service provides built-in support for BitLocker disk encryption – which enables you to securely encrypt data on the hard drives before you send it, and not have to worry about it being compromised even if the disk is lost/stolen in transit (since the content on the transported hard drives is completely encrypted and you are the only one who has the key to it).  The drive preparation tool we are shipping today makes setting up bitlocker encryption on these hard drives easy. How to Import/Export your first Hard Drive of Data You can read our Getting Started Guide to learn more about how to begin using the import/export service.  You can create import and export jobs via the Windows Azure Management Portal as well as programmatically using our Server Management APIs. It is really easy to create a new import or export job using the Windows Azure Management Portal.  Simply navigate to a Windows Azure storage account, and then click the new Import/Export tab now available within it (note: if you don’t have this tab make sure to sign-up for the Import/Export preview): Then click the “Create Import Job” or “Create Export Job” commands at the bottom of it.  This will launch a wizard that easily walks you through the steps required: For more comprehensive information about Import/Export, refer to Windows Azure Storage team blog.  You can also send questions and comments to the [email protected] email address. We think you’ll find this new service makes it much easier to move data into and out of Windows Azure, and it will dramatically cut down the network bandwidth required when working on large data migration projects.  We hope you like it. HDInsight: 100% Compatible Hadoop Service in the Cloud Last week we announced the general availability release of Windows Azure HDInsight. HDInsight is a 100% compatible Hadoop service that allows you to easily provision and manage Hadoop clusters for big data processing in Windows Azure.  This release is now live in production, backed by an enterprise SLA, supported 24x7 by Microsoft Support, and is ready to use for production scenarios. HDInsight allows you to use Apache Hadoop tools, such as Pig and Hive, to process large amounts of data in Windows Azure Blob Storage. Because data is stored in Windows Azure Blob Storage, you can choose to dynamically create Hadoop clusters only when you need them, and then shut them down when they are no longer required (since you pay only for the time the Hadoop cluster instances are running this provides a super cost effective way to use them).  You can create Hadoop clusters using either the Windows Azure Management Portal (see below) or using our PowerShell and Cross Platform Command line tools: The import/export hard drive support that came out today is a perfect companion service to use with HDInsight – the combination allows you to easily ingest, process and optionally export a limitless amount of data.  We’ve also integrated HDInsight with our Business Intelligence tools, so users can leverage familiar tools like Excel in order to analyze the output of jobs.  You can find out more about how to get started with HDInsight here. Virtual Machines: VM Gallery Enhancements Today’s update of Windows Azure brings with it a new Virtual Machine gallery that you can use to create new VMs in the cloud.  You can launch the gallery by doing New->Compute->Virtual Machine->From Gallery within the Windows Azure Management Portal: The new Virtual Machine Gallery includes some nice enhancements that make it even easier to use: Search: You can now easily search and filter images using the search box in the top-right of the dialog.  For example, simply type “SQL” and we’ll filter to show those images in the gallery that contain that substring. Category Tree-view: Each month we add more built-in VM images to the gallery.  You can continue to browse these using the “All” view within the VM Gallery – or now quickly filter them using the category tree-view on the left-hand side of the dialog.  For example, by selecting “Oracle” in the tree-view you can now quickly filter to see the official Oracle supplied images. MSDN and Supported checkboxes: With today’s update we are also introducing filters that makes it easy to filter out types of images that you may not be interested in. The first checkbox is MSDN: using this filter you can exclude any image that is not part of the Windows Azure benefits for MSDN subscribers (which have highly discounted pricing - you can learn more about the MSDN pricing here). The second checkbox is Supported: this filter will exclude any image that contains prerelease software, so you can feel confident that the software you choose to deploy is fully supported by Windows Azure and our partners. Sort options: We sort gallery images by what we think customers are most interested in, but sometimes you might want to sort using different views. So we’re providing some additional sort options, like “Newest,” to customize the image list for what suits you best. Pricing information: We now provide additional pricing information about images and options on how to cost effectively run them directly within the VM Gallery. The above improvements make it even easier to use the VM Gallery and quickly create launch and run Virtual Machines in the cloud. Virtual Machines: ACL Support for VIPs A few months ago we exposed the ability to configure Access Control Lists (ACLs) for Virtual Machines using Windows PowerShell cmdlets and our Service Management API. With today’s release, you can now configure VM ACLs using the Windows Azure Management Portal as well. You can now do this by clicking the new Manage ACL command in the Endpoints tab of a virtual machine instance: This will enable you to configure an ordered list of permit and deny rules to scope the traffic that can access your VM’s network endpoints. For example, if you were on a virtual network, you could limit RDP access to a Windows Azure virtual machine to only a few computers attached to your enterprise. Or if you weren’t on a virtual network you could alternatively limit traffic from public IPs that can access your workloads: Here is the default behaviors for ACLs in Windows Azure: By default (i.e. no rules specified), all traffic is permitted. When using only Permit rules, all other traffic is denied. When using only Deny rules, all other traffic is permitted. When there is a combination of Permit and Deny rules, all other traffic is denied. Lastly, remember that configuring endpoints does not automatically configure them within the VM if it also has firewall rules enabled at the OS level.  So if you create an endpoint using the Windows Azure Management Portal, Windows PowerShell, or REST API, be sure to also configure your guest VM firewall appropriately as well. Web Sites: Web Sockets Support With today’s release you can now use Web Sockets with Windows Azure Web Sites.  This feature enables you to easily integrate real-time communication scenarios within your web based applications, and is available at no extra charge (it even works with the free tier).  Higher level programming libraries like SignalR and socket.io are also now supported with it. You can enable Web Sockets support on a web site by navigating to the Configure tab of a Web Site, and by toggling Web Sockets support to “on”: Once Web Sockets is enabled you can start to integrate some really cool scenarios into your web applications.  Check out the new SignalR documentation hub on www.asp.net to learn more about some of the awesome scenarios you can do with it. Web Sites: Remote Debugging Support The Windows Azure SDK 2.2 we released two weeks ago introduced remote debugging support for Windows Azure Cloud Services. With today’s Windows Azure release we are extending this remote debugging support to also work with Windows Azure Web Sites. With live, remote debugging support inside of Visual Studio, you are able to have more visibility than ever before into how your code is operating live in Windows Azure. It is now super easy to attach the debugger and quickly see what is going on with your application in the cloud. Remote Debugging of a Windows Azure Web Site using VS 2013 Enabling the remote debugging of a Windows Azure Web Site using VS 2013 is really easy.  Start by opening up your web application’s project within Visual Studio. Then navigate to the “Server Explorer” tab within Visual Studio, and click on the deployed web-site you want to debug that is running within Windows Azure using the Windows Azure->Web Sites node in the Server Explorer.  Then right-click and choose the “Attach Debugger” option on it: When you do this Visual Studio will remotely attach the debugger to the Web Site running within Windows Azure.  The debugger will then stop the web site’s execution when it hits any break points that you have set within your web application’s project inside Visual Studio.  For example, below I set a breakpoint on the “ViewBag.Message” assignment statement within the HomeController of the standard ASP.NET MVC project template.  When I hit refresh on the “About” page of the web site within the browser, the breakpoint was triggered and I am now able to debug the app remotely using Visual Studio: Note above how we can debug variables (including autos/watchlist/etc), as well as use the Immediate and Command Windows. In the debug session above I used the Immediate Window to explore some of the request object state, as well as to dynamically change the ViewBag.Message property.  When we click the the “Continue” button (or press F5) the app will continue execution and the Web Site will render the content back to the browser.  This makes it super easy to debug web apps remotely. Tips for Better Debugging To get the best experience while debugging, we recommend publishing your site using the Debug configuration within Visual Studio’s Web Publish dialog. This will ensure that debug symbol information is uploaded to the Web Site which will enable a richer debug experience within Visual Studio.  You can find this option on the Web Publish dialog on the Settings tab: When you ultimately deploy/run the application in production we recommend using the “Release” configuration setting – the release configuration is memory optimized and will provide the best production performance.  To learn more about diagnosing and debugging Windows Azure Web Sites read our new Troubleshooting Windows Azure Web Sites in Visual Studio guide. Notification Hubs: Segmented Push Notification support with tag expressions In August we announced the General Availability of Windows Azure Notification Hubs - a powerful Mobile Push Notifications service that makes it easy to send high volume push notifications with low latency from any mobile app back-end.  Notification hubs can be used with any mobile app back-end (including ones built using our Mobile Services capability) and can also be used with back-ends that run in the cloud as well as on-premises. Beginning with the initial release, Notification Hubs allowed developers to send personalized push notifications to both individual users as well as groups of users by interest, by associating their devices with tags representing the logical target of the notification. For example, by registering all devices of customers interested in a favorite MLB team with a corresponding tag, it is possible to broadcast one message to millions of Boston Red Sox fans and another message to millions of St. Louis Cardinals fans with a single API call respectively. New support for using tag expressions to enable advanced customer segmentation With today’s release we are adding support for even more advanced customer targeting.  You can now identify customers that you want to send push notifications to by defining rich tag expressions. With tag expressions, you can now not only broadcast notifications to Boston Red Sox fans, but take that segmenting a step farther and reach more granular segments. This opens up a variety of scenarios, for example: Offers based on multiple preferences—e.g. send a game day vegetarian special to users tagged as both a Boston Red Sox fan AND a vegetarian Push content to multiple segments in a single message—e.g. rain delay information only to users who are tagged as either a Boston Red Sox fan OR a St. Louis Cardinal fan Avoid presenting subsets of a segment with irrelevant content—e.g. season ticket availability reminder to users who are tagged as a Boston Red Sox fan but NOT also a season ticket holder To illustrate with code, consider a restaurant chain app that sends an offer related to a Red Sox vs Cardinals game for users in Boston. Devices can be tagged by your app with location tags (e.g. “Loc:Boston”) and interest tags (e.g. “Follows:RedSox”, “Follows:Cardinals”), and then a notification can be sent by your back-end to “(Follows:RedSox || Follows:Cardinals) && Loc:Boston” in order to deliver an offer to all devices in Boston that follow either the RedSox or the Cardinals. This can be done directly in your server backend send logic using the code below: var notification = new WindowsNotification(messagePayload); hub.SendNotificationAsync(notification, "(Follows:RedSox || Follows:Cardinals) && Loc:Boston"); In your expressions you can use all Boolean operators: AND (&&), OR (||), and NOT (!).  Some other cool use cases for tag expressions that are now supported include: Social: To “all my group except me” - group:id && !user:id Events: Touchdown event is sent to everybody following either team or any of the players involved in the action: Followteam:A || Followteam:B || followplayer:1 || followplayer:2 … Hours: Send notifications at specific times. E.g. Tag devices with time zone and when it is 12pm in Seattle send to: GMT8 && follows:thaifood Versions and platforms: Send a reminder to people still using your first version for Android - version:1.0 && platform:Android For help on getting started with Notification Hubs, visit the Notification Hub documentation center.  Then download the latest NuGet package (or use the Notification Hubs REST APIs directly) to start sending push notifications using tag expressions.  They are really powerful and enable a bunch of great new scenarios. TFS & GIT: Continuous Delivery Support for Web Sites + Cloud Services With today’s Windows Azure release we are making it really easy to enable continuous delivery support with Windows Azure and Team Foundation Services.  Team Foundation Services is a cloud based offering from Microsoft that provides integrated source control (with both TFS and Git support), build server, test execution, collaboration tools, and agile planning support.  It makes it really easy to setup a team project (complete with automated builds and test runners) in the cloud, and it has really rich integration with Visual Studio. With today’s Windows Azure release it is now really easy to enable continuous delivery support with both TFS and Git based repositories hosted using Team Foundation Services.  This enables a workflow where when code is checked in, built successfully on an automated build server, and all tests pass on it – I can automatically have the app deployed on Windows Azure with zero manual intervention or work required. The below screen-shots demonstrate how to quickly setup a continuous delivery workflow to Windows Azure with a Git-based ASP.NET MVC project hosted using Team Foundation Services. Enabling Continuous Delivery to Windows Azure with Team Foundation Services The project I’m going to enable continuous delivery with is a simple ASP.NET MVC project whose source code I’m hosting using Team Foundation Services.  I did this by creating a “SimpleContinuousDeploymentTest” repository there using Git – and then used the new built-in Git tooling support within Visual Studio 2013 to push the source code to it.  Below is a screen-shot of the Git repository hosted within Team Foundation Services: I can access the repository within Visual Studio 2013 and easily make commits with it (as well as branch, merge and do other tasks).  Using VS 2013 I can also setup automated builds to take place in the cloud using Team Foundation Services every time someone checks in code to the repository: The cool thing about this is that I don’t have to buy or rent my own build server – Team Foundation Services automatically maintains its own build server farm and can automatically queue up a build for me (for free) every time someone checks in code using the above settings.  This build server (and automated testing) support now works with both TFS and Git based source control repositories. Connecting a Team Foundation Services project to Windows Azure Once I have a source repository hosted in Team Foundation Services with Automated Builds and Testing set up, I can then go even further and set it up so that it will be automatically deployed to Windows Azure when a source code commit is made to the repository (assuming the Build + Tests pass).  Enabling this is now really easy.  To set this up with a Windows Azure Web Site simply use the New->Compute->Web Site->Custom Create command inside the Windows Azure Management Portal.  This will create a dialog like below.  I gave the web site a name and then made sure the “Publish from source control” checkbox was selected: When we click next we’ll be prompted for the location of the source repository.  We’ll select “Team Foundation Services”: Once we do this we’ll be prompted for our Team Foundation Services account that our source repository is hosted under (in this case my TFS account is “scottguthrie”): When we click the “Authorize Now” button we’ll be prompted to give Windows Azure permissions to connect to the Team Foundation Services account.  Once we do this we’ll be prompted to pick the source repository we want to connect to.  Starting with today’s Windows Azure release you can now connect to both TFS and Git based source repositories.  This new support allows me to connect to the “SimpleContinuousDeploymentTest” respository we created earlier: Clicking the finish button will then create the Web Site with the continuous delivery hooks setup with Team Foundation Services.  Now every time someone pushes source control to the repository in Team Foundation Services, it will kick off an automated build, run all of the unit tests in the solution , and if they pass the app will be automatically deployed to our Web Site in Windows Azure.  You can monitor the history and status of these automated deployments using the Deployments tab within the Web Site: This enables a really slick continuous delivery workflow, and enables you to build and deploy apps in a really nice way. Developer Analytics: New Relic support for Web Sites + Mobile Services With today’s Windows Azure release we are making it really easy to enable Developer Analytics and Monitoring support with both Windows Azure Web Site and Windows Azure Mobile Services.  We are partnering with New Relic, who provide a great dev analytics and app performance monitoring offering, to enable this - and we have updated the Windows Azure Management Portal to make it really easy to configure. Enabling New Relic with a Windows Azure Web Site Enabling New Relic support with a Windows Azure Web Site is now really easy.  Simply navigate to the Configure tab of a Web Site and scroll down to the “developer analytics” section that is now within it: Clicking the “add-on” button will display some additional UI.  If you don’t already have a New Relic subscription, you can click the “view windows azure store” button to obtain a subscription (note: New Relic has a perpetually free tier so you can enable it even without paying anything): Clicking the “view windows azure store” button will launch the integrated Windows Azure Store experience we have within the Windows Azure Management Portal.  You can use this to browse from a variety of great add-on services – including New Relic: Select “New Relic” within the dialog above, then click the next button, and you’ll be able to choose which type of New Relic subscription you wish to purchase.  For this demo we’ll simply select the “Free Standard Version” – which does not cost anything and can be used forever:  Once we’ve signed-up for our New Relic subscription and added it to our Windows Azure account, we can go back to the Web Site’s configuration tab and choose to use the New Relic add-on with our Windows Azure Web Site.  We can do this by simply selecting it from the “add-on” dropdown (it is automatically populated within it once we have a New Relic subscription in our account): Clicking the “Save” button will then cause the Windows Azure Management Portal to automatically populate all of the needed New Relic configuration settings to our Web Site: Deploying the New Relic Agent as part of a Web Site The final step to enable developer analytics using New Relic is to add the New Relic runtime agent to our web app.  We can do this within Visual Studio by right-clicking on our web project and selecting the “Manage NuGet Packages” context menu: This will bring up the NuGet package manager.  You can search for “New Relic” within it to find the New Relic agent.  Note that there is both a 32-bit and 64-bit edition of it – make sure to install the version that matches how your Web Site is running within Windows Azure (note: you can configure your Web Site to run in either 32-bit or 64-bit mode using the Web Site’s “Configuration” tab within the Windows Azure Management Portal): Once we install the NuGet package we are all set to go.  We’ll simply re-publish the web site again to Windows Azure and New Relic will now automatically start monitoring the application Monitoring a Web Site using New Relic Now that the application has developer analytics support with New Relic enabled, we can launch the New Relic monitoring portal to start monitoring the health of it.  We can do this by clicking on the “Add Ons” tab in the left-hand side of the Windows Azure Management Portal.  Then select the New Relic add-on we signed-up for within it.  The Windows Azure Management Portal will provide some default information about the add-on when we do this.  Clicking the “Manage” button in the tray at the bottom will launch a new browser tab and single-sign us into the New Relic monitoring portal associated with our account: When we do this a new browser tab will launch with the New Relic admin tool loaded within it: We can now see insights into how our app is performing – without having to have written a single line of monitoring code.  The New Relic service provides a ton of great built-in monitoring features allowing us to quickly see: Performance times (including browser rendering speed) for the overall site and individual pages.  You can optionally set alert thresholds to trigger if the speed does not meet a threshold you specify. Information about where in the world your customers are hitting the site from (and how performance varies by region) Details on the latency performance of external services your web apps are using (for example: SQL, Storage, Twitter, etc) Error information including call stack details for exceptions that have occurred at runtime SQL Server profiling information – including which queries executed against your database and what their performance was And a whole bunch more… The cool thing about New Relic is that you don’t need to write monitoring code within your application to get all of the above reports (plus a lot more).  The New Relic agent automatically enables the CLR profiler within applications and automatically captures the information necessary to identify these.  This makes it super easy to get started and immediately have a rich developer analytics view for your solutions with very little effort. If you haven’t tried New Relic out yet with Windows Azure I recommend you do so – I think you’ll find it helps you build even better cloud applications.  Following the above steps will help you get started and deliver you a really good application monitoring solution in only minutes. Service Bus: Support for partitioned queues and topics With today’s release, we are enabling support within Service Bus for partitioned queues and topics. Enabling partitioning enables you to achieve a higher message throughput and better availability from your queues and topics. Higher message throughput is achieved by implementing multiple message brokers for each partitioned queue and topic.  The  multiple messaging stores will also provide higher availability. You can create a partitioned queue or topic by simply checking the Enable Partitioning option in the custom create wizard for a Queue or Topic: Read this article to learn more about partitioned queues and topics and how to take advantage of them today. Billing: New Billing Alert Service Today’s Windows Azure update enables a new Billing Alert Service Preview that enables you to get proactive email notifications when your Windows Azure bill goes above a certain monetary threshold that you configure.  This makes it easier to manage your bill and avoid potential surprises at the end of the month. With the Billing Alert Service Preview, you can now create email alerts to monitor and manage your monetary credits or your current bill total.  To set up an alert first sign-up for the free Billing Alert Service Preview.  Then visit the account management page, click on a subscription you have setup, and then navigate to the new Alerts tab that is available: The alerts tab allows you to setup email alerts that will be sent automatically once a certain threshold is hit.  For example, by clicking the “add alert” button above I can setup a rule to send myself email anytime my Windows Azure bill goes above $100 for the month: The Billing Alert Service will evolve to support additional aspects of your bill as well as support multiple forms of alerts such as SMS.  Try out the new Billing Alert Service Preview today and give us feedback. Summary Today’s Windows Azure release enables a ton of great new scenarios, and makes building applications hosted in the cloud even easier. If you don’t already have a Windows Azure account, you can sign-up for a free trial and start using all of the above features today.  Then visit the Windows Azure Developer Center to learn more about how to build apps with it. Hope this helps, Scott P.S. In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu

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• value types in the vm

  - by john.rose

  value types in the vm p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times} p.p2 {margin: 0.0px 0.0px 14.0px 0.0px; font: 14.0px Times} p.p3 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times} p.p4 {margin: 0.0px 0.0px 15.0px 0.0px; font: 14.0px Times} p.p5 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Courier} p.p6 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Courier; min-height: 17.0px} p.p7 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times; min-height: 18.0px} p.p8 {margin: 0.0px 0.0px 0.0px 36.0px; text-indent: -36.0px; font: 14.0px Times; min-height: 18.0px} p.p9 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times; min-height: 18.0px} p.p10 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times; color: #000000} li.li1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times} li.li7 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times; min-height: 18.0px} span.s1 {font: 14.0px Courier} span.s2 {color: #000000} span.s3 {font: 14.0px Courier; color: #000000} ol.ol1 {list-style-type: decimal} Or, enduring values for a changing world. Introduction A value type is a data type which, generally speaking, is designed for being passed by value in and out of methods, and stored by value in data structures. The only value types which the Java language directly supports are the eight primitive types. Java indirectly and approximately supports value types, if they are implemented in terms of classes. For example, both Integer and String may be viewed as value types, especially if their usage is restricted to avoid operations appropriate to Object. In this note, we propose a definition of value types in terms of a design pattern for Java classes, accompanied by a set of usage restrictions. We also sketch the relation of such value types to tuple types (which are a JVM-level notion), and point out JVM optimizations that can apply to value types. This note is a thought experiment to extend the JVM’s performance model in support of value types. The demonstration has two phases.  Initially the extension can simply use design patterns, within the current bytecode architecture, and in today’s Java language. But if the performance model is to be realized in practice, it will probably require new JVM bytecode features, changes to the Java language, or both.  We will look at a few possibilities for these new features. An Axiom of Value In the context of the JVM, a value type is a data type equipped with construction, assignment, and equality operations, and a set of typed components, such that, whenever two variables of the value type produce equal corresponding values for their components, the values of the two variables cannot be distinguished by any JVM operation. Here are some corollaries: A value type is immutable, since otherwise a copy could be constructed and the original could be modified in one of its components, allowing the copies to be distinguished. Changing the component of a value type requires construction of a new value. The equals and hashCode operations are strictly component-wise. If a value type is represented by a JVM reference, that reference cannot be successfully synchronized on, and cannot be usefully compared for reference equality. A value type can be viewed in terms of what it doesn’t do. We can say that a value type omits all value-unsafe operations, which could violate the constraints on value types.  These operations, which are ordinarily allowed for Java object types, are pointer equality comparison (the acmp instruction), synchronization (the monitor instructions), all the wait and notify methods of class Object, and non-trivial finalize methods. The clone method is also value-unsafe, although for value types it could be treated as the identity function. Finally, and most importantly, any side effect on an object (however visible) also counts as an value-unsafe operation. A value type may have methods, but such methods must not change the components of the value. It is reasonable and useful to define methods like toString, equals, and hashCode on value types, and also methods which are specifically valuable to users of the value type. Representations of Value Value types have two natural representations in the JVM, unboxed and boxed. An unboxed value consists of the components, as simple variables. For example, the complex number x=(1+2i), in rectangular coordinate form, may be represented in unboxed form by the following pair of variables: /*Complex x = Complex.valueOf(1.0, 2.0):*/ double x_re = 1.0, x_im = 2.0; These variables might be locals, parameters, or fields. Their association as components of a single value is not defined to the JVM. Here is a sample computation which computes the norm of the difference between two complex numbers: double distance(/*Complex x:*/ double x_re, double x_im,         /*Complex y:*/ double y_re, double y_im) {     /*Complex z = x.minus(y):*/     double z_re = x_re - y_re, z_im = x_im - y_im;     /*return z.abs():*/     return Math.sqrt(z_re*z_re + z_im*z_im); } A boxed representation groups component values under a single object reference. The reference is to a ‘wrapper class’ that carries the component values in its fields. (A primitive type can naturally be equated with a trivial value type with just one component of that type. In that view, the wrapper class Integer can serve as a boxed representation of value type int.) The unboxed representation of complex numbers is practical for many uses, but it fails to cover several major use cases: return values, array elements, and generic APIs. The two components of a complex number cannot be directly returned from a Java function, since Java does not support multiple return values. The same story applies to array elements: Java has no ’array of structs’ feature. (Double-length arrays are a possible workaround for complex numbers, but not for value types with heterogeneous components.) By generic APIs I mean both those which use generic types, like Arrays.asList and those which have special case support for primitive types, like String.valueOf and PrintStream.println. Those APIs do not support unboxed values, and offer some problems to boxed values. Any ’real’ JVM type should have a story for returns, arrays, and API interoperability. The basic problem here is that value types fall between primitive types and object types. Value types are clearly more complex than primitive types, and object types are slightly too complicated. Objects are a little bit dangerous to use as value carriers, since object references can be compared for pointer equality, and can be synchronized on. Also, as many Java programmers have observed, there is often a performance cost to using wrapper objects, even on modern JVMs. Even so, wrapper classes are a good starting point for talking about value types. If there were a set of structural rules and restrictions which would prevent value-unsafe operations on value types, wrapper classes would provide a good notation for defining value types. This note attempts to define such rules and restrictions. Let’s Start Coding Now it is time to look at some real code. Here is a definition, written in Java, of a complex number value type. @ValueSafe public final class Complex implements java.io.Serializable {     // immutable component structure:     public final double re, im;     private Complex(double re, double im) {         this.re = re; this.im = im;     }     // interoperability methods:     public String toString() { return "Complex("+re+","+im+")"; }     public List<Double> asList() { return Arrays.asList(re, im); }     public boolean equals(Complex c) {         return re == c.re && im == c.im;     }     public boolean equals(@ValueSafe Object x) {         return x instanceof Complex && equals((Complex) x);     }     public int hashCode() {         return 31*Double.valueOf(re).hashCode()                 + Double.valueOf(im).hashCode();     }     // factory methods:     public static Complex valueOf(double re, double im) {         return new Complex(re, im);     }     public Complex changeRe(double re2) { return valueOf(re2, im); }     public Complex changeIm(double im2) { return valueOf(re, im2); }     public static Complex cast(@ValueSafe Object x) {         return x == null ? ZERO : (Complex) x;     }     // utility methods and constants:     public Complex plus(Complex c)  { return new Complex(re+c.re, im+c.im); }     public Complex minus(Complex c) { return new Complex(re-c.re, im-c.im); }     public double abs() { return Math.sqrt(re*re + im*im); }     public static final Complex PI = valueOf(Math.PI, 0.0);     public static final Complex ZERO = valueOf(0.0, 0.0); } This is not a minimal definition, because it includes some utility methods and other optional parts.  The essential elements are as follows: The class is marked as a value type with an annotation. The class is final, because it does not make sense to create subclasses of value types. The fields of the class are all non-private and final.  (I.e., the type is immutable and structurally transparent.) From the supertype Object, all public non-final methods are overridden. The constructor is private. Beyond these bare essentials, we can observe the following features in this example, which are likely to be typical of all value types: One or more factory methods are responsible for value creation, including a component-wise valueOf method. There are utility methods for complex arithmetic and instance creation, such as plus and changeIm. There are static utility constants, such as PI. The type is serializable, using the default mechanisms. There are methods for converting to and from dynamically typed references, such as asList and cast. The Rules In order to use value types properly, the programmer must avoid value-unsafe operations.  A helpful Java compiler should issue errors (or at least warnings) for code which provably applies value-unsafe operations, and should issue warnings for code which might be correct but does not provably avoid value-unsafe operations.  No such compilers exist today, but to simplify our account here, we will pretend that they do exist. A value-safe type is any class, interface, or type parameter marked with the @ValueSafe annotation, or any subtype of a value-safe type.  If a value-safe class is marked final, it is in fact a value type.  All other value-safe classes must be abstract.  The non-static fields of a value class must be non-public and final, and all its constructors must be private. Under the above rules, a standard interface could be helpful to define value types like Complex.  Here is an example: @ValueSafe public interface ValueType extends java.io.Serializable {     // All methods listed here must get redefined.     // Definitions must be value-safe, which means     // they may depend on component values only.     List<? extends Object> asList();     int hashCode();     boolean equals(@ValueSafe Object c);     String toString(); } //@ValueSafe inherited from supertype: public final class Complex implements ValueType { … The main advantage of such a conventional interface is that (unlike an annotation) it is reified in the runtime type system.  It could appear as an element type or parameter bound, for facilities which are designed to work on value types only.  More broadly, it might assist the JVM to perform dynamic enforcement of the rules for value types. Besides types, the annotation @ValueSafe can mark fields, parameters, local variables, and methods.  (This is redundant when the type is also value-safe, but may be useful when the type is Object or another supertype of a value type.)  Working forward from these annotations, an expression E is defined as value-safe if it satisfies one or more of the following: The type of E is a value-safe type. E names a field, parameter, or local variable whose declaration is marked @ValueSafe. E is a call to a method whose declaration is marked @ValueSafe. E is an assignment to a value-safe variable, field reference, or array reference. E is a cast to a value-safe type from a value-safe expression. E is a conditional expression E0 ? E1 : E2, and both E1 and E2 are value-safe. Assignments to value-safe expressions and initializations of value-safe names must take their values from value-safe expressions. A value-safe expression may not be the subject of a value-unsafe operation.  In particular, it cannot be synchronized on, nor can it be compared with the “==” operator, not even with a null or with another value-safe type. In a program where all of these rules are followed, no value-type value will be subject to a value-unsafe operation.  Thus, the prime axiom of value types will be satisfied, that no two value type will be distinguishable as long as their component values are equal. More Code To illustrate these rules, here are some usage examples for Complex: Complex pi = Complex.valueOf(Math.PI, 0); Complex zero = pi.changeRe(0);  //zero = pi; zero.re = 0; ValueType vtype = pi; @SuppressWarnings("value-unsafe")   Object obj = pi; @ValueSafe Object obj2 = pi; obj2 = new Object();  // ok List<Complex> clist = new ArrayList<Complex>(); clist.add(pi);  // (ok assuming List.add param is @ValueSafe) List<ValueType> vlist = new ArrayList<ValueType>(); vlist.add(pi);  // (ok) List<Object> olist = new ArrayList<Object>(); olist.add(pi);  // warning: "value-unsafe" boolean z = pi.equals(zero); boolean z1 = (pi == zero);  // error: reference comparison on value type boolean z2 = (pi == null);  // error: reference comparison on value type boolean z3 = (pi == obj2);  // error: reference comparison on value type synchronized (pi) { }  // error: synch of value, unpredictable result synchronized (obj2) { }  // unpredictable result Complex qq = pi; qq = null;  // possible NPE; warning: “null-unsafe" qq = (Complex) obj;  // warning: “null-unsafe" qq = Complex.cast(obj);  // OK @SuppressWarnings("null-unsafe")   Complex empty = null;  // possible NPE qq = empty;  // possible NPE (null pollution) The Payoffs It follows from this that either the JVM or the java compiler can replace boxed value-type values with unboxed ones, without affecting normal computations.  Fields and variables of value types can be split into their unboxed components.  Non-static methods on value types can be transformed into static methods which take the components as value parameters. Some common questions arise around this point in any discussion of value types. Why burden the programmer with all these extra rules?  Why not detect programs automagically and perform unboxing transparently?  The answer is that it is easy to break the rules accidently unless they are agreed to by the programmer and enforced.  Automatic unboxing optimizations are tantalizing but (so far) unreachable ideal.  In the current state of the art, it is possible exhibit benchmarks in which automatic unboxing provides the desired effects, but it is not possible to provide a JVM with a performance model that assures the programmer when unboxing will occur.  This is why I’m writing this note, to enlist help from, and provide assurances to, the programmer.  Basically, I’m shooting for a good set of user-supplied “pragmas” to frame the desired optimization. Again, the important thing is that the unboxing must be done reliably, or else programmers will have no reason to work with the extra complexity of the value-safety rules.  There must be a reasonably stable performance model, wherein using a value type has approximately the same performance characteristics as writing the unboxed components as separate Java variables. There are some rough corners to the present scheme.  Since Java fields and array elements are initialized to null, value-type computations which incorporate uninitialized variables can produce null pointer exceptions.  One workaround for this is to require such variables to be null-tested, and the result replaced with a suitable all-zero value of the value type.  That is what the “cast” method does above. Generically typed APIs like List<T> will continue to manipulate boxed values always, at least until we figure out how to do reification of generic type instances.  Use of such APIs will elicit warnings until their type parameters (and/or relevant members) are annotated or typed as value-safe.  Retrofitting List<T> is likely to expose flaws in the present scheme, which we will need to engineer around.  Here are a couple of first approaches: public interface java.util.List<@ValueSafe T> extends Collection<T> { … public interface java.util.List<T extends Object|ValueType> extends Collection<T> { … (The second approach would require disjunctive types, in which value-safety is “contagious” from the constituent types.) With more transformations, the return value types of methods can also be unboxed.  This may require significant bytecode-level transformations, and would work best in the presence of a bytecode representation for multiple value groups, which I have proposed elsewhere under the title “Tuples in the VM”. But for starters, the JVM can apply this transformation under the covers, to internally compiled methods.  This would give a way to express multiple return values and structured return values, which is a significant pain-point for Java programmers, especially those who work with low-level structure types favored by modern vector and graphics processors.  The lack of multiple return values has a strong distorting effect on many Java APIs. Even if the JVM fails to unbox a value, there is still potential benefit to the value type.  Clustered computing systems something have copy operations (serialization or something similar) which apply implicitly to command operands.  When copying JVM objects, it is extremely helpful to know when an object’s identity is important or not.  If an object reference is a copied operand, the system may have to create a proxy handle which points back to the original object, so that side effects are visible.  Proxies must be managed carefully, and this can be expensive.  On the other hand, value types are exactly those types which a JVM can “copy and forget” with no downside. Array types are crucial to bulk data interfaces.  (As data sizes and rates increase, bulk data becomes more important than scalar data, so arrays are definitely accompanying us into the future of computing.)  Value types are very helpful for adding structure to bulk data, so a successful value type mechanism will make it easier for us to express richer forms of bulk data. Unboxing arrays (i.e., arrays containing unboxed values) will provide better cache and memory density, and more direct data movement within clustered or heterogeneous computing systems.  They require the deepest transformations, relative to today’s JVM.  There is an impedance mismatch between value-type arrays and Java’s covariant array typing, so compromises will need to be struck with existing Java semantics.  It is probably worth the effort, since arrays of unboxed value types are inherently more memory-efficient than standard Java arrays, which rely on dependent pointer chains. It may be sufficient to extend the “value-safe” concept to array declarations, and allow low-level transformations to change value-safe array declarations from the standard boxed form into an unboxed tuple-based form.  Such value-safe arrays would not be convertible to Object[] arrays.  Certain connection points, such as Arrays.copyOf and System.arraycopy might need additional input/output combinations, to allow smooth conversion between arrays with boxed and unboxed elements. Alternatively, the correct solution may have to wait until we have enough reification of generic types, and enough operator overloading, to enable an overhaul of Java arrays. Implicit Method Definitions The example of class Complex above may be unattractively complex.  I believe most or all of the elements of the example class are required by the logic of value types. If this is true, a programmer who writes a value type will have to write lots of error-prone boilerplate code.  On the other hand, I think nearly all of the code (except for the domain-specific parts like plus and minus) can be implicitly generated. Java has a rule for implicitly defining a class’s constructor, if no it defines no constructors explicitly.  Likewise, there are rules for providing default access modifiers for interface members.  Because of the highly regular structure of value types, it might be reasonable to perform similar implicit transformations on value types.  Here’s an example of a “highly implicit” definition of a complex number type: public class Complex implements ValueType {  // implicitly final     public double re, im;  // implicitly public final     //implicit methods are defined elementwise from te fields:     //  toString, asList, equals(2), hashCode, valueOf, cast     //optionally, explicit methods (plus, abs, etc.) would go here } In other words, with the right defaults, a simple value type definition can be a one-liner.  The observant reader will have noticed the similarities (and suitable differences) between the explicit methods above and the corresponding methods for List<T>. Another way to abbreviate such a class would be to make an annotation the primary trigger of the functionality, and to add the interface(s) implicitly: public @ValueType class Complex { … // implicitly final, implements ValueType (But to me it seems better to communicate the “magic” via an interface, even if it is rooted in an annotation.) Implicitly Defined Value Types So far we have been working with nominal value types, which is to say that the sequence of typed components is associated with a name and additional methods that convey the intention of the programmer.  A simple ordered pair of floating point numbers can be variously interpreted as (to name a few possibilities) a rectangular or polar complex number or Cartesian point.  The name and the methods convey the intended meaning. But what if we need a truly simple ordered pair of floating point numbers, without any further conceptual baggage?  Perhaps we are writing a method (like “divideAndRemainder”) which naturally returns a pair of numbers instead of a single number.  Wrapping the pair of numbers in a nominal type (like “QuotientAndRemainder”) makes as little sense as wrapping a single return value in a nominal type (like “Quotient”).  What we need here are structural value types commonly known as tuples. For the present discussion, let us assign a conventional, JVM-friendly name to tuples, roughly as follows: public class java.lang.tuple.$DD extends java.lang.tuple.Tuple {      double $1, $2; } Here the component names are fixed and all the required methods are defined implicitly.  The supertype is an abstract class which has suitable shared declarations.  The name itself mentions a JVM-style method parameter descriptor, which may be “cracked” to determine the number and types of the component fields. The odd thing about such a tuple type (and structural types in general) is it must be instantiated lazily, in response to linkage requests from one or more classes that need it.  The JVM and/or its class loaders must be prepared to spin a tuple type on demand, given a simple name reference, $xyz, where the xyz is cracked into a series of component types.  (Specifics of naming and name mangling need some tasteful engineering.) Tuples also seem to demand, even more than nominal types, some support from the language.  (This is probably because notations for non-nominal types work best as combinations of punctuation and type names, rather than named constructors like Function3 or Tuple2.)  At a minimum, languages with tuples usually (I think) have some sort of simple bracket notation for creating tuples, and a corresponding pattern-matching syntax (or “destructuring bind”) for taking tuples apart, at least when they are parameter lists.  Designing such a syntax is no simple thing, because it ought to play well with nominal value types, and also with pre-existing Java features, such as method parameter lists, implicit conversions, generic types, and reflection.  That is a task for another day. Other Use Cases Besides complex numbers and simple tuples there are many use cases for value types.  Many tuple-like types have natural value-type representations. These include rational numbers, point locations and pixel colors, and various kinds of dates and addresses. Other types have a variable-length ‘tail’ of internal values. The most common example of this is String, which is (mathematically) a sequence of UTF-16 character values. Similarly, bit vectors, multiple-precision numbers, and polynomials are composed of sequences of values. Such types include, in their representation, a reference to a variable-sized data structure (often an array) which (somehow) represents the sequence of values. The value type may also include ’header’ information. Variable-sized values often have a length distribution which favors short lengths. In that case, the design of the value type can make the first few values in the sequence be direct ’header’ fields of the value type. In the common case where the header is enough to represent the whole value, the tail can be a shared null value, or even just a null reference. Note that the tail need not be an immutable object, as long as the header type encapsulates it well enough. This is the case with String, where the tail is a mutable (but never mutated) character array. Field types and their order must be a globally visible part of the API.  The structure of the value type must be transparent enough to have a globally consistent unboxed representation, so that all callers and callees agree about the type and order of components  that appear as parameters, return types, and array elements.  This is a trade-off between efficiency and encapsulation, which is forced on us when we remove an indirection enjoyed by boxed representations.  A JVM-only transformation would not care about such visibility, but a bytecode transformation would need to take care that (say) the components of complex numbers would not get swapped after a redefinition of Complex and a partial recompile.  Perhaps constant pool references to value types need to declare the field order as assumed by each API user. This brings up the delicate status of private fields in a value type.  It must always be possible to load, store, and copy value types as coordinated groups, and the JVM performs those movements by moving individual scalar values between locals and stack.  If a component field is not public, what is to prevent hostile code from plucking it out of the tuple using a rogue aload or astore instruction?  Nothing but the verifier, so we may need to give it more smarts, so that it treats value types as inseparable groups of stack slots or locals (something like long or double). My initial thought was to make the fields always public, which would make the security problem moot.  But public is not always the right answer; consider the case of String, where the underlying mutable character array must be encapsulated to prevent security holes.  I believe we can win back both sides of the tradeoff, by training the verifier never to split up the components in an unboxed value.  Just as the verifier encapsulates the two halves of a 64-bit primitive, it can encapsulate the the header and body of an unboxed String, so that no code other than that of class String itself can take apart the values. Similar to String, we could build an efficient multi-precision decimal type along these lines: public final class DecimalValue extends ValueType {     protected final long header;     protected private final BigInteger digits;     public DecimalValue valueOf(int value, int scale) {         assert(scale >= 0);         return new DecimalValue(((long)value << 32) + scale, null);     }     public DecimalValue valueOf(long value, int scale) {         if (value == (int) value)             return valueOf((int)value, scale);         return new DecimalValue(-scale, new BigInteger(value));     } } Values of this type would be passed between methods as two machine words. Small values (those with a significand which fits into 32 bits) would be represented without any heap data at all, unless the DecimalValue itself were boxed. (Note the tension between encapsulation and unboxing in this case.  It would be better if the header and digits fields were private, but depending on where the unboxing information must “leak”, it is probably safer to make a public revelation of the internal structure.) Note that, although an array of Complex can be faked with a double-length array of double, there is no easy way to fake an array of unboxed DecimalValues.  (Either an array of boxed values or a transposed pair of homogeneous arrays would be reasonable fallbacks, in a current JVM.)  Getting the full benefit of unboxing and arrays will require some new JVM magic. Although the JVM emphasizes portability, system dependent code will benefit from using machine-level types larger than 64 bits.  For example, the back end of a linear algebra package might benefit from value types like Float4 which map to stock vector types.  This is probably only worthwhile if the unboxing arrays can be packed with such values. More Daydreams A more finely-divided design for dynamic enforcement of value safety could feature separate marker interfaces for each invariant.  An empty marker interface Unsynchronizable could cause suitable exceptions for monitor instructions on objects in marked classes.  More radically, a Interchangeable marker interface could cause JVM primitives that are sensitive to object identity to raise exceptions; the strangest result would be that the acmp instruction would have to be specified as raising an exception. @ValueSafe public interface ValueType extends java.io.Serializable,         Unsynchronizable, Interchangeable { … public class Complex implements ValueType {     // inherits Serializable, Unsynchronizable, Interchangeable, @ValueSafe     … It seems possible that Integer and the other wrapper types could be retro-fitted as value-safe types.  This is a major change, since wrapper objects would be unsynchronizable and their references interchangeable.  It is likely that code which violates value-safety for wrapper types exists but is uncommon.  It is less plausible to retro-fit String, since the prominent operation String.intern is often used with value-unsafe code. We should also reconsider the distinction between boxed and unboxed values in code.  The design presented above obscures that distinction.  As another thought experiment, we could imagine making a first class distinction in the type system between boxed and unboxed representations.  Since only primitive types are named with a lower-case initial letter, we could define that the capitalized version of a value type name always refers to the boxed representation, while the initial lower-case variant always refers to boxed.  For example: complex pi = complex.valueOf(Math.PI, 0); Complex boxPi = pi;  // convert to boxed myList.add(boxPi); complex z = myList.get(0);  // unbox Such a convention could perhaps absorb the current difference between int and Integer, double and Double. It might also allow the programmer to express a helpful distinction among array types. As said above, array types are crucial to bulk data interfaces, but are limited in the JVM.  Extending arrays beyond the present limitations is worth thinking about; for example, the Maxine JVM implementation has a hybrid object/array type.  Something like this which can also accommodate value type components seems worthwhile.  On the other hand, does it make sense for value types to contain short arrays?  And why should random-access arrays be the end of our design process, when bulk data is often sequentially accessed, and it might make sense to have heterogeneous streams of data as the natural “jumbo” data structure.  These considerations must wait for another day and another note. More Work It seems to me that a good sequence for introducing such value types would be as follows: Add the value-safety restrictions to an experimental version of javac. Code some sample applications with value types, including Complex and DecimalValue. Create an experimental JVM which internally unboxes value types but does not require new bytecodes to do so.  Ensure the feasibility of the performance model for the sample applications. Add tuple-like bytecodes (with or without generic type reification) to a major revision of the JVM, and teach the Java compiler to switch in the new bytecodes without code changes. A staggered roll-out like this would decouple language changes from bytecode changes, which is always a convenient thing. A similar investigation should be applied (concurrently) to array types.  In this case, it seems to me that the starting point is in the JVM: Add an experimental unboxing array data structure to a production JVM, perhaps along the lines of Maxine hybrids.  No bytecode or language support is required at first; everything can be done with encapsulated unsafe operations and/or method handles. Create an experimental JVM which internally unboxes value types but does not require new bytecodes to do so.  Ensure the feasibility of the performance model for the sample applications. Add tuple-like bytecodes (with or without generic type reification) to a major revision of the JVM, and teach the Java compiler to switch in the new bytecodes without code changes. That’s enough musing me for now.  Back to work!

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• iPhone SDK vs Windows Phone 7 Series SDK Challenge, Part 1: Hello World!

  In this series, I will be taking sample applications from the iPhone SDK and implementing them on Windows Phone 7 Series.  My goal is to do as much of an apples-to-apples comparison as I can.  This series will be written to not only compare and contrast how easy or difficult it is to complete tasks on either platform, how many lines of code, etc., but Id also like it to be a way for iPhone developers to either get started on Windows Phone 7 Series development, or for developers in general to learn the platform. Heres my methodology: Run the iPhone SDK app in the iPhone Simulator to get a feel for what it does and how it works, without looking at the implementation Implement the equivalent functionality on Windows Phone 7 Series using Silverlight. Compare the two implementations based on complexity, functionality, lines of code, number of files, etc. Add some functionality to the Windows Phone 7 Series app that shows off a way to make the scenario more interesting or leverages an aspect of the platform, or uses a better design pattern to implement the functionality. You can download Microsoft Visual Studio 2010 Express for Windows Phone CTP here, and the Expression Blend 4 Beta here. Hello World! Of course no first post would be allowed if it didnt focus on the hello world scenario.  The iPhone SDK follows that tradition with the Your First iPhone Application walkthrough.  I will say that the developer documentation for iPhone is pretty good.  There are plenty of walkthoughs and they break things down into nicely sized steps and do a good job of bringing the user along.  As expected, this application is quite simple.  It comprises of a text box, a label, and a button.  When you push the button, the label changes to Hello plus the  word you typed into the text box.  Makes perfect sense for a starter application.  Theres not much to this but it covers a few basic elements: Laying out basic UI Handling user input Hooking up events Formatting text     So, lets get started building a similar app for Windows Phone 7 Series! Implementing the UI: UI in Silverlight (and therefore Windows Phone 7) is defined in XAML, which is a declarative XML language also used by WPF on the desktop.  For anyone thats familiar with similar types of markup, its relatively straightforward to learn, but has a lot of power in it once you get it figured out.  Well talk more about that. This UI is very simple.  When I look at this, I note a couple of things: Elements are arranged vertically They are all centered So, lets create our Application and then start with the UI.  Once you have the the VS 2010 Express for Windows Phone tool running, create a new Windows Phone Project, and call it Hello World: Once created, youll see the designer on one side and your XAML on the other: Now, we can create our UI in one of three ways: Use the designer in Visual Studio to drag and drop the components Use the designer in Expression Blend 4 to drag and drop the components Enter the XAML by hand in either of the above Well start with (1), then kind of move to (3) just for instructional value. To develop this UI in the designer: First, delete all of the markup between inside of the Grid element (LayoutRoot).  You should be left with just this XAML for your MainPage.xaml (i shortened all the xmlns declarations below for brevity): 1: <phoneNavigation:PhoneApplicationPage 2: x:Class="HelloWorld.MainPage" 3: xmlns="...[snip]" 4: FontFamily="{StaticResource PhoneFontFamilyNormal}" 5: FontSize="{StaticResource PhoneFontSizeNormal}" 6: Foreground="{StaticResource PhoneForegroundBrush}"> 7:   8: <Grid x:Name="LayoutRoot" Background="{StaticResource PhoneBackgroundBrush}"> 9:   10: </Grid> 11:   12: </phoneNavigation:PhoneApplicationPage> .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }   Well be adding XAML at line 9, so thats the important part. Now, Click on the center area of the phone surface Open the Toolbox and double click StackPanel Double click TextBox Double click TextBlock Double click Button That will create the necessary UI elements but they wont be arranged quite right.  Well fix it in a second.    Heres the XAML that we end up with: 1: <StackPanel Height="100" HorizontalAlignment="Left" Margin="10,10,0,0" Name="stackPanel1" VerticalAlignment="Top" Width="200"> 2: <TextBox Height="32" Name="textBox1" Text="TextBox" Width="100" /> 3: <TextBlock Height="23" Name="textBlock1" Text="TextBlock" /> 4: <Button Content="Button" Height="70" Name="button1" Width="160" /> 5: </StackPanel> .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } The designer does its best at guessing what we want, but in this case we want things to be a bit simpler. So well just clean it up a bit.  We want the items to be centered and we want them to have a little bit of a margin on either side, so heres what we end up with.  Ive also made it match the values and style from the iPhone app: 1: <StackPanel Margin="10"> 2: <TextBox Name="textBox1" HorizontalAlignment="Stretch" Text="You" TextAlignment="Center"/> 3: <TextBlock Name="textBlock1" HorizontalAlignment="Center" Margin="0,100,0,0" Text="Hello You!" /> 4: <Button Name="button1" HorizontalAlignment="Center" Margin="0,150,0,0" Content="Hello"/> 5: </StackPanel> .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Now lets take a look at what weve done there. Line 1: We removed all of the formatting from the StackPanel, except for Margin, as thats all we need.  Since our parent element is a Grid, by default the StackPanel will be sized to fit in that space.  The Margin says that we want to reserve 10 pixels on each side of the StackPanel. Line 2: Weve set the HorizontalAlignment of the TextBox to Stretch, which says that it should fill its parents size horizontally.  We want to do this so the TextBox is always full-width.  We also set TextAlignment to Center, to center the text. Line 3: In contrast to the TextBox above, we dont care how wide the TextBlock is, just so long as it is big enough for its text.  Thatll happen automatically, so we just set its Horizontal alignment to Center.  We also set a Margin above the TextBlock of 100 pixels to bump it down a bit, per the iPhone UI. Line 4: We do the same things here as in Line 3. Heres how the UI looks in the designer: Believe it or not, were almost done! Implementing the App Logic Now, we want the TextBlock to change its text when the Button is clicked.  In the designer, double click the Button to be taken to the Event Handler for the Buttons Click event.  In that event handler, we take the Text property from the TextBox, and format it into a string, then set it into the TextBlock.  Thats it! 1: private void button1_Click(object sender, RoutedEventArgs e) 2: { 3: string name = textBox1.Text; 4:   5: // if there isn't a name set, just use "World" 6: if (String.IsNullOrEmpty(name)) 7: { 8: name = "World"; 9: } 10:   11: // set the value into the TextBlock 12: textBlock1.Text = String.Format("Hello {0}!", name); 13:   14: } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } We use the String.Format() method to handle the formatting for us.    Now all thats left is to test the app in the Windows Phone Emulator and verify it does what we think it does! And it does! Comparing against the iPhone Looking at the iPhone example, there are basically three things that you have to touch as the developer: 1) The UI in the Nib file 2) The app delegate 3) The view controller Counting lines is a bit tricky here, but to try to keep this even, Im going to only count lines of code that I could not have (or would not have) generated with the tooling.  Meaning, Im not counting XAML and Im not counting operations that happen in the Nib file with the XCode designer tool.  So in the case of the above, even though I modified the XAML, I could have done all of those operations using the visual designer tool.  And normally I would have, but the XAML is more instructive (and less steps!).  Im interested in things that I, as the developer have to figure out in code.  Im also not counting lines that just have a curly brace on them, or lines that are generated for me (e.g. method names that are generated for me when I make a connection, etc.) So, by that count, heres what I get from the code listing for the iPhone app found here: HelloWorldAppDelegate.h: 6 HelloWorldAppDelegate.m: 12 MyViewController.h: 8 MyViewController.m: 18 Which gives me a grand total of about 44 lines of code on iPhone.  I really do recommend looking at the iPhone code for a comparison to the above. Now, for the Windows Phone 7 Series application, the only code I typed was in the event handler above Main.Xaml.cs: 4 So a total of 4 lines of code on Windows Phone 7.  And more importantly, the process is just A LOT simpler.  For example, I was surprised that the User Interface Designer in XCode doesnt automatically create instance variables for me and wire them up to the corresponding elements.  I assumed I wouldnt have to write this code myself (and risk getting it wrong!).  I dont need to worry about view controllers or anything.  I just write my code.  This blog post up to this point has covered almost every aspect of this apps development in a few pages.  The iPhone tutorial has 5 top level steps with 2-3 sub sections of each. Now, its worth pointing out that the iPhone development model uses the Model View Controller (MVC) pattern, which is a very flexible and powerful pattern that enforces proper separation of concerns.  But its fairly complex and difficult to understand when you first walk up to it.  Here at Microsoft weve dabbled in MVC a bit, with frameworks like MFC on Visual C++ and with the ASP.NET MVC framework now.  Both are very powerful frameworks.  But one of the reasons weve stayed away from MVC with client UI frameworks is that its difficult to tool.  We havent seen the type of value that beats double click, write code! for the broad set of scenarios. Another thing to think about is how many of those lines of code were focused on my apps functionality?.  Or, the converse of How many lines of code were boilerplate plumbing?  In both examples, the actual number of functional code lines is similar.  I count most of them in MyViewController.m, in the changeGreeting method.  Its about 7 lines of code that do the work of taking the value from the TextBox and putting it into the label.  Versus 4 on the Windows Phone 7 side.  But, unfortunately, on iPhone I still have to write that other 37 lines of code, just to get there. 10% of the code, 1 file instead of 4, its just much simpler. Making Some Tweaks It turns out, I can actually do this application with ZERO  lines of code, if Im willing to change the spec a bit. The data binding functionality in Silverlight is incredibly powerful.  And what I can do is databind the TextBoxs value directly to the TextBlock.  Take some time looking at this XAML below.  Youll see that I have added another nested StackPanel and two more TextBlocks.  Why?  Because thats how I build that string, and the nested StackPanel will lay things out Horizontally for me, as specified by the Orientation property. 1: <StackPanel Margin="10"> 2: <TextBox Name="textBox1" HorizontalAlignment="Stretch" Text="You" TextAlignment="Center"/> 3: <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" Margin="0,100,0,0" > 4: <TextBlock Text="Hello " /> 5: <TextBlock Name="textBlock1" Text="{Binding ElementName=textBox1, Path=Text}" /> 6: <TextBlock Text="!" /> 7: </StackPanel> 8: <Button Name="button1" HorizontalAlignment="Center" Margin="0,150,0,0" Content="Hello" Click="button1_Click" /> 9: </StackPanel> .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Now, the real action is there in the bolded TextBlock.Text property: Text="{Binding ElementName=textBox1, Path=Text}" .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } That does all the heavy lifting.  It sets up a databinding between the TextBox.Text property on textBox1 and the TextBlock.Text property on textBlock1. As I change the text of the TextBox, the label updates automatically. In fact, I dont even need the button any more, so I could get rid of that altogether.  And no button means no event handler.  No event handler means no C# code at all.  Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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• Extending Oracle CEP with Predictive Analytics

  - by vikram.shukla(at)oracle.com

  Introduction: OCEP is often used as a business rules engine to execute a set of business logic rules via CQL statements, and take decisions based on the outcome of those rules. There are times where configuring rules manually is sufficient because an application needs to deal with only a small and well-defined set of static rules. However, in many situations customers don't want to pre-define such rules for two reasons. First, they are dealing with events with lots of columns and manually crafting such rules for each column or a set of columns and combinations thereof is almost impossible. Second, they are content with probabilistic outcomes and do not care about 100% precision. The former is the case when a user is dealing with data with high dimensionality, the latter when an application can live with "false" positives as they can be discarded after further inspection, say by a Human Task component in a Business Process Management software. The primary goal of this blog post is to show how this can be achieved by combining OCEP with Oracle Data Mining® and leveraging the latter's rich set of algorithms and functionality to do predictive analytics in real time on streaming events. The secondary goal of this post is also to show how OCEP can be extended to invoke any arbitrary external computation in an RDBMS from within CEP. The extensible facility is known as the JDBC cartridge. The rest of the post describes the steps required to achieve this: We use the dataset available at http://blogs.oracle.com/datamining/2010/01/fraud_and_anomaly_detection_made_simple.html to showcase the capabilities. We use it to show how transaction anomalies or fraud can be detected. Building the model: Follow the self-explanatory steps described at the above URL to build the model.  It is very simple - it uses built-in Oracle Data Mining PL/SQL packages to cleanse, normalize and build the model out of the dataset.  You can also use graphical Oracle Data Miner®  to build the models. To summarize, it involves: Specifying which algorithms to use. In this case we use Support Vector Machines as we're trying to find anomalies in highly dimensional dataset.Build model on the data in the table for the algorithms specified. For this example, the table was populated in the scott/tiger schema with appropriate privileges. Configuring the Data Source: This is the first step in building CEP application using such an integration.  Our datasource looks as follows in the server config file.  It is advisable that you use the Visualizer to add it to the running server dynamically, rather than manually edit the file.    <data-source>         <name>DataMining</name>         <data-source-params>             <jndi-names>                 <element>DataMining</element>             </jndi-names>             <global-transactions-protocol>OnePhaseCommit</global-transactions-protocol>         </data-source-params>         <connection-pool-params>             <credential-mapping-enabled></credential-mapping-enabled>             <test-table-name>SQL SELECT 1 from DUAL</test-table-name>             <initial-capacity>1</initial-capacity>             <max-capacity>15</max-capacity>             <capacity-increment>1</capacity-increment>         </connection-pool-params>         <driver-params>             <use-xa-data-source-interface>true</use-xa-data-source-interface>             <driver-name>oracle.jdbc.OracleDriver</driver-name>             <url>jdbc:oracle:thin:@localhost:1522:orcl</url>             <properties>                 <element>                     <value>scott</value>                     <name>user</name>                 </element>                 <element>                     <value>{Salted-3DES}AzFE5dDbO2g=</value>                     <name>password</name>                 </element>                                 <element>                     <name>com.bea.core.datasource.serviceName</name>                     <value>oracle11.2g</value>                 </element>                 <element>                     <name>com.bea.core.datasource.serviceVersion</name>                     <value>11.2.0</value>                 </element>                 <element>                     <name>com.bea.core.datasource.serviceObjectClass</name>                     <value>java.sql.Driver</value>                 </element>             </properties>         </driver-params>     </data-source>   Designing the EPN: The EPN is very simple in this example. We briefly describe each of the components. The adapter ("DataMiningAdapter") reads data from a .csv file and sends it to the CQL processor downstream. The event payload here is same as that of the table in the database (refer to the attached project or do a "desc table-name" from a SQL*PLUS prompt). While this is for convenience in this example, it need not be the case. One can still omit fields in the streaming events, and need not match all columns in the table on which the model was built. Better yet, it does not even need to have the same name as columns in the table, as long as you alias them in the USING clause of the mining function. (Caveat: they still need to draw values from a similar universe or domain, otherwise it constitutes incorrect usage of the model). There are two things in the CQL processor ("DataMiningProc") that make scoring possible on streaming events. 1.      User defined cartridge function Please refer to the OCEP CQL reference manual to find more details about how to define such functions. We include the function below in its entirety for illustration. <?xml version="1.0" encoding="UTF-8"?> <jdbcctxconfig:config     xmlns:jdbcctxconfig="http://www.bea.com/ns/wlevs/config/application"     xmlns:jc="http://www.oracle.com/ns/ocep/config/jdbc">        <jc:jdbc-ctx>         <name>Oracle11gR2</name>         <data-source>DataMining</data-source>               <function name="prediction2">                                 <param name="CQLMONTH" type="char"/>                      <param name="WEEKOFMONTH" type="int"/>                      <param name="DAYOFWEEK" type="char" />                      <param name="MAKE" type="char" />                      <param name="ACCIDENTAREA"   type="char" />                      <param name="DAYOFWEEKCLAIMED"  type="char" />                      <param name="MONTHCLAIMED" type="char" />                      <param name="WEEKOFMONTHCLAIMED" type="int" />                      <param name="SEX" type="char" />                      <param name="MARITALSTATUS"   type="char" />                      <param name="AGE" type="int" />                      <param name="FAULT" type="char" />                      <param name="POLICYTYPE"   type="char" />                      <param name="VEHICLECATEGORY"  type="char" />                      <param name="VEHICLEPRICE" type="char" />                      <param name="FRAUDFOUND" type="int" />                      <param name="POLICYNUMBER" type="int" />                      <param name="REPNUMBER" type="int" />                      <param name="DEDUCTIBLE"   type="int" />                      <param name="DRIVERRATING"  type="int" />                      <param name="DAYSPOLICYACCIDENT"   type="char" />                      <param name="DAYSPOLICYCLAIM" type="char" />                      <param name="PASTNUMOFCLAIMS" type="char" />                      <param name="AGEOFVEHICLES" type="char" />                      <param name="AGEOFPOLICYHOLDER" type="char" />                      <param name="POLICEREPORTFILED" type="char" />                      <param name="WITNESSPRESNT" type="char" />                      <param name="AGENTTYPE" type="char" />                      <param name="NUMOFSUPP" type="char" />                      <param name="ADDRCHGCLAIM"   type="char" />                      <param name="NUMOFCARS" type="char" />                      <param name="CQLYEAR" type="int" />                      <param name="BASEPOLICY" type="char" />                                     <return-component-type>char</return-component-type>                                                      <sql><![CDATA[             SELECT to_char(PREDICTION_PROBABILITY(CLAIMSMODEL, '0' USING *))               AS probability             FROM (SELECT  :CQLMONTH AS MONTH,                                            :WEEKOFMONTH AS WEEKOFMONTH,                          :DAYOFWEEK AS DAYOFWEEK,                           :MAKE AS MAKE,                           :ACCIDENTAREA AS ACCIDENTAREA,                           :DAYOFWEEKCLAIMED AS DAYOFWEEKCLAIMED,                           :MONTHCLAIMED AS MONTHCLAIMED,                           :WEEKOFMONTHCLAIMED,                             :SEX AS SEX,                           :MARITALSTATUS AS MARITALSTATUS,                            :AGE AS AGE,                           :FAULT AS FAULT,                           :POLICYTYPE AS POLICYTYPE,                            :VEHICLECATEGORY AS VEHICLECATEGORY,                           :VEHICLEPRICE AS VEHICLEPRICE,                           :FRAUDFOUND AS FRAUDFOUND,                           :POLICYNUMBER AS POLICYNUMBER,                           :REPNUMBER AS REPNUMBER,                           :DEDUCTIBLE AS DEDUCTIBLE,                            :DRIVERRATING AS DRIVERRATING,                           :DAYSPOLICYACCIDENT AS DAYSPOLICYACCIDENT,                            :DAYSPOLICYCLAIM AS DAYSPOLICYCLAIM,                           :PASTNUMOFCLAIMS AS PASTNUMOFCLAIMS,                           :AGEOFVEHICLES AS AGEOFVEHICLES,                           :AGEOFPOLICYHOLDER AS AGEOFPOLICYHOLDER,                           :POLICEREPORTFILED AS POLICEREPORTFILED,                           :WITNESSPRESNT AS WITNESSPRESENT,                           :AGENTTYPE AS AGENTTYPE,                           :NUMOFSUPP AS NUMOFSUPP,                           :ADDRCHGCLAIM AS ADDRCHGCLAIM,                            :NUMOFCARS AS NUMOFCARS,                           :CQLYEAR AS YEAR,                           :BASEPOLICY AS BASEPOLICY                 FROM dual)                 ]]>         </sql>        </function>     </jc:jdbc-ctx> </jdbcctxconfig:config> 2.      Invoking the function for each event. Once this function is defined, you can invoke it from CQL as follows: <?xml version="1.0" encoding="UTF-8"?> <wlevs:config xmlns:wlevs="http://www.bea.com/ns/wlevs/config/application">   <processor>     <name>DataMiningProc</name>     <rules>        <query id="q1"><![CDATA[                     ISTREAM(SELECT S.CQLMONTH,                                   S.WEEKOFMONTH,                                   S.DAYOFWEEK, S.MAKE,                                   :                                         S.BASEPOLICY,                                    C.F AS probability                                                 FROM                                 StreamDataChannel [NOW] AS S,                                 TABLE(prediction2@Oracle11gR2(S.CQLMONTH,                                      S.WEEKOFMONTH,                                      S.DAYOFWEEK,                                       S.MAKE, ...,                                      S.BASEPOLICY) AS F of char) AS C)                       ]]></query>                 </rules>               </processor>           </wlevs:config>   Finally, the last stage in the EPN prints out the probability of the event being an anomaly. One can also define a threshold in CQL to filter out events that are normal, i.e., below a certain mark as defined by the analyst or designer. Sample Runs: Now let's see how this behaves when events are streamed through CEP. We use only two events for brevity, one normal and other one not. This is one of the "normal" looking events and the probability of it being anomalous is less than 60%. Event is: eventType=DataMiningOutEvent object=q1  time=2904821976256 S.CQLMONTH=Dec, S.WEEKOFMONTH=5, S.DAYOFWEEK=Wednesday, S.MAKE=Honda, S.ACCIDENTAREA=Urban, S.DAYOFWEEKCLAIMED=Tuesday, S.MONTHCLAIMED=Jan, S.WEEKOFMONTHCLAIMED=1, S.SEX=Female, S.MARITALSTATUS=Single, S.AGE=21, S.FAULT=Policy Holder, S.POLICYTYPE=Sport - Liability, S.VEHICLECATEGORY=Sport, S.VEHICLEPRICE=more than 69000, S.FRAUDFOUND=0, S.POLICYNUMBER=1, S.REPNUMBER=12, S.DEDUCTIBLE=300, S.DRIVERRATING=1, S.DAYSPOLICYACCIDENT=more than 30, S.DAYSPOLICYCLAIM=more than 30, S.PASTNUMOFCLAIMS=none, S.AGEOFVEHICLES=3 years, S.AGEOFPOLICYHOLDER=26 to 30, S.POLICEREPORTFILED=No, S.WITNESSPRESENT=No, S.AGENTTYPE=External, S.NUMOFSUPP=none, S.ADDRCHGCLAIM=1 year, S.NUMOFCARS=3 to 4, S.CQLYEAR=1994, S.BASEPOLICY=Liability, probability=.58931702982118561 isTotalOrderGuarantee=true\nAnamoly probability: .58931702982118561 However, the following event is scored as an anomaly with a very high probability of  89%. So there is likely to be something wrong with it. A close look reveals that the value of "deductible" field (10000) is not "normal". What exactly constitutes normal here?. If you run the query on the database to find ALL distinct values for the "deductible" field, it returns the following set: {300, 400, 500, 700} Event is: eventType=DataMiningOutEvent object=q1  time=2598483773496 S.CQLMONTH=Dec, S.WEEKOFMONTH=5, S.DAYOFWEEK=Wednesday, S.MAKE=Honda, S.ACCIDENTAREA=Urban, S.DAYOFWEEKCLAIMED=Tuesday, S.MONTHCLAIMED=Jan, S.WEEKOFMONTHCLAIMED=1, S.SEX=Female, S.MARITALSTATUS=Single, S.AGE=21, S.FAULT=Policy Holder, S.POLICYTYPE=Sport - Liability, S.VEHICLECATEGORY=Sport, S.VEHICLEPRICE=more than 69000, S.FRAUDFOUND=0, S.POLICYNUMBER=1, S.REPNUMBER=12, S.DEDUCTIBLE=10000, S.DRIVERRATING=1, S.DAYSPOLICYACCIDENT=more than 30, S.DAYSPOLICYCLAIM=more than 30, S.PASTNUMOFCLAIMS=none, S.AGEOFVEHICLES=3 years, S.AGEOFPOLICYHOLDER=26 to 30, S.POLICEREPORTFILED=No, S.WITNESSPRESENT=No, S.AGENTTYPE=External, S.NUMOFSUPP=none, S.ADDRCHGCLAIM=1 year, S.NUMOFCARS=3 to 4, S.CQLYEAR=1994, S.BASEPOLICY=Liability, probability=.89171554529576691 isTotalOrderGuarantee=true\nAnamoly probability: .89171554529576691 Conclusion: By way of this example, we show: real-time scoring of events as they flow through CEP leveraging Oracle Data Mining.how CEP applications can invoke complex arbitrary external computations (function shipping) in an RDBMS.

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• Read array dump output and generates the correspondent XML file

  - by Christian

  Hi, The text below is the dump of a multidimensional array, dumped by the var_dump() PHP function. I need a Java function that reads a file with a content like this (attached) and returns it in XML. For a reference, in site http://pear.php.net/package/Var_Dump/ you can find the code (in PHP) that generates dumps in XML, so all neeeded logic is there (I think). I will be waiting for your feedback. Regards, Christian array(1) { ["Processo"]= array(60) { ["Sistema"]= string(6) "E-PROC" ["UF"]= string(2) "RS" ["DataConsulta"]= string(19) "11/05/2010 17:59:17" ["Processo"]= string(20) "50000135320104047100" ["NumRegistJudici"]= string(20) "50000135320104047100" ["IdProcesso"]= string(30) "711262958983115560390000000001" ["SeqProcesso"]= string(1) "1" ["Autuado"]= string(19) "08/01/2010 12:04:47" ["StatusProcesso"]= string(1) "M" ["ComSituacaoProcesso"]= string(2) "00" ["Situacao"]= string(9) "MOVIMENTO" ["IdClasseJudicial"]= string(10) "0000000112" ["DesClasse"]= string(18) "INQUÉRITO POLICIAL" ["CodClasse"]= string(6) "000120" ["SigClasse"]= string(3) "INQ" ["DesTipoInquerito"]= string(0) "" ["CodCompetencia"]= string(2) "21" ["IdLocalidadeJudicial"]= string(4) "7150" ["ClasseSigAutor"]= string(5) "AUTOR" ["ClasseDesAutor"]= string(5) "AUTOR" ["ClasseSigReu"]= string(7) "INDICDO" ["ClasseDesReu"]= string(9) "INDICIADO" ["ClasseCodReu"]= string(2) "64" ["TipoAcao"]= string(8) "Criminal" ["TipoProcessoJudicial"]= string(1) "2" ["CodAssuntoPrincipal"]= string(6) "051801" ["CodLocalidadeJudicial"]= string(2) "00" ["IdAssuntoPrincipal"]= string(4) "1504" ["IdLocalizadorOrgaoPrincipal"]= string(30) "711264420823128430420000000001" ["ChaveConsulta"]= string(12) "513009403710" ["NumAdministrativo"]= NULL ["Magistrado"]= string(28) "RICARDO HUMBERTO SILVA BORNE" ["IdOrgaoJuizo"]= string(9) "710000085" ["IdOrgaoJuizoOriginario"]= string(9) "710000085" ["DesOrgaoJuizo"]= string(45) "JUÍZO FED. DA 02A VF CRIMINAL DE PORTO ALEGRE" ["SigOrgaoJuizo"]= string(10) "RSPOACR02F" ["CodOrgaoJuizo"]= string(9) "RS0000085" ["IdOrgaoSecretaria"]= string(9) "710000084" ["DesOrgaoSecretaria"]= string(31) "02a VF CRIMINAL DE PORTO ALEGRE" ["SigOrgaoSecretaria"]= string(9) "RSPOACR02" ["CodOrgaoSecretaria"]= string(9) "RS0000084" ["IdSigilo"]= string(1) "0" ["IdUsuario"]= string(30) "711262951173995330420000000001" ["DesSigilo"]= string(10) "Sem Sigilo" ["Localizador"]= string(25) "EM TRÂMITE ENTRE PF E MPF" ["TotalCda"]= int(0) ["DesIpl"]= string(8) "012/2010" ["Assunto"]= array(1) { [0]= array(4) { ["IdAssuntoJudicial"]= string(4) "1504" ["SeqAssunto"]= string(1) "1" ["CodAssunto"]= string(6) "051801" ["DesAssunto"]= string(84) "Moeda Falsa / Assimilados (arts. 289 e parágrafos e 290), Crimes contra a Fé Pública" } } ["ParteAutor"]= array(1) { [0]= array(12) { ["IdPessoa"]= string(30) "771230778800100040000000000508" ["TipoPessoa"]= string(3) "ENT" ["Nome"]= string(15) "POLÍCIA FEDERAL" ["Identificacao"]= string(14) "79621439000191" ["SinPartePrincipal"]= string(1) "S" ["IdProcessoParte"]= string(30) "711262958983115560390000000002" ["IdProcessoParteAtributo"]= NULL ["IdRepresentacao"]= NULL ["TipoRepresentacao"]= NULL ["AtributosProcessoParte"]= NULL ["Relacao"]= NULL ["Procurador"]= array(6) { [0]= array(4) { ["Nome"]= string(25) "SOLON RAMOS CARDOSO FILHO" ["Sigla"]= string(13) "cor-sr-dpf-rs" ["IdUsuarioProcurador"]= string(30) "711262893271855450420000000001" ["TipoUsuario"]= string(3) "CPF" } [1]= array(4) { ["Nome"]= string(18) "LUCIANA IOP CECHIN" ["Sigla"]= string(11) "luciana.lic" ["IdUsuarioProcurador"]= string(30) "711262946806708880420000000001" ["TipoUsuario"]= string(3) "CPF" } [2]= array(4) { ["Nome"]= string(31) "ALEXANDRE DA SILVEIRA ISBARROLA" ["Sigla"]= string(15) "drcor-sr-dpf-rs" ["IdUsuarioProcurador"]= string(30) "711262949451860560420000000001" ["TipoUsuario"]= string(3) "CPF" } [3]= array(4) { ["Nome"]= string(24) "JUCÉLIA TERESINHA PISONI" ["Sigla"]= string(11) "jucelia.jtp" ["IdUsuarioProcurador"]= string(30) "711262950492275450420000000001" ["TipoUsuario"]= string(3) "CPF" } [4]= array(4) { ["Nome"]= string(32) "MARCOS ANTONIO SIQUEIRA PICININI" ["Sigla"]= string(13) "picinini.masp" ["IdUsuarioProcurador"]= string(30) "711262951173995330420000000001" ["TipoUsuario"]= string(3) "APF" } [5]= array(4) { ["Nome"]= string(20) "PRISCILLA BURLACENKO" ["Sigla"]= string(12) "priscilla.pb" ["IdUsuarioProcurador"]= string(30) "711262955631630740420000000001" ["TipoUsuario"]= string(3) "DPF" } } } } ["ParteReu"]= array(1) { [0]= array(11) { ["IdPessoa"]= string(30) "711262958983115560390000000001" ["TipoPessoa"]= string(2) "PF" ["Nome"]= string(8) "A APURAR" ["Identificacao"]= NULL ["SinPartePrincipal"]= string(1) "S" ["IdProcessoParte"]= string(30) "711262958983115560390000000001" ["IdProcessoParteAtributo"]= NULL ["IdRepresentacao"]= NULL ["TipoRepresentacao"]= NULL ["AtributosProcessoParte"]= NULL ["Relacao"]= NULL } } ["OutraParte"]= array(1) { [0]= array(10) { ["Nome"]= string(26) "MINISTÉRIO PÚBLICO FEDERAL" ["CodTipoParte"]= string(3) "114" ["DesTipoParte"]= string(3) "MPF" ["SinPolo"]= string(1) "N" ["Identificacao"]= string(13) "3636198000192" ["SinPartePrincipal"]= string(1) "N" ["IdProcessoParte"]= string(30) "711262958983115560390000000003" ["IdPessoa"]= string(30) "771230778800100040000000000217" ["TipoPessoa"]= string(3) "ENT" ["Procurador"]= array(1) { [0]= array(4) { ["Nome"]= string(25) "MARIA VALESCA DE MESQUITA" ["IdUsuarioProcurador"]= string(30) "711265220162198740420000000001" ["TipoUsuario"]= string(1) "P" ["Sigla"]= string(5) "pr528" } } } } ["DadoComplementar"]= array(6) { [0]= array(5) { ["DesDadoComplem"]= string(21) "Antecipação de Tutela" ["ValorDadoComplem"]= string(13) "Não Requerida" ["IdDadoComplementar"]= string(1) "1" ["NumIdProcessoDadoComplem"]= string(30) "711262958983115560390000000003" ["IdDadoComplementarValor"]= string(1) "4" } [1]= array(5) { ["DesDadoComplem"]= string(16) "Justiça Gratuita" ["ValorDadoComplem"]= string(13) "Não Requerida" ["IdDadoComplementar"]= string(1) "4" ["NumIdProcessoDadoComplem"]= string(30) "711262958983115560390000000001" ["IdDadoComplementarValor"]= string(1) "3" } [2]= array(5) { ["DesDadoComplem"]= string(15) "Petição Urgente" ["ValorDadoComplem"]= string(3) "Não" ["IdDadoComplementar"]= string(1) "5" ["NumIdProcessoDadoComplem"]= string(30) "711262958983115560390000000004" ["IdDadoComplementarValor"]= string(1) "2" } [3]= array(5) { ["DesDadoComplem"]= string(22) "Prioridade Atendimento" ["ValorDadoComplem"]= string(3) "Não" ["IdDadoComplementar"]= string(1) "2" ["NumIdProcessoDadoComplem"]= string(30) "711262958983115560390000000006" ["IdDadoComplementarValor"]= string(1) "2" } [4]= array(5) { ["DesDadoComplem"]= string(9) "Réu Preso" ["ValorDadoComplem"]= string(3) "Não" ["IdDadoComplementar"]= string(1) "6" ["NumIdProcessoDadoComplem"]= string(30) "711262958983115560390000000002" ["IdDadoComplementarValor"]= string(1) "2" } [5]= array(5) { ["DesDadoComplem"]= string(24) "Vista Ministério Público" ["ValorDadoComplem"]= string(3) "Sim" ["IdDadoComplementar"]= string(1) "3" ["NumIdProcessoDadoComplem"]= string(30) "711262958983115560390000000005" ["IdDadoComplementarValor"]= string(1) "1" } } ["SemPrazoAbrir"]= bool(true) ["Evento"]= array(8) { [0]= array(18) { ["IdProcessoEvento"]= string(30) "711269271039215440420000000001" ["IdEvento"]= string(3) "228" ["IdTipoPeticaoJudicial"]= string(3) "166" ["SeqEvento"]= string(1) "8" ["DataHora"]= string(19) "22/03/2010 12:19:16" ["SinExibeDesEvento"]= string(1) "S" ["SinUsuarioInterno"]= string(1) "N" ["IdGrupoEvento"]= string(1) "4" ["SinVisualizaDocumentoExterno"]= string(1) "N" ["Complemento"]= string(7) "90 DIAS" ["DesEventoSemComplemento"]= string(27) "PETIÇÃO PROTOCOLADA JUNTADA" ["CodEvento"]= string(10) "0000000852" ["DesEvento"]= string(37) "PETIÇÃO PROTOCOLADA JUNTADA - 90 DIAS" ["DesAlternativaEvento"]= NULL ["Usuario"]= string(7) "ap18785" ["idUsuario"]= string(30) "711263330517182580420000000001" ["DesPeticao"]= string(25) "DILAÇÃO DE PRAZO DEFERIDA" ["DescricaoCompleta"]= string(75) "PETIÇÃO PROTOCOLADA JUNTADA - 90 DIAS - DILAÇÃO DE PRAZO DEFERIDA - 90 DIAS" } [1]= array(18) { ["IdProcessoEvento"]= string(30) "711269032501923580420000000001" ["IdEvento"]= string(3) "228" ["IdTipoPeticaoJudicial"]= string(3) "166" ["SeqEvento"]= string(1) "7" ["DataHora"]= string(19) "19/03/2010 18:04:59" ["SinExibeDesEvento"]= string(1) "S" ["SinUsuarioInterno"]= string(1) "N" ["IdGrupoEvento"]= string(1) "4" ["SinVisualizaDocumentoExterno"]= string(1) "N" ["Complemento"]= string(7) "90 DIAS" ["DesEventoSemComplemento"]= string(27) "PETIÇÃO PROTOCOLADA JUNTADA" ["CodEvento"]= string(10) "0000000852" ["DesEvento"]= string(37) "PETIÇÃO PROTOCOLADA JUNTADA - 90 DIAS" ["DesAlternativaEvento"]= NULL ["Usuario"]= string(5) "pr700" ["idUsuario"]= string(30) "711262976146980920420000000002" ["DesPeticao"]= string(25) "DILAÇÃO DE PRAZO DEFERIDA" ["DescricaoCompleta"]= string(75) "PETIÇÃO PROTOCOLADA JUNTADA - 90 DIAS - DILAÇÃO DE PRAZO DEFERIDA - 90 DIAS" } [2]= array(19) { ["IdProcessoEvento"]= string(30) "711268077089625240420000000001" ["IdEvento"]= string(3) "228" ["IdTipoPeticaoJudicial"]= string(3) "165" ["SeqEvento"]= string(1) "6" ["DataHora"]= string(19) "08/03/2010 16:55:48" ["SinExibeDesEvento"]= string(1) "N" ["SinUsuarioInterno"]= string(1) "N" ["IdGrupoEvento"]= string(1) "4" ["SinVisualizaDocumentoExterno"]= string(1) "N" ["Complemento"]= NULL ["DesEventoSemComplemento"]= string(27) "PETIÇÃO PROTOCOLADA JUNTADA" ["CodEvento"]= string(10) "0000000852" ["DesEvento"]= string(27) "PETIÇÃO PROTOCOLADA JUNTADA" ["DesAlternativaEvento"]= NULL ["Usuario"]= string(13) "picinini.masp" ["idUsuario"]= string(30) "711262951173995330420000000001" ["Documento"]= array(2) { [0]= array(6) { ["IdUsuario"]= string(30) "711262951173995330420000000001" ["IdDocumento"]= string(30) "711268077089625240420000000001" ["SeqDocumento"]= string(1) "1" ["SigTipoDocumento"]= string(4) "CERT" ["IdSigilo"]= string(1) "0" ["DesSigilo"]= string(10) "Sem Sigilo" } [1]= array(6) { ["IdUsuario"]= string(30) "711262951173995330420000000001" ["IdDocumento"]= string(30) "711268077089625240420000000002" ["SeqDocumento"]= string(1) "2" ["SigTipoDocumento"]= string(4) "DESP" ["IdSigilo"]= string(1) "0" ["DesSigilo"]= string(10) "Sem Sigilo" } } ["DesPeticao"]= string(26) "PEDIDO DE DILAÇÃO DE PRAZO" ["DescricaoCompleta"]= string(26) "PEDIDO DE DILAÇÃO DE PRAZO" } [3]= array(19) { ["IdProcessoEvento"]= string(30) "711267732906972600420000000001" ["IdEvento"]= string(3) "228" ["IdTipoPeticaoJudicial"]= string(2) "52" ["SeqEvento"]= string(1) "5" ["DataHora"]= string(19) "04/03/2010 17:20:29" ["SinExibeDesEvento"]= string(1) "N" ["SinUsuarioInterno"]= string(1) "N" ["IdGrupoEvento"]= string(1) "4" ["SinVisualizaDocumentoExterno"]= string(1) "N" ["Complemento"]= NULL ["DesEventoSemComplemento"]= string(27) "PETIÇÃO PROTOCOLADA JUNTADA" ["CodEvento"]= string(10) "0000000852" ["DesEvento"]= string(27) "PETIÇÃO PROTOCOLADA JUNTADA" ["DesAlternativaEvento"]= NULL ["Usuario"]= string(5) "pr700" ["idUsuario"]= string(30) "711262976146980920420000000002" ["Documento"]= array(1) { [0]= array(6) { ["IdUsuario"]= string(30) "711262976146980920420000000002" ["IdDocumento"]= string(30) "711267732906972600420000000001" ["SeqDocumento"]= string(1) "1" ["SigTipoDocumento"]= string(3) "PET" ["IdSigilo"]= string(1) "0" ["DesSigilo"]= string(10) "Sem Sigilo" } } ["DesPeticao"]= string(7) "PETIÇÃO" ["DescricaoCompleta"]= string(7) "PETIÇÃO" } [4]= array(19) { ["IdProcessoEvento"]= string(30) "711265889365256290420000000001" ["IdEvento"]= string(3) "228" ["IdTipoPeticaoJudicial"]= string(3) "165" ["SeqEvento"]= string(1) "4" ["DataHora"]= string(19) "11/02/2010 09:59:04" ["SinExibeDesEvento"]= string(1) "N" ["SinUsuarioInterno"]= string(1) "N" ["IdGrupoEvento"]= string(1) "4" ["SinVisualizaDocumentoExterno"]= string(1) "N" ["Complemento"]= NULL ["DesEventoSemComplemento"]= string(27) "PETIÇÃO PROTOCOLADA JUNTADA" ["CodEvento"]= string(10) "0000000852" ["DesEvento"]= string(27) "PETIÇÃO PROTOCOLADA JUNTADA" ["DesAlternativaEvento"]= NULL ["Usuario"]= string(13) "picinini.masp" ["idUsuario"]= string(30) "711262951173995330420000000001" ["Documento"]= array(2) { [0]= array(6) { ["IdUsuario"]= string(30) "711262951173995330420000000001" ["IdDocumento"]= string(30) "711265222866995860420000000001" ["SeqDocumento"]= string(1) "1" ["SigTipoDocumento"]= string(4) "PORT" ["IdSigilo"]= string(1) "0" ["DesSigilo"]= string(10) "Sem Sigilo" } [1]= array(6) { ["IdUsuario"]= string(30) "711262951173995330420000000001" ["IdDocumento"]= string(30) "711265222866995860420000000002" ["SeqDocumento"]= string(1) "2" ["SigTipoDocumento"]= string(3) "OUT" ["IdSigilo"]= string(1) "0" ["DesSigilo"]= string(10) "Sem Sigilo" } } ["DesPeticao"]= string(26) "PEDIDO DE DILAÇÃO DE PRAZO" ["DescricaoCompleta"]= string(26) "PEDIDO DE DILAÇÃO DE PRAZO" } [5]= array(19) { ["IdProcessoEvento"]= string(30) "711263991150788270420000000001" ["IdEvento"]= string(3) "228" ["IdTipoPeticaoJudicial"]= string(2) "52" ["SeqEvento"]= string(1) "3" ["DataHora"]= string(19) "20/01/2010 10:50:05" ["SinExibeDesEvento"]= string(1) "N" ["SinUsuarioInterno"]= string(1) "N" ["IdGrupoEvento"]= string(1) "4" ["SinVisualizaDocumentoExterno"]= string(1) "N" ["Complemento"]= NULL ["DesEventoSemComplemento"]= string(27) "PETIÇÃO PROTOCOLADA JUNTADA" ["CodEvento"]= string(10) "0000000852" ["DesEvento"]= string(27) "PETIÇÃO PROTOCOLADA JUNTADA" ["DesAlternativaEvento"]= NULL ["Usuario"]= string(13) "picinini.masp" ["idUsuario"]= string(30) "711262951173995330420000000001" ["Documento"]= array(4) { [0]= array(6) { ["IdUsuario"]= string(30) "711262951173995330420000000001" ["IdDocumento"]= string(30) "711263991150788270420000000001" ["SeqDocumento"]= string(1) "1" ["SigTipoDocumento"]= string(4) "DECL" ["IdSigilo"]= string(1) "0" ["DesSigilo"]= string(10) "Sem Sigilo" } [1]= array(6) { ["IdUsuario"]= string(30) "711262951173995330420000000001" ["IdDocumento"]= string(30) "711263991150788270420000000002" ["SeqDocumento"]= string(1) "2" ["SigTipoDocumento"]= string(4) "DECL" ["IdSigilo"]= string(1) "0" ["DesSigilo"]= string(10) "Sem Sigilo" } [2]= array(6) { ["IdUsuario"]= string(30) "711262951173995330420000000001" ["IdDocumento"]= string(30) "711263991150788270420000000003" ["SeqDocumento"]= string(1) "3" ["SigTipoDocumento"]= string(4) "DECL" ["IdSigilo"]= string(1) "0" ["DesSigilo"]= string(10) "Sem Sigilo" } [3]= array(6) { ["IdUsuario"]= string(30) "711262951173995330420000000001" ["IdDocumento"]= string(30) "711263991150788270420000000004" ["SeqDocumento"]= string(1) "4" ["SigTipoDocumento"]= string(4) "DECL" ["IdSigilo"]= string(1) "0" ["DesSigilo"]= string(10) "Sem Sigilo" } } ["DesPeticao"]= string(7) "PETIÇÃO" ["DescricaoCompleta"]= string(7) "PETIÇÃO" } [6]= array(19) { ["IdProcessoEvento"]= string(30) "711263955058688620420000000001" ["IdEvento"]= string(3) "228" ["IdTipoPeticaoJudicial"]= string(2) "52" ["SeqEvento"]= string(1) "2" ["DataHora"]= string(19) "20/01/2010 00:40:39" ["SinExibeDesEvento"]= string(1) "N" ["SinUsuarioInterno"]= string(1) "N" ["IdGrupoEvento"]= string(1) "4" ["SinVisualizaDocumentoExterno"]= string(1) "N" ["Complemento"]= NULL ["DesEventoSemComplemento"]= string(27) "PETIÇÃO PROTOCOLADA JUNTADA" ["CodEvento"]= string(10) "0000000852" ["DesEvento"]= string(27) "PETIÇÃO PROTOCOLADA JUNTADA" ["DesAlternativaEvento"]= NULL ["Usuario"]= string(13) "picinini.masp" ["idUsuario"]= string(30) "711262951173995330420000000001" ["Documento"]= array(6) { [0]= array(6) { ["IdUsuario"]= string(30) "711262951173995330420000000001" ["IdDocumento"]= string(30) "711263229632249660420000000001" ["SeqDocumento"]= string(1) "1" ["SigTipoDocumento"]= string(3) "OUT" ["IdSigilo"]= string(1) "0" ["DesSigilo"]= string(10) "Sem Sigilo" } [1]= array(6) { ["IdUsuario"]= string(30) "711262951173995330420000000001" ["IdDocumento"]= string(30) "711263229632249660420000000002" ["SeqDocumento"]= string(1) "2" ["SigTipoDocumento"]= string(3) "OUT" ["IdSigilo"]= string(1) "0" ["DesSigilo"]= string(10) "Sem Sigilo" } [2]= array(6) { ["IdUsuario"]= string(30) "711262951173995330420000000001" ["IdDocumento"]= string(30) "711263229632249660420000000003" ["SeqDocumento"]= string(1) "3" ["SigTipoDocumento"]= string(3) "OUT" ["IdSigilo"]= string(1) "0" ["DesSigilo"]= string(10) "Sem Sigilo" } [3]= array(6) { ["IdUsuario"]= string(30) "711262951173995330420000000001" ["IdDocumento"]= string(30) "711263229632249660420000000004" ["SeqDocumento"]= string(1) "4" ["SigTipoDocumento"]= string(3) "OUT" ["IdSigilo"]= string(1) "0" ["DesSigilo"]= string(10) "Sem Sigilo" } [4]= array(6) { ["IdUsuario"]= string(30) "711262951173995330420000000001" ["IdDocumento"]= string(30) "711263229632249660420000000005" ["SeqDocumento"]= string(1) "5" ["SigTipoDocumento"]= string(3) "OUT" ["IdSigilo"]= string(1) "0" ["DesSigilo"]= string(10) "Sem Sigilo" } [5]= array(6) { ["IdUsuario"]= string(30) "711262951173995330420000000001" ["IdDocumento"]= string(30) "711263229632249660420000000006" ["SeqDocumento"]= string(1) "6" ["SigTipoDocumento"]= string(3) "OUT" ["IdSigilo"]= string(1) "0" ["DesSigilo"]= string(10) "Sem Sigilo" } } ["DesPeticao"]= string(7) "PETIÇÃO" ["DescricaoCompleta"]= string(7) "PETIÇÃO" } [7]= array(19) { ["IdProcessoEvento"]= string(30) "711262958983115560390000000001" ["IdEvento"]= string(3) "430" ["IdTipoPeticaoJudicial"]= NULL ["SeqEvento"]= string(1) "1" ["DataHora"]= string(19) "08/01/2010 12:04:47" ["SinExibeDesEvento"]= NULL ["SinUsuarioInterno"]= string(1) "N" ["IdGrupoEvento"]= string(1) "0" ["SinVisualizaDocumentoExterno"]= string(1) "N" ["Complemento"]= NULL ["DesEventoSemComplemento"]= string(56) "Distribuição/Atribuição Ordinária por sorteio eletrônico" ["CodEvento"]= string(6) "030101" ["DesEvento"]= string(56) "Distribuição/Atribuição Ordinária por sorteio eletrônico" ["DesAlternativaEvento"]= NULL ["Usuario"]= string(13) "picinini.masp" ["idUsuario"]= string(30) "711262951173995330420000000001" ["Documento"]= array(4) { [0]= array(6) { ["IdUsuario"]= string(30) "711262951173995330420000000001" ["IdDocumento"]= string(30) "711262956008922510390000000001" ["SeqDocumento"]= string(1) "1" ["SigTipoDocumento"]= string(4) "PORT" ["IdSigilo"]= string(1) "0" ["DesSigilo"]= string(10) "Sem Sigilo" } [1]= array(6) { ["IdUsuario"]= string(30) "711262951173995330420000000001" ["IdDocumento"]= string(30) "711262956008922510390000000002" ["SeqDocumento"]= string(1) "2" ["SigTipoDocumento"]= string(4) "OFIC" ["IdSigilo"]= string(1) "0" ["DesSigilo"]= string(10) "Sem Sigilo" } [2]= array(6) { ["IdUsuario"]= string(30) "711262951173995330420000000001" ["IdDocumento"]= string(30) "711262956008922510390000000003" ["SeqDocumento"]= string(1) "3" ["SigTipoDocumento"]= string(3) "OUT" ["IdSigilo"]= string(1) "0" ["DesSigilo"]= string(10) "Sem Sigilo" } [3]= array(6) { ["IdUsuario"]= string(30) "711262951173995330420000000001" ["IdDocumento"]= string(30) "711262956008922510390000000004" ["SeqDocumento"]= string(1) "4" ["SigTipoDocumento"]= string(3) "OUT" ["IdSigilo"]= string(1) "0" ["DesSigilo"]= string(10) "Sem Sigilo" } } ["DesPeticao"]= string(56) "Distribuição/Atribuição Ordinária por sorteio eletrônico" ["DescricaoCompleta"]= string(56) "Distribuição/Atribuição Ordinária por sorteio eletrônico" } } ["ValCausa"]= string(4) "0.00" ["OrgaoJul"]= string(45) "JUÍZO FED. DA 02A VF CRIMINAL DE PORTO ALEGRE" ["CodOrgaoJul"]= string(9) "RS0000085" ["OrgaoColegiado"]= NULL ["CodOrgaoColegiado"]= NULL ["CodOrgaoColegiadoSecretaria"]= NULL } }

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• Problem with my whiteboard application

  - by swift

  I have to develop a whiteboard application in which both the local user and the remote user should be able to draw simultaneously, is this possible? If possible then any logic? I have already developed a code but in which i am not able to do this, when the remote user starts drawing the shape which i am drawing is being replaced by his shape and co-ordinates. This problem is only when both draw simultaneously. any idea guys? Here is my code class Paper extends JPanel implements MouseListener,MouseMotionListener,ActionListener { static BufferedImage image; int bpressed; Color color; Point start; Point end; Point mp; Button elipse=new Button("elipse"); Button rectangle=new Button("rect"); Button line=new Button("line"); Button empty=new Button(""); JButton save=new JButton("Save"); JButton erase=new JButton("Erase"); String selected; int ex,ey;//eraser DatagramSocket dataSocket; JButton button = new JButton("test"); Client client; Point p=new Point(); int w,h; public Paper(DatagramSocket dataSocket) { this.dataSocket=dataSocket; client=new Client(dataSocket); System.out.println("paper"); setBackground(Color.white); addMouseListener(this); addMouseMotionListener(this); color = Color.black; setBorder(BorderFactory.createLineBorder(Color.black)); //save.setPreferredSize(new Dimension(100,20)); save.setMaximumSize(new Dimension(75,27)); erase.setMaximumSize(new Dimension(75,27)); } public void paintComponent(Graphics g) { try { g.drawImage(image, 0, 0, this); Graphics2D g2 = (Graphics2D)g; g2.setPaint(Color.black); if(selected==("elipse")) g2.drawOval(start.x, start.y,(end.x-start.x),(end.y-start.y)); else if(selected==("rect")) g2.drawRect(start.x, start.y, (end.x-start.x),(end.y-start.y)); else if(selected==("line")) g2.drawLine(start.x,start.y,end.x,end.y); } catch(Exception e) {} } //Function to draw the shape on image public void draw() { Graphics2D g2 = image.createGraphics(); g2.setPaint(color); if(selected=="line") g2.drawLine(start.x, start.y, end.x, end.y); if(selected=="elipse") g2.drawOval(start.x, start.y, (end.x-start.x),(end.y-start.y)); if(selected=="rect") g2.drawRect(start.x, start.y, (end.x-start.x),(end.y-start.y)); repaint(); g2.dispose(); start=null; } //To add the point to the board which is broadcasted by the server public synchronized void addPoint(Point ps,String varname,String shape,String event) { try { if(end==null) end = new Point(); if(start==null) start = new Point(); if(shape.equals("elipse")) selected="elipse"; else if(shape.equals("line")) selected="line"; else if(shape.equals("rect")) selected="rect"; else if(shape.equals("erase")) { selected="erase"; erase(); } if(end!=null && start!=null) { if(varname.equals("end")) end=ps; if(varname.equals("mp")) mp=ps; if(varname.equals("start")) start=ps; if(event.equals("drag")) repaint(); else if(event.equals("release")) draw(); } } catch(Exception e) { e.printStackTrace(); } } //To set the size of the image public void setWidth(int x,int y) { System.out.println("("+x+","+y+")"); w=x; h=y; image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB); Graphics2D g2 = image.createGraphics(); g2.setPaint(Color.white); g2.fillRect(0,0,w,h); g2.dispose(); } //Function which provides the erase functionality public void erase() { Graphics2D pic=(Graphics2D) image.getGraphics(); pic.setPaint(Color.white); pic.fillRect(start.x, start.y, 10, 10); } //Function to add buttons into the panel, calling this function returns a panel public JPanel addButtons() { JPanel buttonpanel=new JPanel(); JPanel row1=new JPanel(); JPanel row2=new JPanel(); JPanel row3=new JPanel(); JPanel row4=new JPanel(); buttonpanel.setPreferredSize(new Dimension(80,80)); //buttonpanel.setMinimumSize(new Dimension(150,150)); row1.setLayout(new BoxLayout(row1,BoxLayout.X_AXIS)); row1.setPreferredSize(new Dimension(150,150)); row2.setLayout(new BoxLayout(row2,BoxLayout.X_AXIS)); row3.setLayout(new BoxLayout(row3,BoxLayout.X_AXIS)); row4.setLayout(new BoxLayout(row4,BoxLayout.X_AXIS)); buttonpanel.setLayout(new BoxLayout(buttonpanel,BoxLayout.Y_AXIS)); elipse.addActionListener(this); rectangle.addActionListener(this); line.addActionListener( this); save.addActionListener( this); erase.addActionListener( this); buttonpanel.add(Box.createRigidArea(new Dimension(10,10))); row1.add(elipse); row1.add(Box.createRigidArea(new Dimension(5,0))); row1.add(rectangle); buttonpanel.add(row1); buttonpanel.add(Box.createRigidArea(new Dimension(10,10))); row2.add(line); row2.add(Box.createRigidArea(new Dimension(5,0))); row2.add(empty); buttonpanel.add(row2); buttonpanel.add(Box.createRigidArea(new Dimension(10,10))); row3.add(save); buttonpanel.add(row3); buttonpanel.add(Box.createRigidArea(new Dimension(10,10))); row4.add(erase); buttonpanel.add(row4); return buttonpanel; } //To save the image drawn public void save() { try { ByteArrayOutputStream bos = new ByteArrayOutputStream(); JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(bos); JFileChooser fc = new JFileChooser(); fc.showSaveDialog(this); encoder.encode(image); byte[] jpgData = bos.toByteArray(); FileOutputStream fos = new FileOutputStream(fc.getSelectedFile()+".jpeg"); fos.write(jpgData); fos.close(); //add replce confirmation here } catch (IOException e) { System.out.println(e); } } public void mouseClicked(MouseEvent arg0) { // TODO Auto-generated method stub } @Override public void mouseEntered(MouseEvent arg0) { } public void mouseExited(MouseEvent arg0) { // TODO Auto-generated method stub } public void mousePressed(MouseEvent e) { if(selected=="line"||selected=="erase") { start=e.getPoint(); client.broadcast(start,"start", selected,"press"); } else if(selected=="elipse"||selected=="rect") { mp = e.getPoint(); client.broadcast(mp,"mp", selected,"press"); } } public void mouseReleased(MouseEvent e) { if(start!=null) { if(selected=="line") { end=e.getPoint(); client.broadcast(end,"end", selected,"release"); } else if(selected=="elipse"||selected=="rect") { end.x = Math.max(mp.x,e.getX()); end.y = Math.max(mp.y,e.getY()); client.broadcast(end,"end", selected,"release"); } draw(); } //start=null; } public void mouseDragged(MouseEvent e) { if(end==null) end = new Point(); if(start==null) start = new Point(); if(selected=="line") { end=e.getPoint(); client.broadcast(end,"end", selected,"drag"); } else if(selected=="erase") { start=e.getPoint(); erase(); client.broadcast(start,"start", selected,"drag"); } else if(selected=="elipse"||selected=="rect") { start.x = Math.min(mp.x,e.getX()); start.y = Math.min(mp.y,e.getY()); end.x = Math.max(mp.x,e.getX()); end.y = Math.max(mp.y,e.getY()); client.broadcast(start,"start", selected,"drag"); client.broadcast(end,"end", selected,"drag"); } repaint(); } @Override public void mouseMoved(MouseEvent arg0) { // TODO Auto-generated method stub } public void actionPerformed(ActionEvent e) { if(e.getSource()==elipse) selected="elipse"; if(e.getSource()==line) selected="line"; if(e.getSource()==rectangle) selected="rect"; if(e.getSource()==save) save(); if(e.getSource()==erase) { selected="erase"; erase(); } } } class Button extends JButton { String name; public Button(String name) { this.name=name; Dimension buttonSize = new Dimension(35,35); setMaximumSize(buttonSize); } public void paintComponent(Graphics g) { super.paintComponent(g); Graphics2D g2 = (Graphics2D)g; g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); //g2.setStroke(new BasicStroke(1.2f)); if (name == "line") g.drawLine(5,5,30,30); if (name == "elipse") g.drawOval(5,7,25,20); if (name== "rect") g.drawRect(5,5,25,23); } }

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• Obj-msg-send error in numberOfSectionsInTableView

  - by mukeshpawar

  import "AddBillerCategoryViewController.h" import "Globals.h" import "AddBillerViewController.h" import "AddBillerListViewController.h" import"KlinnkAppDelegate.h" @implementation AddBillerCategoryViewController @synthesize REASON, RESPVAR, currentAttribute,tbldata,strOptions; // This recipe adds a title for each section //Initialize the table view controller with the grouped style (AddBillerCategoryViewController *) init { if (self = [super initWithStyle:UITableViewStyleGrouped]);// self.title = @"Crayon Colors"; return self; } -(void)showBack { [[self navigationController] pushViewController:[[AddBillerViewController alloc] init] animated:YES]; } (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated { if ([viewController isKindOfClass:[AddBillerCategoryViewController class]]) { AddBillerCategoryViewController *controller = (AddBillerCategoryViewController *)viewController; [controller.tbldata reloadData]; } } (void)viewDidLoad { appDelegate = (KlinnkAppDelegate *)[[UIApplication sharedApplication] delegate]; appDelegate.catListArray.count; // Uncomment the following line to display an Edit button in the navigation bar for this view controller. // self.navigationItem.rightBarButtonItem = self.editButtonItem; //self.navigationItem.leftBarButtonItem = [[[UIBarButtonItem alloc] // initWithTitle:@"Back" // style:UIBarButtonItemStylePlain // target:self // action:@selector(showBack)] autorelease]; if(gotOK == 0) { //self.navigationItem.leftBarButtonItem.enabled = FALSE; dt = [[DateTime alloc] init]; strChannelID = @"IGLOO|MOBILE"; strDateTime = [dt findDateTime]; strTemp = [dt findSessionTime]; strSessionID = [appDelegate.KMobile stringByAppendingString:strTemp]; strResponseURL = @"http://115.113.110.139/Test/CbbpServerRequestHandler"; strResponseVar = @"serverResponseXML"; strRequestType = @"GETCATEGORY"; NSLog(@"Current Session id - %@", strSessionID); //conn = [[NSURLConnection alloc] init]; receivedData = [[NSMutableData data] retain]; //.................... currentAttribute = [[NSMutableString alloc] init]; // create XMl xmlData = [[NSData alloc] init]; xmlData = [self createXML]; // XMl has been created now convert it in to string xmlString = [[NSString alloc] initWithData:xmlData encoding:NSASCIIStringEncoding]; // Ataching other infromatin to he xml parameterString = [[NSString alloc] initWithString:@"mobileRequestXML="]; requestString = [[NSString alloc] init]; requestString = [parameterString stringByAppendingString:xmlString]; // give space betn two element. requestString = [requestString stringByReplacingOccurrencesOfString:@"<" withString:@" <"]; // Initalizing other parameters postData = [requestString dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES]; postLength = [NSString stringWithFormat:@"%d",[postData length]]; firstRequest = [[[NSMutableURLRequest alloc] init] autorelease]; REASON = [[NSMutableString alloc] init]; RESPVAR = [[NSMutableString alloc] init]; NSLog(@"\n \n Sending for 1st time........\n"); [self sendRequest]; NSLog(@"\n \n Sending for 2nd time........\n"); [self sendRequest]; NSLog(@"\n \n both request send........\n \n "); } //[tbldata reloadData]; [self retain]; [super viewDidLoad]; } -(void)sendRequest { finished = FALSE; NSLog(@"\n Sending Request \n\n %@", requestString); conn = [[NSURLConnection alloc] init]; if(gotOK == 0) [firstRequest setURL:[NSURL URLWithString:@"http://115.113.110.139/Test/CbbpMobileRequestHandler"]]; if(gotOK == 1) { [firstRequest setURL:[NSURL URLWithString:@"http://115.113.110.139//secure"]]; gotOK = 2; } [firstRequest setHTTPMethod:@"POST"]; [firstRequest setValue:postLength forHTTPHeaderField:@"Content-Length"]; [firstRequest setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"]; [firstRequest setHTTPBody:postData]; conn = [conn initWithRequest:firstRequest delegate:self startImmediately:YES]; [conn start]; while(!finished) { [[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]]; } if (conn) { //receivedData = [[NSMutableData data] retain]; NSLog(@"\n\n Received %d bytes of data",[receivedData length]); } else { NSLog(@"\n Not responding"); } } (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response { NSLog(@" \n Send didReciveResponse"); [receivedData setLength:0]; } (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data { NSLog(@" \n Send didReciveData"); [receivedData appendData:data]; } (void)connectionDidFinishLoading:(NSURLConnection *)connection { finished = TRUE; NSLog(@" \n Send didFinishLaunching"); // do something with the data // receivedData is declared as a method instance elsewhere NSLog(@"\n\n Succeeded! DIDFINISH Received %d bytes of data\n\n ",[receivedData length]); NSString *aStr = [[NSString alloc] initWithData:receivedData encoding:NSASCIIStringEncoding]; NSLog(aStr); //[conn release]; if([aStr isEqualToString:@"OK"]) gotOK = 1; NSLog(@" Value of gotOK - %d", gotOK); if(gotOK == 2) { responseData = [aStr dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES]; parser = [[NSXMLParser alloc] initWithData:responseData]; [parser setDelegate:self]; NSLog(@"\n start parsing"); [parser parse]; NSLog(@"\n PArsing over"); NSLog(@"\n check U / S and the RESVAR is - %@",RESPVAR); NSRange textRange; textRange =[aStr rangeOfString:@"<"]; if(textRange.location != NSNotFound) { if([RESPVAR isEqualToString:@"U"]) { self.navigationItem.rightBarButtonItem.enabled = TRUE; self.navigationItem.leftBarButtonItem.enabled = TRUE; NSLog(@" \n U......."); UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error" message:REASON delegate:self cancelButtonTitle:nil otherButtonTitles:@"OK", nil]; [alert show]; [alert release]; } if([RESPVAR isEqualToString:@"S"]) { NSLog(@"\n S........"); [[self navigationController] pushViewController:[[AddBillerCategoryViewController alloc] init] animated:YES]; //[self viewDidLoad]; //[tbldata reloadData]; } } else { UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Connection Problem" message:@"Enable to process your request at this time. Please try again." delegate:self cancelButtonTitle:nil otherButtonTitles:@"OK", nil]; [alert show]; [alert release]; //self.navigationItem.leftBarButtonItem.enabled = TRUE; } } NSLog(@"\n Last line of connectionDidFinish "); //[tableView reloadData]; } -(NSData *)createXML { NSString *strXmlNode = @" channel alliaceid session reqtype responseurl responsevar "; NSString *tempchannel = [strXmlNode stringByReplacingOccurrencesOfString:@"channel" withString:strChannelID options:NSBackwardsSearch range:NSMakeRange(0, [strXmlNode length])]; NSString *tempalliance = [tempchannel stringByReplacingOccurrencesOfString:@"alliaceid" withString:@"WALLET365" options:NSBackwardsSearch range:NSMakeRange(0, [tempchannel length])]; NSString *tempsession = [tempalliance stringByReplacingOccurrencesOfString:@"session" withString:strSessionID options:NSBackwardsSearch range:NSMakeRange(0, [tempalliance length])]; NSString *tempreqtype = [tempsession stringByReplacingOccurrencesOfString:@"reqtype" withString:strRequestType options:NSBackwardsSearch range:NSMakeRange(0,[tempsession length])]; NSString *tempresponseurl = [tempreqtype stringByReplacingOccurrencesOfString:@"responseurl" withString:strResponseURL options:NSBackwardsSearch range:NSMakeRange(0, [tempreqtype length])]; NSString *tempresponsevar = [tempresponseurl stringByReplacingOccurrencesOfString:@"responsevar" withString:strResponseVar options:NSBackwardsSearch range:NSMakeRange(0,[tempresponseurl length])]; NSData *data= [[NSString stringWithString:tempresponsevar] dataUsingEncoding:NSUTF8StringEncoding]; return data; } (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict { if([elementName isEqualToString:@"RESPVAL"]) currentAttribute = [NSMutableString string]; if([elementName isEqualToString:@"REASON"]) currentAttribute = [NSMutableString string]; if([elementName isEqualToString:@"COUNT"]) currentAttribute = [NSMutableString string]; if([elementName isEqualToString:@"CATNAME"]) currentAttribute = [NSMutableString string]; } (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName { if([elementName isEqualToString:@"RESPVAL"]) { [RESPVAR setString:currentAttribute]; //NSLog(@"\n Response VAR - %@", RESPVAR); } if([elementName isEqualToString:@"REASON"]) { [REASON setString:currentAttribute]; //NSLog(@"\n Reason - %@", REASON); } if([elementName isEqualToString:@"COUNT"]) { NSString *temp1 = [[NSString alloc] init]; temp1 = [temp1 stringByAppendingString:currentAttribute]; catCount = [temp1 intValue]; [temp1 release]; //NSLog(@"\n Cat Count - %d", catCount); } if([elementName isEqualToString:@"CATNAME"]) { [appDelegate.catListArray addObject:[NSString stringWithFormat:currentAttribute]]; //NSLog(@"%@", appDelegate.catListArray); } } (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string { if(self.currentAttribute) [self.currentAttribute setString:string]; } /* (void)viewWillAppear:(BOOL)animated { [super viewWillAppear:animated]; } */ /* (void)viewDidAppear:(BOOL)animated { [super viewDidAppear:animated]; } */ /* (void)viewWillDisappear:(BOOL)animated { [super viewWillDisappear:animated]; } */ /* (void)viewDidDisappear:(BOOL)animated { [super viewDidDisappear:animated]; } */ /* // Override to allow orientations other than the default portrait orientation. (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { // Return YES for supported orientations return (interfaceOrientation == UIInterfaceOrientationPortrait); } */ (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; // Releases the view if it doesn't have a superview // Release anything that's not essential, such as cached data } pragma mark Table view methods -(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView { return 1; } // Customize the number of rows in the table view. -(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { KlinnkAppDelegate *appDelegated = (KlinnkAppDelegate *)[[UIApplication sharedApplication] delegate]; return appDelegated.catListArray.count; } // Customize the appearance of table view cells. (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"Cell"; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; if (cell == nil) { cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:CellIdentifier] autorelease]; } // Set up the cell... AddBillerCategoryViewController *mbvc = (AddBillerCategoryViewController *)[appDelegate.catListArray objectAtIndex:indexPath.row]; [cell setText:mbvc.strOptions]; return cell; } (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { // Navigation logic may go here. Create and push another view controller. // AnotherViewController *anotherViewController = [[AnotherViewController alloc] initWithNibName:@"AnotherView" bundle:nil]; // [self.navigationController pushViewController:anotherViewController]; // [anotherViewController release]; gotOK = 0; int j = indexPath.row; appDelegate.catName = [[NSString alloc] init]; appDelegate.catName = [appDelegate.catName stringByAppendingString:[appDelegate.catListArray objectAtIndex:j]]; [[self navigationController] pushViewController:[[AddBillerListViewController alloc] init] animated:YES]; } /* // Override to support conditional editing of the table view. (BOOL)tableView:(UITableView *)tableView canEditRowAtIndexPath:(NSIndexPath *)indexPath { // Return NO if you do not want the specified item to be editable. return YES; } */ /* // Override to support editing the table view. (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath { if (editingStyle == UITableViewCellEditingStyleDelete) { // Delete the row from the data source [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:YES]; } else if (editingStyle == UITableViewCellEditingStyleInsert) { // Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view } } */ /* // Override to support rearranging the table view. (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)fromIndexPath toIndexPath:(NSIndexPath *)toIndexPath { } */ /* // Override to support conditional rearranging of the table view. (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath { // Return NO if you do not want the item to be re-orderable. return YES; } */ (void)dealloc { [REASON release]; [RESPVAR release]; [currentAttribute release]; [tbldata release]; [super dealloc]; } @end In the Above code .. numberOfSectionsInTableView ,i get error of obj-msg-send i have intialize the array catlist and even not released it anywhere still why i am getting this error please help me i am badly stuck' thanks in advacnce

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• Reuse Client java Socket in a Java Server

  - by user1394983

  I'm devoloping an Java server two control an android online game. It's possible save the client socket of myserversocket.accept() in a variable in Client class? This are very util because this way, server can communicate with client when server wants and no when client contact server. My actual code are: import java.io.IOException; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import java.net.ServerSocket; import java.net.Socket; import java.util.ArrayList; import java.util.UUID; import sal.app.shared.Packet; public class Server { private ArrayList<GameSession> games = new ArrayList<GameSession>(); private ArrayList<Client> pendent_clients = new ArrayList<Client>(); private Packet read_packet= new Packet(); private Packet sent_packet = new Packet(); private Socket clientSocket = null; public static void main(String[] args) throws ClassNotFoundException{ ServerSocket serverSocket = null; //DataInputStream dataInputStream = null; //DataOutputStream dataOutputStream = null; ObjectOutputStream oos=null; ObjectInputStream ois=null; Server myServer = new Server(); try { serverSocket = new ServerSocket(7777); System.out.println("Listening :7777"); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } while(true){ try { myServer.clientSocket = new Socket(); myServer.clientSocket = serverSocket.accept(); myServer.read_packet = new Packet(); myServer.sent_packet = new Packet(); oos = new ObjectOutputStream(myServer.clientSocket.getOutputStream()); ois = new ObjectInputStream(myServer.clientSocket.getInputStream()); //dataInputStream = new DataInputStream(clientSocket.getInputStream()); //dataOutputStream = new DataOutputStream(clientSocket.getOutputStream()); //System.out.println("ip: " + clientSocket.getInetAddress()); //System.out.println("message: " + ois.read()); //dataOutputStream.writeUTF("Hello!"); /*while ((myServer.read_packet = (Packet) ois.readObject()) != null) { myServer.handlePacket(myServer.read_packet); break; }*/ myServer.read_packet=(Packet) ois.readObject(); myServer.handlePacket(myServer.read_packet); //oos.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } finally{ if( myServer.clientSocket!= null){ /*try { //myServer.clientSocket.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); }*/ } /*if( ois!= null){ try { ois.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } if( oos!= null){ try { oos.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } }*/ } } } public void handlePacket(Packet hp) throws IOException { if(hp.getOpCode() == 1) { registPlayer(hp); } } public void registPlayer(Packet p) throws IOException { Client registClient = new Client(this.clientSocket); this.pendent_clients.add(registClient); if(pendent_clients.size() == 2) { initAGame(); } else { ObjectOutputStream out=null; Packet to_send = new Packet(); to_send.setOpCode(4); out = new ObjectOutputStream(registClient.getClientSocket().getOutputStream()); out.writeObject(to_send); } } public void initAGame() throws IOException { Client c1 = pendent_clients.get(0); Client c2 = pendent_clients.get(1); Packet to_send = new Packet(); ObjectOutputStream out=null; GameSession incomingGame = new GameSession(c1,c2); games.add(incomingGame); to_send.setGameId(incomingGame.getGameId()); to_send.setOpCode(5); out = new ObjectOutputStream(c1.getClientSocket().getOutputStream()); out.writeObject(to_send); out = new ObjectOutputStream(c2.getClientSocket().getOutputStream()); out.writeObject(to_send); pendent_clients.clear(); } public Client getClientById(UUID given_id) { for(GameSession gs: games) { if(gs.getClient1().getClientId().equals(given_id)) { return gs.getClient1(); } else if(gs.getClient2().getClientId().equals(given_id)) { return gs.getClient2(); } } return null; } } With this code i got this erros: java.net.SocketException: Broken pipe at java.net.SocketOutputStream.socketWrite0(Native Method) at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:92) at java.net.SocketOutputStream.write(SocketOutputStream.java:136) at java.io.ObjectOutputStream$BlockDataOutputStream.drain(ObjectOutputStream.java:1847) at java.io.ObjectOutputStream$BlockDataOutputStream.setBlockDataMode(ObjectOutputStream.java:1756) at java.io.ObjectOutputStream.writeNonProxyDesc(ObjectOutputStream.java:1257) at java.io.ObjectOutputStream.writeClassDesc(ObjectOutputStream.java:1211) at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1395) at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1158) at java.io.ObjectOutputStream.writeFatalException(ObjectOutputStream.java:1547) at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:333) at Server.initAGame(Server.java:146) at Server.registPlayer(Server.java:120) at Server.handlePacket(Server.java:106) at Server.main(Server.java:63) This error ocurre when second client connect and server try to send an Packet to previous client 1 in function initGame() in this code: out = new ObjectOutputStream(c1.getClientSocket().getOutputStream()); out.writeObject(to_send); my android code is this: package sal.app; import java.io.DataInputStream; import java.io.DataOutputStream; import java.io.IOException; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import java.net.Socket; import java.net.UnknownHostException; import sal.app.logic.DataBaseManager; import sal.app.shared.Packet; import android.app.Activity; import android.os.Bundle; import android.view.Window; import android.view.WindowManager; public class MultiPlayerWaitActivity extends Activity{ private DataBaseManager db; public void onCreate(Bundle savedInstanceState) { super.requestWindowFeature(Window.FEATURE_NO_TITLE); super.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN); super.onCreate(savedInstanceState); setContentView(R.layout.multiwaitlayout); db=DataBaseManager.getSalDatabase(this); db.teste(); try { db.createDataBase(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } Socket socket = null; ObjectOutputStream outputStream = null; ObjectInputStream inputStream = null; //System.out.println("dadadad"); try { socket = new Socket("192.168.1.4", 7777); //Game = new MultiPlayerGame(new ServerManager("192.168.1.66"),new Session(), new Player("")); outputStream = new ObjectOutputStream(socket.getOutputStream()); inputStream = new ObjectInputStream(socket.getInputStream()); //dataOutputStream.writeUTF(textOut.getText().toString()); //textIn.setText(dataInputStream.readUTF()); Packet p = new Packet(); Packet r = new Packet(); p.setOpCode(1); outputStream.writeObject(p); /*try { r=(Packet)inputStream.readObject(); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); }*/ //while(true){ //dataInputStream = new DataInputStream(clientSocket.getInputStream()); //dataOutputStream = new DataOutputStream(clientSocket.getOutputStream()); //System.out.println("ip: " + clientSocket.getInetAddress()); //System.out.println("message: " + ois.read()); //dataOutputStream.writeUTF("Hello!"); /*while ((r= (Packet) inputStream.readObject()) != null) { handPacket(r); break; }*/ r=(Packet) inputStream.readObject(); handPacket(r); //oos.close(); //} /*System.out.println(r.getOpCode()); if(r.getOpCode() == 5) { this.finish(); }*/ } catch (UnknownHostException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } /*finally{ if (socket != null){ try { socket.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } if (outputStream != null){ try { outputStream.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } if (inputStream != null){ try { inputStream.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }*/ //catch (ClassNotFoundException e) { // TODO Auto-generated catch block //e.printStackTrace(); //} catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } } public void handPacket(Packet hp) { if(hp.getOpCode() == 5) { this.finish(); } this.finish(); } } Regards

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• Struts2 Hibernate Login with User table and group table

  - by J2ME NewBiew

  My problem is, i have a table User and Table Group (this table use to authorization for user - it mean when user belong to a group like admin, they can login into admincp and other user belong to group member, they just only read and write and can not login into admincp) each user maybe belong to many groups and each group has been contain many users and they have relationship are many to many I use hibernate for persistence storage. and struts 2 to handle business logic. When i want to implement login action from Struts2 how can i get value of group member belong to ? to compare with value i want to know? Example I get user from username and password then get group from user class but i dont know how to get value of group user belong to it mean if user belong to Groupid is 1 and in group table , at column adminpermission is 1, that user can login into admincp, otherwise he can't my code: User.java /* * To change this template, choose Tools | Templates * and open the template in the editor. */ package org.dejavu.software.model; import java.io.Serializable; import java.util.Date; import java.util.HashSet; import java.util.Set; import javax.persistence.CascadeType; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.FetchType; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.JoinColumn; import javax.persistence.JoinTable; import javax.persistence.ManyToMany; import javax.persistence.Table; import javax.persistence.Temporal; /** * * @author Administrator */ @Entity @Table(name="User") public class User implements Serializable{ private static final long serialVersionUID = 2575677114183358003L; private Long userId; private String username; private String password; private String email; private Date DOB; private String address; private String city; private String country; private String avatar; private Set<Group> groups = new HashSet<Group>(0); @Column(name="dob") @Temporal(javax.persistence.TemporalType.DATE) public Date getDOB() { return DOB; } public void setDOB(Date DOB) { this.DOB = DOB; } @Column(name="address") public String getAddress() { return address; } public void setAddress(String address) { this.address = address; } @Column(name="city") public String getCity() { return city; } public void setCity(String city) { this.city = city; } @Column(name="country") public String getCountry() { return country; } public void setCountry(String country) { this.country = country; } @Column(name="email") public String getEmail() { return email; } public void setEmail(String email) { this.email = email; } @ManyToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL) @JoinTable(name="usergroup",joinColumns={@JoinColumn(name="userid")},inverseJoinColumns={@JoinColumn( name="groupid")}) public Set<Group> getGroups() { return groups; } public void setGroups(Set<Group> groups) { this.groups = groups; } @Column(name="password") public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } @Id @GeneratedValue @Column(name="iduser") public Long getUserId() { return userId; } public void setUserId(Long userId) { this.userId = userId; } @Column(name="username") public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } @Column(name="avatar") public String getAvatar() { return avatar; } public void setAvatar(String avatar) { this.avatar = avatar; } } Group.java /* * To change this template, choose Tools | Templates * and open the template in the editor. */ package org.dejavu.software.model; import java.io.Serializable; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.Table; /** * * @author Administrator */ @Entity @Table(name="Group") public class Group implements Serializable{ private static final long serialVersionUID = -2722005617166945195L; private Long idgroup; private String groupname; private String adminpermission; private String editpermission; private String modpermission; @Column(name="adminpermission") public String getAdminpermission() { return adminpermission; } public void setAdminpermission(String adminpermission) { this.adminpermission = adminpermission; } @Column(name="editpermission") public String getEditpermission() { return editpermission; } public void setEditpermission(String editpermission) { this.editpermission = editpermission; } @Column(name="groupname") public String getGroupname() { return groupname; } public void setGroupname(String groupname) { this.groupname = groupname; } @Id @GeneratedValue @Column (name="idgroup") public Long getIdgroup() { return idgroup; } public void setIdgroup(Long idgroup) { this.idgroup = idgroup; } @Column(name="modpermission") public String getModpermission() { return modpermission; } public void setModpermission(String modpermission) { this.modpermission = modpermission; } } UserDAO /* * To change this template, choose Tools | Templates * and open the template in the editor. */ package org.dejavu.software.dao; import java.util.List; import org.dejavu.software.model.User; import org.dejavu.software.util.HibernateUtil; import org.hibernate.Query; import org.hibernate.Session; /** * * @author Administrator */ public class UserDAO extends HibernateUtil{ public User addUser(User user){ Session session = HibernateUtil.getSessionFactory().getCurrentSession(); session.beginTransaction(); session.save(user); session.getTransaction().commit(); return user; } public List<User> getAllUser(){ Session session = HibernateUtil.getSessionFactory().getCurrentSession(); session.beginTransaction(); List<User> user = null; try { user = session.createQuery("from User").list(); } catch (Exception e) { e.printStackTrace(); session.getTransaction().rollback(); } session.getTransaction().commit(); return user; } public User checkUsernamePassword(String username, String password){ Session session = HibernateUtil.getSessionFactory().getCurrentSession(); session.beginTransaction(); User user = null; try { Query query = session.createQuery("from User where username = :name and password = :password"); query.setString("username", username); query.setString("password", password); user = (User) query.uniqueResult(); } catch (Exception e) { e.printStackTrace(); session.getTransaction().rollback(); } session.getTransaction().commit(); return user; } } AdminLoginAction /* * To change this template, choose Tools | Templates * and open the template in the editor. */ package org.dejavu.software.view; import com.opensymphony.xwork2.ActionSupport; import org.dejavu.software.dao.UserDAO; import org.dejavu.software.model.User; /** * * @author Administrator */ public class AdminLoginAction extends ActionSupport{ private User user; private String username,password; private String role; private UserDAO userDAO; public AdminLoginAction(){ userDAO = new UserDAO(); } @Override public String execute(){ return SUCCESS; } @Override public void validate(){ if(getUsername().length() == 0){ addFieldError("username", "Username is required"); }if(getPassword().length()==0){ addFieldError("password", getText("Password is required")); } } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public String getRole() { return role; } public void setRole(String role) { this.role = role; } public User getUser() { return user; } public void setUser(User user) { this.user = user; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } } other question. i saw some example about Login, i saw some developers use interceptor, im cant understand why they use it, and what benefit "Interceptor" will be taken for us? Thank You Very Much!

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• WPF TreeView MouseDown

  - by imekon

  I've got something like this in a TreeView: <DataTemplate x:Key="myTemplate"> <StackPanel MouseDown="OnItemMouseDown"> ... </StackPanel> </DataTemplate> Using this I get the mouse down events if I click on items in the stack panel. However... there seems to be another item behind the stack panel that is the TreeViewItem - it's very hard to hit, but not impossible, and that's when the problems start to occur. I had a go at handling PreviewMouseDown on TreeViewItem, however that seems to require e.Handled = false otherwise standard tree view behaviour stops working. Ok, Here's the source code... MainWindow.xaml <Window x:Class="WPFMultiSelectTree.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:local="clr-namespace:WPFMultiSelectTree" Title="Multiple Selection Tree" Height="300" Width="300"> <Window.Resources> <!-- Declare the classes that convert bool to Visibility --> <local:VisibilityConverter x:Key="visibilityConverter"/> <local:VisibilityInverter x:Key="visibilityInverter"/> <!-- Set the style for any tree view item --> <Style TargetType="TreeViewItem"> <Style.Triggers> <DataTrigger Binding="{Binding Selected}" Value="True"> <Setter Property="Background" Value="DarkBlue"/> <Setter Property="Foreground" Value="White"/> </DataTrigger> </Style.Triggers> <EventSetter Event="PreviewMouseDown" Handler="OnTreePreviewMouseDown"/> </Style> <!-- Declare a hierarchical data template for the tree view items --> <HierarchicalDataTemplate x:Key="RecursiveTemplate" ItemsSource="{Binding Children}"> <StackPanel Margin="2" Orientation="Horizontal" MouseDown="OnTreeMouseDown"> <Ellipse Width="12" Height="12" Fill="Green"/> <TextBlock Margin="2" Text="{Binding Name}" Visibility="{Binding Editing, Converter={StaticResource visibilityInverter}}"/> <TextBox Margin="2" Text="{Binding Name}" KeyDown="OnTextBoxKeyDown" IsVisibleChanged="OnTextBoxIsVisibleChanged" Visibility="{Binding Editing, Converter={StaticResource visibilityConverter}}"/> <TextBlock Margin="2" Text="{Binding Index, StringFormat=({0})}"/> </StackPanel> </HierarchicalDataTemplate> <!-- Declare a simple template for a list box --> <DataTemplate x:Key="ListTemplate"> <TextBlock Text="{Binding Name}"/> </DataTemplate> </Window.Resources> <Grid> <!-- Declare the rows in this grid --> <Grid.RowDefinitions> <RowDefinition Height="Auto"/> <RowDefinition/> <RowDefinition Height="Auto"/> <RowDefinition/> </Grid.RowDefinitions> <!-- The first header --> <TextBlock Grid.Row="0" Margin="5" Background="PowderBlue">Multiple selection tree view</TextBlock> <!-- The tree view --> <TreeView Name="m_tree" Margin="2" Grid.Row="1" ItemsSource="{Binding Children}" ItemTemplate="{StaticResource RecursiveTemplate}"/> <!-- The second header --> <TextBlock Grid.Row="2" Margin="5" Background="PowderBlue">The currently selected items in the tree</TextBlock> <!-- The list box --> <ListBox Name="m_list" Margin="2" Grid.Row="3" ItemsSource="{Binding .}" ItemTemplate="{StaticResource ListTemplate}"/> </Grid> </Window> MainWindow.xaml.cs /// <summary> /// Interaction logic for MainWindow.xaml /// </summary> public partial class MainWindow : Window { private Container m_root; private Container m_first; private ObservableCollection<Container> m_selection; private string m_current; /// <summary> /// Constructor /// </summary> public MainWindow() { InitializeComponent(); m_selection = new ObservableCollection<Container>(); m_root = new Container("root"); for (int parents = 0; parents < 50; parents++) { Container parent = new Container(String.Format("parent{0}", parents + 1)); for (int children = 0; children < 1000; children++) { parent.Add(new Container(String.Format("child{0}", children + 1))); } m_root.Add(parent); } m_tree.DataContext = m_root; m_list.DataContext = m_selection; m_first = null; } /// <summary> /// Has the shift key been pressed? /// </summary> private bool ShiftPressed { get { return Keyboard.IsKeyDown(Key.LeftShift) || Keyboard.IsKeyDown(Key.RightShift); } } /// <summary> /// Has the control key been pressed? /// </summary> private bool CtrlPressed { get { return Keyboard.IsKeyDown(Key.LeftCtrl) || Keyboard.IsKeyDown(Key.RightCtrl); } } /// <summary> /// Clear down the selection list /// </summary> private void DeselectAndClear() { foreach(Container container in m_selection) { container.Selected = false; } m_selection.Clear(); } /// <summary> /// Add the container to the list (if not already present), /// mark as selected /// </summary> /// <param name="container"></param> private void AddToSelection(Container container) { if (container == null) { return; } foreach (Container child in m_selection) { if (child == container) { return; } } container.Selected = true; m_selection.Add(container); } /// <summary> /// Remove container from list, mark as not selected /// </summary> /// <param name="container"></param> private void RemoveFromSelection(Container container) { m_selection.Remove(container); container.Selected = false; } /// <summary> /// Process single click on a tree item /// /// Normally just select an item /// /// SHIFT-Click extends selection /// CTRL-Click toggles a selection /// </summary> /// <param name="sender"></param> private void OnTreeSingleClick(object sender) { FrameworkElement element = sender as FrameworkElement; if (element != null) { Container container = element.DataContext as Container; if (container != null) { if (CtrlPressed) { if (container.Selected) { RemoveFromSelection(container); } else { AddToSelection(container); } } else if (ShiftPressed) { if (container.Parent == m_first.Parent) { if (container.Index < m_first.Index) { Container item = container; for (int i = container.Index; i < m_first.Index; i++) { AddToSelection(item); item = item.Next; if (item == null) { break; } } } else if (container.Index > m_first.Index) { Container item = m_first; for (int i = m_first.Index; i <= container.Index; i++) { AddToSelection(item); item = item.Next; if (item == null) { break; } } } } } else { DeselectAndClear(); m_first = container; AddToSelection(container); } } } } /// <summary> /// Process double click on tree item /// </summary> /// <param name="sender"></param> private void OnTreeDoubleClick(object sender) { FrameworkElement element = sender as FrameworkElement; if (element != null) { Container container = element.DataContext as Container; if (container != null) { container.Editing = true; m_current = container.Name; } } } /// <summary> /// Clicked on the stack panel in the tree view /// /// Double left click: /// /// Switch to editing mode (flips visibility of textblock and textbox) /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void OnTreeMouseDown(object sender, MouseButtonEventArgs e) { Debug.WriteLine("StackPanel mouse down"); switch(e.ChangedButton) { case MouseButton.Left: switch (e.ClickCount) { case 2: OnTreeDoubleClick(sender); e.Handled = true; break; } break; } } /// <summary> /// Clicked on tree view item in tree /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void OnTreePreviewMouseDown(object sender, MouseButtonEventArgs e) { Debug.WriteLine("TreeViewItem preview mouse down"); switch (e.ChangedButton) { case MouseButton.Left: switch (e.ClickCount) { case 1: { // We've had a single click on a tree view item // Unfortunately this is the WHOLE tree item, including the +/- // symbol to the left. The tree doesn't do a selection, so we // have to filter this out... MouseDevice device = e.Device as MouseDevice; Debug.WriteLine(String.Format("Tree item clicked on: {0}", device.DirectlyOver.GetType().ToString())); // This is bad. The whole point of WPF is for the code // not to know what the UI has - yet here we are testing for // it as a workaround. Sigh... if (device.DirectlyOver.GetType() != typeof(Path)) { OnTreeSingleClick(sender); } // Cannot say handled - if we do it stops the tree working! //e.Handled = true; } break; } break; } } /// <summary> /// Key press in text box /// /// Return key finishes editing /// Escape key finishes editing, restores original value (this doesn't work!) /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void OnTextBoxKeyDown(object sender, KeyEventArgs e) { switch(e.Key) { case Key.Return: { TextBox box = sender as TextBox; if (box != null) { Container container = box.DataContext as Container; if (container != null) { container.Editing = false; e.Handled = true; } } } break; case Key.Escape: { TextBox box = sender as TextBox; if (box != null) { Container container = box.DataContext as Container; if (container != null) { container.Editing = false; container.Name = m_current; e.Handled = true; } } } break; } } /// <summary> /// When text box becomes visible, grab focus and select all text in it. /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void OnTextBoxIsVisibleChanged(object sender, DependencyPropertyChangedEventArgs e) { bool visible = (bool)e.NewValue; if (visible) { TextBox box = sender as TextBox; if (box != null) { box.Focus(); box.SelectAll(); } } } } Here's the Container class public class Container : INotifyPropertyChanged { private string m_name; private ObservableCollection<Container> m_children; private Container m_parent; private bool m_selected; private bool m_editing; /// <summary> /// Constructor /// </summary> /// <param name="name">name of object</param> public Container(string name) { m_name = name; m_children = new ObservableCollection<Container>(); m_parent = null; m_selected = false; m_editing = false; } /// <summary> /// Name of object /// </summary> public string Name { get { return m_name; } set { if (m_name != value) { m_name = value; OnPropertyChanged("Name"); } } } /// <summary> /// Index of object in parent's children /// /// If there's no parent, the index is -1 /// </summary> public int Index { get { if (m_parent != null) { return m_parent.Children.IndexOf(this); } return -1; } } /// <summary> /// Get the next item, assuming this is parented /// /// Returns null if end of list reached, or no parent /// </summary> public Container Next { get { if (m_parent != null) { int index = Index + 1; if (index < m_parent.Children.Count) { return m_parent.Children[index]; } } return null; } } /// <summary> /// List of children /// </summary> public ObservableCollection<Container> Children { get { return m_children; } } /// <summary> /// Selected status /// </summary> public bool Selected { get { return m_selected; } set { if (m_selected != value) { m_selected = value; OnPropertyChanged("Selected"); } } } /// <summary> /// Editing status /// </summary> public bool Editing { get { return m_editing; } set { if (m_editing != value) { m_editing = value; OnPropertyChanged("Editing"); } } } /// <summary> /// Parent of this object /// </summary> public Container Parent { get { return m_parent; } set { m_parent = value; } } /// <summary> /// WPF Property Changed event /// </summary> public event PropertyChangedEventHandler PropertyChanged; /// <summary> /// Handler to inform WPF that a property has changed /// </summary> /// <param name="name"></param> private void OnPropertyChanged(string name) { if (PropertyChanged != null) { PropertyChanged(this, new PropertyChangedEventArgs(name)); } } /// <summary> /// Add a child to this container /// </summary> /// <param name="child"></param> public void Add(Container child) { m_children.Add(child); child.m_parent = this; } /// <summary> /// Remove a child from this container /// </summary> /// <param name="child"></param> public void Remove(Container child) { m_children.Remove(child); child.m_parent = null; } } The two classes VisibilityConverter and VisibilityInverter are implementations of IValueConverter that translates bool to Visibility. They make sure the TextBlock is displayed when not editing, and the TextBox is displayed when editing.

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• Is there a Telecommunications Reference Architecture?

  - by raul.goycoolea

  @font-face { font-family: "Arial"; }@font-face { font-family: "Courier New"; }@font-face { font-family: "Wingdings"; }@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpFirst, li.MsoListParagraphCxSpFirst, div.MsoListParagraphCxSpFirst { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpMiddle, li.MsoListParagraphCxSpMiddle, div.MsoListParagraphCxSpMiddle { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpLast, li.MsoListParagraphCxSpLast, div.MsoListParagraphCxSpLast { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; }ol { margin-bottom: 0cm; }ul { margin-bottom: 0cm; } Abstract   Reference architecture provides needed architectural information that can be provided in advance to an enterprise to enable consistent architectural best practices. Enterprise Reference Architecture helps business owners to actualize their strategies, vision, objectives, and principles. It evaluates the IT systems, based on Reference Architecture goals, principles, and standards. It helps to reduce IT costs by increasing functionality, availability, scalability, etc. Telecom Reference Architecture provides customers with the flexibility to view bundled service bills online with the provision of multiple services. It provides real-time, flexible billing and charging systems, to handle complex promotions, discounts, and settlements with multiple parties. This paper attempts to describe the Reference Architecture for the Telecom Enterprises. It lays the foundation for a Telecom Reference Architecture by articulating the requirements, drivers, and pitfalls for telecom service providers. It describes generic reference architecture for telecom enterprises and moves on to explain how to achieve Enterprise Reference Architecture by using SOA.   Introduction   A Reference Architecture provides a methodology, set of practices, template, and standards based on a set of successful solutions implemented earlier. These solutions have been generalized and structured for the depiction of both a logical and a physical architecture, based on the harvesting of a set of patterns that describe observations in a number of successful implementations. It helps as a reference for the various architectures that an enterprise can implement to solve various problems. It can be used as the starting point or the point of comparisons for various departments/business entities of a company, or for the various companies for an enterprise. It provides multiple views for multiple stakeholders.   Major artifacts of the Enterprise Reference Architecture are methodologies, standards, metadata, documents, design patterns, etc.   Purpose of Reference Architecture   In most cases, architects spend a lot of time researching, investigating, defining, and re-arguing architectural decisions. It is like reinventing the wheel as their peers in other organizations or even the same organization have already spent a lot of time and effort defining their own architectural practices. This prevents an organization from learning from its own experiences and applying that knowledge for increased effectiveness.   Reference architecture provides missing architectural information that can be provided in advance to project team members to enable consistent architectural best practices.   Enterprise Reference Architecture helps an enterprise to achieve the following at the abstract level:   ·       Reference architecture is more of a communication channel to an enterprise ·       Helps the business owners to accommodate to their strategies, vision, objectives, and principles. ·       Evaluates the IT systems based on Reference Architecture Principles ·       Reduces IT spending through increasing functionality, availability, scalability, etc ·       A Real-time Integration Model helps to reduce the latency of the data updates Is used to define a single source of Information ·       Provides a clear view on how to manage information and security ·       Defines the policy around the data ownership, product boundaries, etc. ·       Helps with cost optimization across project and solution portfolios by eliminating unused or duplicate investments and assets ·       Has a shorter implementation time and cost   Once the reference architecture is in place, the set of architectural principles, standards, reference models, and best practices ensure that the aligned investments have the greatest possible likelihood of success in both the near term and the long term (TCO).     Common pitfalls for Telecom Service Providers   Telecom Reference Architecture serves as the first step towards maturity for a telecom service provider. During the course of our assignments/experiences with telecom players, we have come across the following observations – Some of these indicate a lack of maturity of the telecom service provider:   ·       In markets that are growing and not so mature, it has been observed that telcos have a significant amount of in-house or home-grown applications. In some of these markets, the growth has been so rapid that IT has been unable to cope with business demands. Telcos have shown a tendency to come up with workarounds in their IT applications so as to meet business needs. ·       Even for core functions like provisioning or mediation, some telcos have tried to manage with home-grown applications. ·       Most of the applications do not have the required scalability or maintainability to sustain growth in volumes or functionality. ·       Applications face interoperability issues with other applications in the operator's landscape. Integrating a new application or network element requires considerable effort on the part of the other applications. ·       Application boundaries are not clear, and functionality that is not in the initial scope of that application gets pushed onto it. This results in the development of the multiple, small applications without proper boundaries. ·       Usage of Legacy OSS/BSS systems, poor Integration across Multiple COTS Products and Internal Systems. Most of the Integrations are developed on ad-hoc basis and Point-to-Point Integration. ·       Redundancy of the business functions in different applications • Fragmented data across the different applications and no integrated view of the strategic data • Lot of performance Issues due to the usage of the complex integration across OSS and BSS systems   However, this is where the maturity of the telecom industry as a whole can be of help. The collaborative efforts of telcos to overcome some of these problems have resulted in bodies like the TM Forum. They have come up with frameworks for business processes, data, applications, and technology for telecom service providers. These could be a good starting point for telcos to clean up their enterprise landscape.   Industry Trends in Telecom Reference Architecture   Telecom reference architectures are evolving rapidly because telcos are facing business and IT challenges.   “The reality is that there probably is no killer application, no silver bullet that the telcos can latch onto to carry them into a 21st Century.... Instead, there are probably hundreds – perhaps thousands – of niche applications.... And the only way to find which of these works for you is to try out lots of them, ramp up the ones that work, and discontinue the ones that fail.” – Martin Creaner President & CTO TM Forum.   The following trends have been observed in telecom reference architecture:   ·       Transformation of business structures to align with customer requirements ·       Adoption of more Internet-like technical architectures. The Web 2.0 concept is increasingly being used. ·       Virtualization of the traditional operations support system (OSS) ·       Adoption of SOA to support development of IP-based services ·       Adoption of frameworks like Service Delivery Platforms (SDPs) and IP Multimedia Subsystem ·       (IMS) to enable seamless deployment of various services over fixed and mobile networks ·       Replacement of in-house, customized, and stove-piped OSS/BSS with standards-based COTS products ·       Compliance with industry standards and frameworks like eTOM, SID, and TAM to enable seamless integration with other standards-based products   Drivers of Reference Architecture   The drivers of the Reference Architecture are Reference Architecture Goals, Principles, and Enterprise Vision and Telecom Transformation. The details are depicted below diagram. @font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoCaption, li.MsoCaption, div.MsoCaption { margin: 0cm 0cm 10pt; font-size: 9pt; font-family: "Times New Roman"; color: rgb(79, 129, 189); font-weight: bold; }div.Section1 { page: Section1; } Figure 1. Drivers for Reference Architecture @font-face { font-family: "Arial"; }@font-face { font-family: "Courier New"; }@font-face { font-family: "Wingdings"; }@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpFirst, li.MsoListParagraphCxSpFirst, div.MsoListParagraphCxSpFirst { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpMiddle, li.MsoListParagraphCxSpMiddle, div.MsoListParagraphCxSpMiddle { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpLast, li.MsoListParagraphCxSpLast, div.MsoListParagraphCxSpLast { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; }ol { margin-bottom: 0cm; }ul { margin-bottom: 0cm; } Today’s telecom reference architectures should seamlessly integrate traditional legacy-based applications and transition to next-generation network technologies (e.g., IP multimedia subsystems). This has resulted in new requirements for flexible, real-time billing and OSS/BSS systems and implications on the service provider’s organizational requirements and structure.   Telecom reference architectures are today expected to:   ·       Integrate voice, messaging, email and other VAS over fixed and mobile networks, back end systems ·       Be able to provision multiple services and service bundles • Deliver converged voice, video and data services ·       Leverage the existing Network Infrastructure ·       Provide real-time, flexible billing and charging systems to handle complex promotions, discounts, and settlements with multiple parties. ·       Support charging of advanced data services such as VoIP, On-Demand, Services (e.g.  Video), IMS/SIP Services, Mobile Money, Content Services and IPTV. ·       Help in faster deployment of new services • Serve as an effective platform for collaboration between network IT and business organizations ·       Harness the potential of converging technology, networks, devices and content to develop multimedia services and solutions of ever-increasing sophistication on a single Internet Protocol (IP) ·       Ensure better service delivery and zero revenue leakage through real-time balance and credit management ·       Lower operating costs to drive profitability   Enterprise Reference Architecture   The Enterprise Reference Architecture (RA) fills the gap between the concepts and vocabulary defined by the reference model and the implementation. Reference architecture provides detailed architectural information in a common format such that solutions can be repeatedly designed and deployed in a consistent, high-quality, supportable fashion. This paper attempts to describe the Reference Architecture for the Telecom Application Usage and how to achieve the Enterprise Level Reference Architecture using SOA.   • Telecom Reference Architecture • Enterprise SOA based Reference Architecture   Telecom Reference Architecture   Tele Management Forum’s New Generation Operations Systems and Software (NGOSS) is an architectural framework for organizing, integrating, and implementing telecom systems. NGOSS is a component-based framework consisting of the following elements:   ·       The enhanced Telecom Operations Map (eTOM) is a business process framework. ·       The Shared Information Data (SID) model provides a comprehensive information framework that may be specialized for the needs of a particular organization. ·       The Telecom Application Map (TAM) is an application framework to depict the functional footprint of applications, relative to the horizontal processes within eTOM. ·       The Technology Neutral Architecture (TNA) is an integrated framework. TNA is an architecture that is sustainable through technology changes.   NGOSS Architecture Standards are:   ·       Centralized data ·       Loosely coupled distributed systems ·       Application components/re-use  ·       A technology-neutral system framework with technology specific implementations ·       Interoperability to service provider data/processes ·       Allows more re-use of business components across multiple business scenarios ·       Workflow automation   The traditional operator systems architecture consists of four layers,   ·       Business Support System (BSS) layer, with focus toward customers and business partners. Manages order, subscriber, pricing, rating, and billing information. ·       Operations Support System (OSS) layer, built around product, service, and resource inventories. ·       Networks layer – consists of Network elements and 3rd Party Systems. ·       Integration Layer – to maximize application communication and overall solution flexibility.   Reference architecture for telecom enterprises is depicted below. @font-face { font-family: "Arial"; }@font-face { font-family: "Courier New"; }@font-face { font-family: "Wingdings"; }@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoCaption, li.MsoCaption, div.MsoCaption { margin: 0cm 0cm 10pt; font-size: 9pt; font-family: "Times New Roman"; color: rgb(79, 129, 189); font-weight: bold; }p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpFirst, li.MsoListParagraphCxSpFirst, div.MsoListParagraphCxSpFirst { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpMiddle, li.MsoListParagraphCxSpMiddle, div.MsoListParagraphCxSpMiddle { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpLast, li.MsoListParagraphCxSpLast, div.MsoListParagraphCxSpLast { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; }ol { margin-bottom: 0cm; }ul { margin-bottom: 0cm; } Figure 2. Telecom Reference Architecture   The major building blocks of any Telecom Service Provider architecture are as follows:   1. Customer Relationship Management   CRM encompasses the end-to-end lifecycle of the customer: customer initiation/acquisition, sales, ordering, and service activation, customer care and support, proactive campaigns, cross sell/up sell, and retention/loyalty.   CRM also includes the collection of customer information and its application to personalize, customize, and integrate delivery of service to a customer, as well as to identify opportunities for increasing the value of the customer to the enterprise.   The key functionalities related to Customer Relationship Management are   ·       Manage the end-to-end lifecycle of a customer request for products. ·       Create and manage customer profiles. ·       Manage all interactions with customers – inquiries, requests, and responses. ·       Provide updates to Billing and other south bound systems on customer/account related updates such as customer/ account creation, deletion, modification, request bills, final bill, duplicate bills, credit limits through Middleware. ·       Work with Order Management System, Product, and Service Management components within CRM. ·       Manage customer preferences – Involve all the touch points and channels to the customer, including contact center, retail stores, dealers, self service, and field service, as well as via any media (phone, face to face, web, mobile device, chat, email, SMS, mail, the customer's bill, etc.). ·       Support single interface for customer contact details, preferences, account details, offers, customer premise equipment, bill details, bill cycle details, and customer interactions.   CRM applications interact with customers through customer touch points like portals, point-of-sale terminals, interactive voice response systems, etc. The requests by customers are sent via fulfillment/provisioning to billing system for ordering processing.   2. Billing and Revenue Management   Billing and Revenue Management handles the collection of appropriate usage records and production of timely and accurate bills – for providing pre-bill usage information and billing to customers; for processing their payments; and for performing payment collections. In addition, it handles customer inquiries about bills, provides billing inquiry status, and is responsible for resolving billing problems to the customer's satisfaction in a timely manner. This process grouping also supports prepayment for services.   The key functionalities provided by these applications are   ·       To ensure that enterprise revenue is billed and invoices delivered appropriately to customers. ·       To manage customers’ billing accounts, process their payments, perform payment collections, and monitor the status of the account balance. ·       To ensure the timely and effective fulfillment of all customer bill inquiries and complaints. ·       Collect the usage records from mediation and ensure appropriate rating and discounting of all usage and pricing. ·       Support revenue sharing; split charging where usage is guided to an account different from the service consumer. ·       Support prepaid and post-paid rating. ·       Send notification on approach / exceeding the usage thresholds as enforced by the subscribed offer, and / or as setup by the customer. ·       Support prepaid, post paid, and hybrid (where some services are prepaid and the rest of the services post paid) customers and conversion from post paid to prepaid, and vice versa. ·       Support different billing function requirements like charge prorating, promotion, discount, adjustment, waiver, write-off, account receivable, GL Interface, late payment fee, credit control, dunning, account or service suspension, re-activation, expiry, termination, contract violation penalty, etc. ·       Initiate direct debit to collect payment against an invoice outstanding. ·       Send notification to Middleware on different events; for example, payment receipt, pre-suspension, threshold exceed, etc.   Billing systems typically get usage data from mediation systems for rating and billing. They get provisioning requests from order management systems and inquiries from CRM systems. Convergent and real-time billing systems can directly get usage details from network elements.   3. Mediation   Mediation systems transform/translate the Raw or Native Usage Data Records into a general format that is acceptable to billing for their rating purposes.   The following lists the high-level roles and responsibilities executed by the Mediation system in the end-to-end solution.   ·       Collect Usage Data Records from different data sources – like network elements, routers, servers – via different protocol and interfaces. ·       Process Usage Data Records – Mediation will process Usage Data Records as per the source format. ·       Validate Usage Data Records from each source. ·       Segregates Usage Data Records coming from each source to multiple, based on the segregation requirement of end Application. ·       Aggregates Usage Data Records based on the aggregation rule if any from different sources. ·       Consolidates multiple Usage Data Records from each source. ·       Delivers formatted Usage Data Records to different end application like Billing, Interconnect, Fraud Management, etc. ·       Generates audit trail for incoming Usage Data Records and keeps track of all the Usage Data Records at various stages of mediation process. ·       Checks duplicate Usage Data Records across files for a given time window.   4. Fulfillment   This area is responsible for providing customers with their requested products in a timely and correct manner. It translates the customer's business or personal need into a solution that can be delivered using the specific products in the enterprise's portfolio. This process informs the customers of the status of their purchase order, and ensures completion on time, as well as ensuring a delighted customer. These processes are responsible for accepting and issuing orders. They deal with pre-order feasibility determination, credit authorization, order issuance, order status and tracking, customer update on customer order activities, and customer notification on order completion. Order management and provisioning applications fall into this category.   The key functionalities provided by these applications are   ·       Issuing new customer orders, modifying open customer orders, or canceling open customer orders; ·       Verifying whether specific non-standard offerings sought by customers are feasible and supportable; ·       Checking the credit worthiness of customers as part of the customer order process; ·       Testing the completed offering to ensure it is working correctly; ·       Updating of the Customer Inventory Database to reflect that the specific product offering has been allocated, modified, or cancelled; ·       Assigning and tracking customer provisioning activities; ·       Managing customer provisioning jeopardy conditions; and ·       Reporting progress on customer orders and other processes to customer.   These applications typically get orders from CRM systems. They interact with network elements and billing systems for fulfillment of orders.   5. Enterprise Management   This process area includes those processes that manage enterprise-wide activities and needs, or have application within the enterprise as a whole. They encompass all business management processes that   ·       Are necessary to support the whole of the enterprise, including processes for financial management, legal management, regulatory management, process, cost, and quality management, etc.;   ·       Are responsible for setting corporate policies, strategies, and directions, and for providing guidelines and targets for the whole of the business, including strategy development and planning for areas, such as Enterprise Architecture, that are integral to the direction and development of the business;   ·       Occur throughout the enterprise, including processes for project management, performance assessments, cost assessments, etc.     (i) Enterprise Risk Management:   Enterprise Risk Management focuses on assuring that risks and threats to the enterprise value and/or reputation are identified, and appropriate controls are in place to minimize or eliminate the identified risks. The identified risks may be physical or logical/virtual. Successful risk management ensures that the enterprise can support its mission critical operations, processes, applications, and communications in the face of serious incidents such as security threats/violations and fraud attempts. Two key areas covered in Risk Management by telecom operators are:   ·       Revenue Assurance: Revenue assurance system will be responsible for identifying revenue loss scenarios across components/systems, and will help in rectifying the problems. The following lists the high-level roles and responsibilities executed by the Revenue Assurance system in the end-to-end solution. o   Identify all usage information dropped when networks are being upgraded. o   Interconnect bill verification. o   Identify where services are routinely provisioned but never billed. o   Identify poor sales policies that are intensifying collections problems. o   Find leakage where usage is sent to error bucket and never billed for. o   Find leakage where field service, CRM, and network build-out are not optimized.   ·       Fraud Management: Involves collecting data from different systems to identify abnormalities in traffic patterns, usage patterns, and subscription patterns to report suspicious activity that might suggest fraudulent usage of resources, resulting in revenue losses to the operator.   The key roles and responsibilities of the system component are as follows:   o   Fraud management system will capture and monitor high usage (over a certain threshold) in terms of duration, value, and number of calls for each subscriber. The threshold for each subscriber is decided by the system and fixed automatically. o   Fraud management will be able to detect the unauthorized access to services for certain subscribers. These subscribers may have been provided unauthorized services by employees. The component will raise the alert to the operator the very first time of such illegal calls or calls which are not billed. o   The solution will be to have an alarm management system that will deliver alarms to the operator/provider whenever it detects a fraud, thus minimizing fraud by catching it the first time it occurs. o   The Fraud Management system will be capable of interfacing with switches, mediation systems, and billing systems   (ii) Knowledge Management   This process focuses on knowledge management, technology research within the enterprise, and the evaluation of potential technology acquisitions.   Key responsibilities of knowledge base management are to   ·       Maintain knowledge base – Creation and updating of knowledge base on ongoing basis. ·       Search knowledge base – Search of knowledge base on keywords or category browse ·       Maintain metadata – Management of metadata on knowledge base to ensure effective management and search. ·       Run report generator. ·       Provide content – Add content to the knowledge base, e.g., user guides, operational manual, etc.   (iii) Document Management   It focuses on maintaining a repository of all electronic documents or images of paper documents relevant to the enterprise using a system.   (iv) Data Management   It manages data as a valuable resource for any enterprise. For telecom enterprises, the typical areas covered are Master Data Management, Data Warehousing, and Business Intelligence. It is also responsible for data governance, security, quality, and database management.   Key responsibilities of Data Management are   ·       Using ETL, extract the data from CRM, Billing, web content, ERP, campaign management, financial, network operations, asset management info, customer contact data, customer measures, benchmarks, process data, e.g., process inputs, outputs, and measures, into Enterprise Data Warehouse. ·       Management of data traceability with source, data related business rules/decisions, data quality, data cleansing data reconciliation, competitors data – storage for all the enterprise data (customer profiles, products, offers, revenues, etc.) ·       Get online update through night time replication or physical backup process at regular frequency. ·       Provide the data access to business intelligence and other systems for their analysis, report generation, and use.   (v) Business Intelligence   It uses the Enterprise Data to provide the various analysis and reports that contain prospects and analytics for customer retention, acquisition of new customers due to the offers, and SLAs. It will generate right and optimized plans – bolt-ons for the customers.   The following lists the high-level roles and responsibilities executed by the Business Intelligence system at the Enterprise Level:   ·       It will do Pattern analysis and reports problem. ·       It will do Data Analysis – Statistical analysis, data profiling, affinity analysis of data, customer segment wise usage patterns on offers, products, service and revenue generation against services and customer segments. ·       It will do Performance (business, system, and forecast) analysis, churn propensity, response time, and SLAs analysis. ·       It will support for online and offline analysis, and report drill down capability. ·       It will collect, store, and report various SLA data. ·       It will provide the necessary intelligence for marketing and working on campaigns, etc., with cost benefit analysis and predictions.   It will advise on customer promotions with additional services based on loyalty and credit history of customer   ·       It will Interface with Enterprise Data Management system for data to run reports and analysis tasks. It will interface with the campaign schedules, based on historical success evidence.   (vi) Stakeholder and External Relations Management   It manages the enterprise's relationship with stakeholders and outside entities. Stakeholders include shareholders, employee organizations, etc. Outside entities include regulators, local community, and unions. Some of the processes within this grouping are Shareholder Relations, External Affairs, Labor Relations, and Public Relations.   (vii) Enterprise Resource Planning   It is used to manage internal and external resources, including tangible assets, financial resources, materials, and human resources. Its purpose is to facilitate the flow of information between all business functions inside the boundaries of the enterprise and manage the connections to outside stakeholders. ERP systems consolidate all business operations into a uniform and enterprise wide system environment.   The key roles and responsibilities for Enterprise System are given below:   ·        It will handle responsibilities such as core accounting, financial, and management reporting. ·       It will interface with CRM for capturing customer account and details. ·       It will interface with billing to capture the billing revenue and other financial data. ·       It will be responsible for executing the dunning process. Billing will send the required feed to ERP for execution of dunning. ·       It will interface with the CRM and Billing through batch interfaces. Enterprise management systems are like horizontals in the enterprise and typically interact with all major telecom systems. E.g., an ERP system interacts with CRM, Fulfillment, and Billing systems for different kinds of data exchanges.   6. External Interfaces/Touch Points   The typical external parties are customers, suppliers/partners, employees, shareholders, and other stakeholders. External interactions from/to a Service Provider to other parties can be achieved by a variety of mechanisms, including:   ·       Exchange of emails or faxes ·       Call Centers ·       Web Portals ·       Business-to-Business (B2B) automated transactions   These applications provide an Internet technology driven interface to external parties to undertake a variety of business functions directly for themselves. These can provide fully or partially automated service to external parties through various touch points.   Typical characteristics of these touch points are   ·       Pre-integrated self-service system, including stand-alone web framework or integration front end with a portal engine ·       Self services layer exposing atomic web services/APIs for reuse by multiple systems across the architectural environment ·       Portlets driven connectivity exposing data and services interoperability through a portal engine or web application   These touch points mostly interact with the CRM systems for requests, inquiries, and responses.   7. Middleware   The component will be primarily responsible for integrating the different systems components under a common platform. It should provide a Standards-Based Platform for building Service Oriented Architecture and Composite Applications. The following lists the high-level roles and responsibilities executed by the Middleware component in the end-to-end solution.   ·       As an integration framework, covering to and fro interfaces ·       Provide a web service framework with service registry. ·       Support SOA framework with SOA service registry. ·       Each of the interfaces from / to Middleware to other components would handle data transformation, translation, and mapping of data points. ·       Receive data from the caller / activate and/or forward the data to the recipient system in XML format. ·       Use standard XML for data exchange. ·       Provide the response back to the service/call initiator. ·       Provide a tracking until the response completion. ·       Keep a store transitional data against each call/transaction. ·       Interface through Middleware to get any information that is possible and allowed from the existing systems to enterprise systems; e.g., customer profile and customer history, etc. ·       Provide the data in a common unified format to the SOA calls across systems, and follow the Enterprise Architecture directive. ·       Provide an audit trail for all transactions being handled by the component.   8. Network Elements   The term Network Element means a facility or equipment used in the provision of a telecommunications service. Such terms also includes features, functions, and capabilities that are provided by means of such facility or equipment, including subscriber numbers, databases, signaling systems, and information sufficient for billing and collection or used in the transmission, routing, or other provision of a telecommunications service.   Typical network elements in a GSM network are Home Location Register (HLR), Intelligent Network (IN), Mobile Switching Center (MSC), SMS Center (SMSC), and network elements for other value added services like Push-to-talk (PTT), Ring Back Tone (RBT), etc.   Network elements are invoked when subscribers use their telecom devices for any kind of usage. These elements generate usage data and pass it on to downstream systems like mediation and billing system for rating and billing. They also integrate with provisioning systems for order/service fulfillment.   9. 3rd Party Applications   3rd Party systems are applications like content providers, payment gateways, point of sale terminals, and databases/applications maintained by the Government.   Depending on applicability and the type of functionality provided by 3rd party applications, the integration with different telecom systems like CRM, provisioning, and billing will be done.   10. Service Delivery Platform   A service delivery platform (SDP) provides the architecture for the rapid deployment, provisioning, execution, management, and billing of value added telecom services. SDPs are based on the concept of SOA and layered architecture. They support the delivery of voice, data services, and content in network and device-independent fashion. They allow application developers to aggregate network capabilities, services, and sources of content. SDPs typically contain layers for web services exposure, service application development, and network abstraction.   SOA Reference Architecture   SOA concept is based on the principle of developing reusable business service and building applications by composing those services, instead of building monolithic applications in silos. It’s about bridging the gap between business and IT through a set of business-aligned IT services, using a set of design principles, patterns, and techniques.   In an SOA, resources are made available to participants in a value net, enterprise, line of business (typically spanning multiple applications within an enterprise or across multiple enterprises). It consists of a set of business-aligned IT services that collectively fulfill an organization’s business processes and goals. We can choreograph these services into composite applications and invoke them through standard protocols. SOA, apart from agility and reusability, enables:   ·       The business to specify processes as orchestrations of reusable services ·       Technology agnostic business design, with technology hidden behind service interface ·       A contractual-like interaction between business and IT, based on service SLAs ·       Accountability and governance, better aligned to business services ·       Applications interconnections untangling by allowing access only through service interfaces, reducing the daunting side effects of change ·       Reduced pressure to replace legacy and extended lifetime for legacy applications, through encapsulation in services   ·       A Cloud Computing paradigm, using web services technologies, that makes possible service outsourcing on an on-demand, utility-like, pay-per-usage basis   The following section represents the Reference Architecture of logical view for the Telecom Solution. The new custom built application needs to align with this logical architecture in the long run to achieve EA benefits.   Packaged implementation applications, such as ERP billing applications, need to expose their functions as service providers (as other applications consume) and interact with other applications as service consumers.   COT applications need to expose services through wrappers such as adapters to utilize existing resources and at the same time achieve Enterprise Architecture goal and objectives.   The following are the various layers for Enterprise level deployment of SOA. This diagram captures the abstract view of Enterprise SOA layers and important components of each layer. Layered architecture means decomposition of services such that most interactions occur between adjacent layers. However, there is no strict rule that top layers should not directly communicate with bottom layers.   The diagram below represents the important logical pieces that would result from overall SOA transformation. @font-face { font-family: "Arial"; }@font-face { font-family: "Courier New"; }@font-face { font-family: "Wingdings"; }@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoCaption, li.MsoCaption, div.MsoCaption { margin: 0cm 0cm 10pt; font-size: 9pt; font-family: "Times New Roman"; color: rgb(79, 129, 189); font-weight: bold; }p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpFirst, li.MsoListParagraphCxSpFirst, div.MsoListParagraphCxSpFirst { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpMiddle, li.MsoListParagraphCxSpMiddle, div.MsoListParagraphCxSpMiddle { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpLast, li.MsoListParagraphCxSpLast, div.MsoListParagraphCxSpLast { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; }ol { margin-bottom: 0cm; }ul { margin-bottom: 0cm; } Figure 3. Enterprise SOA Reference Architecture 1.          Operational System Layer: This layer consists of all packaged applications like CRM, ERP, custom built applications, COTS based applications like Billing, Revenue Management, Fulfilment, and the Enterprise databases that are essential and contribute directly or indirectly to the Enterprise OSS/BSS Transformation.   ERP holds the data of Asset Lifecycle Management, Supply Chain, and Advanced Procurement and Human Capital Management, etc.   CRM holds the data related to Order, Sales, and Marketing, Customer Care, Partner Relationship Management, Loyalty, etc.   Content Management handles Enterprise Search and Query. Billing application consists of the following components:   ·       Collections Management, Customer Billing Management, Invoices, Real-Time Rating, Discounting, and Applying of Charges ·       Enterprise databases will hold both the application and service data, whether structured or unstructured.   MDM - Master data majorly consists of Customer, Order, Product, and Service Data.     2.          Enterprise Component Layer:   This layer consists of the Application Services and Common Services that are responsible for realizing the functionality and maintaining the QoS of the exposed services. This layer uses container-based technologies such as application servers to implement the components, workload management, high availability, and load balancing.   Application Services: This Service Layer enables application, technology, and database abstraction so that the complex accessing logic is hidden from the other service layers. This is a basic service layer, which exposes application functionalities and data as reusable services. The three types of the Application access services are:   ·       Application Access Service: This Service Layer exposes application level functionalities as a reusable service between BSS to BSS and BSS to OSS integration. This layer is enabled using disparate technology such as Web Service, Integration Servers, and Adaptors, etc.   ·       Data Access Service: This Service Layer exposes application data services as a reusable reference data service. This is done via direct interaction with application data. and provides the federated query.   ·       Network Access Service: This Service Layer exposes provisioning layer as a reusable service from OSS to OSS integration. This integration service emphasizes the need for high performance, stateless process flows, and distributed design.   Common Services encompasses management of structured, semi-structured, and unstructured data such as information services, portal services, interaction services, infrastructure services, and security services, etc.   3.          Integration Layer:   This consists of service infrastructure components like service bus, service gateway for partner integration, service registry, service repository, and BPEL processor. Service bus will carry the service invocation payloads/messages between consumers and providers. The other important functions expected from it are itinerary based routing, distributed caching of routing information, transformations, and all qualities of service for messaging-like reliability, scalability, and availability, etc. Service registry will hold all contracts (wsdl) of services, and it helps developers to locate or discover service during design time or runtime.   • BPEL processor would be useful in orchestrating the services to compose a complex business scenario or process. • Workflow and business rules management are also required to support manual triggering of certain activities within business process. based on the rules setup and also the state machine information. Application, data, and service mediation layer typically forms the overall composite application development framework or SOA Framework.   4.          Business Process Layer: These are typically the intermediate services layer and represent Shared Business Process Services. At Enterprise Level, these services are from Customer Management, Order Management, Billing, Finance, and Asset Management application domains.   5.          Access Layer: This layer consists of portals for Enterprise and provides a single view of Enterprise information management and dashboard services.   6.          Channel Layer: This consists of various devices; applications that form part of extended enterprise; browsers through which users access the applications.   7.          Client Layer: This designates the different types of users accessing the enterprise applications. The type of user typically would be an important factor in determining the level of access to applications.   8.          Vertical pieces like management, monitoring, security, and development cut across all horizontal layers Management and monitoring involves all aspects of SOA-like services, SLAs, and other QoS lifecycle processes for both applications and services surrounding SOA governance.     9.          EA Governance, Reference Architecture, Roadmap, Principles, and Best Practices:   EA Governance is important in terms of providing the overall direction to SOA implementation within the enterprise. This involves board-level involvement, in addition to business and IT executives. At a high level, this involves managing the SOA projects implementation, managing SOA infrastructure, and controlling the entire effort through all fine-tuned IT processes in accordance with COBIT (Control Objectives for Information Technology).   Devising tools and techniques to promote reuse culture, and the SOA way of doing things needs competency centers to be established in addition to training the workforce to take up new roles that are suited to SOA journey.   Conclusions   Reference Architectures can serve as the basis for disparate architecture efforts throughout the organization, even if they use different tools and technologies. Reference architectures provide best practices and approaches in the independent way a vendor deals with technology and standards. Reference Architectures model the abstract architectural elements for an enterprise independent of the technologies, protocols, and products that are used to implement an SOA. Telecom enterprises today are facing significant business and technology challenges due to growing competition, a multitude of services, and convergence. Adopting architectural best practices could go a long way in meeting these challenges. The use of SOA-based architecture for communication to each of the external systems like Billing, CRM, etc., in OSS/BSS system has made the architecture very loosely coupled, with greater flexibility. Any change in the external systems would be absorbed at the Integration Layer without affecting the rest of the ecosystem. The use of a Business Process Management (BPM) tool makes the management and maintenance of the business processes easy, with better performance in terms of lead time, quality, and cost. Since the Architecture is based on standards, it will lower the cost of deploying and managing OSS/BSS applications over their lifecycles.

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• c# Truncate HTML safely for article summary

  - by WickedW

  Hi All, Does anyone have a c# variation of this? This is so I can take some html and display it without breaking as a summary lead in to an article? http://stackoverflow.com/questions/1193500/php-truncate-html-ignoring-tags Save me from reinventing the wheel! Thank you very much ---------- edit ------------------ Sorry, new here, and your right, should have phrased the question better, heres a bit more info I wish to take a html string and truncate it to a set number of words (or even char length) so I can then show the start of it as a summary (which then leads to the main article). I wish to preserve the html so I can show the links etc in preview. The main issue I have to solve is the fact that we may well end up with unclosed html tags if we truncate in the middle of 1 or more tags! The idea I have for solution is to a) truncate the html to N words (words better but chars ok) first (be sure not to stop in the middle of a tag and truncate a require attribute) b) work through the opened html tags in this truncated string (maybe stick them on stack as I go?) c) then work through the closing tags and ensure they match the ones on stack as I pop them off? d) if any open tags left on stack after this, then write them to end of truncated string and html should be good to go!!!! -- edit 12112009 Here is what I have bumbled together so far as a unittest file in VS2008, this 'may' help someone in future My hack attempts based on Jan code are at top for char version + word version (DISCLAIMER: this is dirty rough code!! on my part) I assume working with 'well-formed' HTML in all cases (but not necessarily a full document with a root node as per XML version) Abels XML version is at bottom, but not yet got round to fully getting tests to run on this yet (plus need to understand the code) ... I will update when I get chance to refine having trouble with posting code? is there no upload facility on stack? Thanks for all comments :) using System; using System.Collections.Generic; using System.Text.RegularExpressions; using System.Xml; using System.Xml.XPath; using Microsoft.VisualStudio.TestTools.UnitTesting; namespace PINET40TestProject { [TestClass] public class UtilityUnitTest { public static string TruncateHTMLSafeishChar(string text, int charCount) { bool inTag = false; int cntr = 0; int cntrContent = 0; // loop through html, counting only viewable content foreach (Char c in text) { if (cntrContent == charCount) break; cntr++; if (c == '<') { inTag = true; continue; } if (c == '>') { inTag = false; continue; } if (!inTag) cntrContent++; } string substr = text.Substring(0, cntr); //search for nonclosed tags MatchCollection openedTags = new Regex("<[^/](.|\n)*?>").Matches(substr); MatchCollection closedTags = new Regex("<[/](.|\n)*?>").Matches(substr); // create stack Stack<string> opentagsStack = new Stack<string>(); Stack<string> closedtagsStack = new Stack<string>(); // to be honest, this seemed like a good idea then I got lost along the way // so logic is probably hanging by a thread!! foreach (Match tag in openedTags) { string openedtag = tag.Value.Substring(1, tag.Value.Length - 2); // strip any attributes, sure we can use regex for this! if (openedtag.IndexOf(" ") >= 0) { openedtag = openedtag.Substring(0, openedtag.IndexOf(" ")); } // ignore brs as self-closed if (openedtag.Trim() != "br") { opentagsStack.Push(openedtag); } } foreach (Match tag in closedTags) { string closedtag = tag.Value.Substring(2, tag.Value.Length - 3); closedtagsStack.Push(closedtag); } if (closedtagsStack.Count < opentagsStack.Count) { while (opentagsStack.Count > 0) { string tagstr = opentagsStack.Pop(); if (closedtagsStack.Count == 0 || tagstr != closedtagsStack.Peek()) { substr += "</" + tagstr + ">"; } else { closedtagsStack.Pop(); } } } return substr; } public static string TruncateHTMLSafeishWord(string text, int wordCount) { bool inTag = false; int cntr = 0; int cntrWords = 0; Char lastc = ' '; // loop through html, counting only viewable content foreach (Char c in text) { if (cntrWords == wordCount) break; cntr++; if (c == '<') { inTag = true; continue; } if (c == '>') { inTag = false; continue; } if (!inTag) { // do not count double spaces, and a space not in a tag counts as a word if (c == 32 && lastc != 32) cntrWords++; } } string substr = text.Substring(0, cntr) + " ..."; //search for nonclosed tags MatchCollection openedTags = new Regex("<[^/](.|\n)*?>").Matches(substr); MatchCollection closedTags = new Regex("<[/](.|\n)*?>").Matches(substr); // create stack Stack<string> opentagsStack = new Stack<string>(); Stack<string> closedtagsStack = new Stack<string>(); foreach (Match tag in openedTags) { string openedtag = tag.Value.Substring(1, tag.Value.Length - 2); // strip any attributes, sure we can use regex for this! if (openedtag.IndexOf(" ") >= 0) { openedtag = openedtag.Substring(0, openedtag.IndexOf(" ")); } // ignore brs as self-closed if (openedtag.Trim() != "br") { opentagsStack.Push(openedtag); } } foreach (Match tag in closedTags) { string closedtag = tag.Value.Substring(2, tag.Value.Length - 3); closedtagsStack.Push(closedtag); } if (closedtagsStack.Count < opentagsStack.Count) { while (opentagsStack.Count > 0) { string tagstr = opentagsStack.Pop(); if (closedtagsStack.Count == 0 || tagstr != closedtagsStack.Peek()) { substr += "</" + tagstr + ">"; } else { closedtagsStack.Pop(); } } } return substr; } public static string TruncateHTMLSafeishCharXML(string text, int charCount) { // your data, probably comes from somewhere, or as params to a methodint XmlDocument xml = new XmlDocument(); xml.LoadXml(text); // create a navigator, this is our primary tool XPathNavigator navigator = xml.CreateNavigator(); XPathNavigator breakPoint = null; // find the text node we need: while (navigator.MoveToFollowing(XPathNodeType.Text)) { string lastText = navigator.Value.Substring(0, Math.Min(charCount, navigator.Value.Length)); charCount -= navigator.Value.Length; if (charCount <= 0) { // truncate the last text. Here goes your "search word boundary" code: navigator.SetValue(lastText); breakPoint = navigator.Clone(); break; } } // first remove text nodes, because Microsoft unfortunately merges them without asking while (navigator.MoveToFollowing(XPathNodeType.Text)) { if (navigator.ComparePosition(breakPoint) == XmlNodeOrder.After) { navigator.DeleteSelf(); } } // moves to parent, then move the rest navigator.MoveTo(breakPoint); while (navigator.MoveToFollowing(XPathNodeType.Element)) { if (navigator.ComparePosition(breakPoint) == XmlNodeOrder.After) { navigator.DeleteSelf(); } } // moves to parent // then remove *all* empty nodes to clean up (not necessary): // TODO, add empty elements like <br />, <img /> as exclusion navigator.MoveToRoot(); while (navigator.MoveToFollowing(XPathNodeType.Element)) { while (!navigator.HasChildren && (navigator.Value ?? "").Trim() == "") { navigator.DeleteSelf(); } } // moves to parent navigator.MoveToRoot(); return navigator.InnerXml; } [TestMethod] public void TestTruncateHTMLSafeish() { // Case where we just make it to start of HREF (so effectively an empty link) // 'simple' nested none attributed tags Assert.AreEqual(@"<h1>1234</h1><b><i>56789</i>012</b>", TruncateHTMLSafeishChar( @"<h1>1234</h1><b><i>56789</i>012345</b>", 12)); // In middle of a! Assert.AreEqual(@"<h1>1234</h1><a href=""testurl""><b>567</b></a>", TruncateHTMLSafeishChar( @"<h1>1234</h1><a href=""testurl""><b>5678</b></a><i><strong>some italic nested in string</strong></i>", 7)); // more Assert.AreEqual(@"<div><b><i><strong>1</strong></i></b></div>", TruncateHTMLSafeishChar( @"<div><b><i><strong>12</strong></i></b></div>", 1)); // br Assert.AreEqual(@"<h1>1 3 5</h1><br />6", TruncateHTMLSafeishChar( @"<h1>1 3 5</h1><br />678<br />", 6)); } [TestMethod] public void TestTruncateHTMLSafeishWord() { // zero case Assert.AreEqual(@" ...", TruncateHTMLSafeishWord( @"", 5)); // 'simple' nested none attributed tags Assert.AreEqual(@"<h1>one two <br /></h1><b><i>three ...</i></b>", TruncateHTMLSafeishWord( @"<h1>one two <br /></h1><b><i>three </i>four</b>", 3), "we have added ' ...' to end of summary"); // In middle of a! Assert.AreEqual(@"<h1>one two three </h1><a href=""testurl""><b class=""mrclass"">four ...</b></a>", TruncateHTMLSafeishWord( @"<h1>one two three </h1><a href=""testurl""><b class=""mrclass"">four five </b></a><i><strong>some italic nested in string</strong></i>", 4)); // start of h1 Assert.AreEqual(@"<h1>one two three ...</h1>", TruncateHTMLSafeishWord( @"<h1>one two three </h1><a href=""testurl""><b>four five </b></a><i><strong>some italic nested in string</strong></i>", 3)); // more than words available Assert.AreEqual(@"<h1>one two three </h1><a href=""testurl""><b>four five </b></a><i><strong>some italic nested in string</strong></i> ...", TruncateHTMLSafeishWord( @"<h1>one two three </h1><a href=""testurl""><b>four five </b></a><i><strong>some italic nested in string</strong></i>", 99)); } [TestMethod] public void TestTruncateHTMLSafeishWordXML() { // zero case Assert.AreEqual(@" ...", TruncateHTMLSafeishWord( @"", 5)); // 'simple' nested none attributed tags string output = TruncateHTMLSafeishCharXML( @"<body><h1>one two </h1><b><i>three </i>four</b></body>", 13); Assert.AreEqual(@"<body>\r\n <h1>one two </h1>\r\n <b>\r\n <i>three</i>\r\n </b>\r\n</body>", output, "XML version, no ... yet and addeds '\r\n + spaces?' to format document"); // In middle of a! Assert.AreEqual(@"<h1>one two three </h1><a href=""testurl""><b class=""mrclass"">four ...</b></a>", TruncateHTMLSafeishCharXML( @"<body><h1>one two three </h1><a href=""testurl""><b class=""mrclass"">four five </b></a><i><strong>some italic nested in string</strong></i></body>", 4)); // start of h1 Assert.AreEqual(@"<h1>one two three ...</h1>", TruncateHTMLSafeishCharXML( @"<h1>one two three </h1><a href=""testurl""><b>four five </b></a><i><strong>some italic nested in string</strong></i>", 3)); // more than words available Assert.AreEqual(@"<h1>one two three </h1><a href=""testurl""><b>four five </b></a><i><strong>some italic nested in string</strong></i> ...", TruncateHTMLSafeishCharXML( @"<h1>one two three </h1><a href=""testurl""><b>four five </b></a><i><strong>some italic nested in string</strong></i>", 99)); } } }

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• Hi, I have a C hashing routine which is behaving strangely?

  - by aks

  Hi, In this hashing routine: 1.) I am able to add strings. 2.) I am able to view my added strings. 3.) When i try to add a duplicate string, it throws me an error saying already present. 4.) But, when i try to delete the same string which is already present in hash table, then the lookup_routine calls hash function to get an index. At this time, it throws a different hash index to the one it was already added. Hence, my delete routine is failing? I am able to understand the reason why for same string, hash fucntion calculates a different index each time (whereas the same logic works in view hash table routine)? Can someone help me? This is the Output, i am getting: $ ./a Press 1 to add an element to the hashtable Press 2 to delete an element from the hashtable Press 3 to search the hashtable Press 4 to view the hashtable Press 5 to exit Please enter your choice: 1 Please enter the string :gaura enters in add_string DEBUG purpose in hash function: str passed = gaura Hashval returned in hash func= 1 hashval = 1 enters in lookup_string str in lookup_string = gaura DEBUG purpose in hash function: str passed = gaura Hashval returned in hash func= 1 hashval = 1 DEBUG ERROR :element not found in lookup string DEBUG Purpose NULL Inserting... DEBUG1 : enters here hashval = 1 String added successfully Press 1 to add an element to the hashtable Press 2 to delete an element from the hashtable Press 3 to search the hashtable Press 4 to view the hashtable Press 5 to exit Please enter your choice: 1 Please enter the string :ayu enters in add_string DEBUG purpose in hash function: str passed = ayu Hashval returned in hash func= 1 hashval = 1 enters in lookup_string str in lookup_string = ayu DEBUG purpose in hash function: str passed = ayu Hashval returned in hash func= 1 hashval = 1 returns NULL in lookup_string DEBUG Purpose NULL Inserting... DEBUG2 : enters here hashval = 1 String added successfully Press 1 to add an element to the hashtable Press 2 to delete an element from the hashtable Press 3 to search the hashtable Press 4 to view the hashtable Press 5 to exit Please enter your choice: 1 Please enter the string :gaurava enters in add_string DEBUG purpose in hash function: str passed = gaurava Hashval returned in hash func= 7 hashval = 7 enters in lookup_string str in lookup_string = gaurava DEBUG purpose in hash function: str passed = gaurava Hashval returned in hash func= 7 hashval = 7 DEBUG ERROR :element not found in lookup string DEBUG Purpose NULL Inserting... DEBUG1 : enters here hashval = 7 String added successfully Press 1 to add an element to the hashtable Press 2 to delete an element from the hashtable Press 3 to search the hashtable Press 4 to view the hashtable Press 5 to exit Please enter your choice: 4 Index : i = 1 String = gaura ayu Index : i = 7 String = gaurava Press 1 to add an element to the hashtable Press 2 to delete an element from the hashtable Press 3 to search the hashtable Press 4 to view the hashtable Press 5 to exit Please enter your choice: 2 Please enter the string you want to delete :gaura String entered = gaura enters in delete_string DEBUG purpose in hash function: str passed = gaura Hashval returned in hash func= 0 hashval = 0 enters in lookup_string str in lookup_string = gaura DEBUG purpose in hash function: str passed = gaura Hashval returned in hash func= 0 hashval = 0 DEBUG ERROR :element not found in lookup string DEBUG Purpose Item not present. So, cannot be deleted Item found in list: Deletion failed Press 1 to add an element to the hashtable Press 2 to delete an element from the hashtable Press 3 to search the hashtable Press 4 to view the hashtable Press 5 to exit Please enter your choice: My routine is pasted below: include include struct list { char *string; struct list *next; }; struct hash_table { int size; /* the size of the table */ struct list *table; / the table elements */ }; struct hash_table * hashtable = NULL; struct hash_table *create_hash_table(int size) { struct hash_table *new_table; int i; if (size<1) return NULL; /* invalid size for table */ /* Attempt to allocate memory for the table structure */ if ((new_table = malloc(sizeof(struct hash_table))) == NULL) { return NULL; } /* Attempt to allocate memory for the table itself */ if ((new_table->table = malloc(sizeof(struct list *) * size)) == NULL) { return NULL; } /* Initialize the elements of the table */ for(i=0; i<size; i++) new_table->table[i] = '\0'; /* Set the table's size */ new_table->size = size; return new_table; } unsigned int hash(struct hash_table *hashtable, char *str) { printf("\n DEBUG purpose in hash function:\n"); printf("\n str passed = %s", str); unsigned int hashval = 0; int i = 0; for(; *str != '\0'; str++) { hashval += str[i]; i++; } hashval = hashval % 10; printf("\n Hashval returned in hash func= %d", hashval); return hashval; } struct list *lookup_string(struct hash_table *hashtable, char *str) { printf("\n enters in lookup_string \n"); printf("\n str in lookup_string = %s",str); struct list * new_list; unsigned int hashval = hash(hashtable, str); printf("\n hashval = %d \n", hashval); if(hashtable->table[hashval] == NULL) { printf("\n DEBUG ERROR :element not found in lookup string \n"); return NULL; } /* Go to the correct list based on the hash value and see if str is * in the list. If it is, return return a pointer to the list element. * If it isn't, the item isn't in the table, so return NULL. */ for(new_list = hashtable->table[hashval]; new_list != NULL;new_list = new_list->next) { if (strcmp(str, new_list->string) == 0) return new_list; } printf("\n returns NULL in lookup_string \n"); return NULL; } int add_string(struct hash_table *hashtable, char *str) { printf("\n enters in add_string \n"); struct list *new_list; struct list *current_list; unsigned int hashval = hash(hashtable, str); printf("\n hashval = %d", hashval); /* Attempt to allocate memory for list */ if ((new_list = malloc(sizeof(struct list))) == NULL) { printf("\n enters here \n"); return 1; } /* Does item already exist? */ current_list = lookup_string(hashtable, str); if (current_list == NULL) { printf("\n DEBUG Purpose \n"); printf("\n NULL \n"); } /* item already exists, don't insert it again. */ if (current_list != NULL) { printf("\n Item already present...\n"); return 2; } /* Insert into list */ printf("\n Inserting...\n"); new_list->string = strdup(str); new_list->next = NULL; //new_list->next = hashtable->table[hashval]; if(hashtable->table[hashval] == NULL) { printf("\n DEBUG1 : enters here \n"); printf("\n hashval = %d", hashval); hashtable->table[hashval] = new_list; } else { printf("\n DEBUG2 : enters here \n"); printf("\n hashval = %d", hashval); struct list * temp_list = hashtable->table[hashval]; while(temp_list->next!=NULL) temp_list = temp_list->next; temp_list->next = new_list; // hashtable->table[hashval] = new_list; } return 0; } int delete_string(struct hash_table *hashtable, char *str) { printf("\n enters in delete_string \n"); struct list *new_list; struct list *current_list; unsigned int hashval = hash(hashtable, str); printf("\n hashval = %d", hashval); /* Does item already exist? */ current_list = lookup_string(hashtable, str); if (current_list == NULL) { printf("\n DEBUG Purpose \n"); printf("\n Item not present. So, cannot be deleted \n"); return 1; } /* item exists, delete it. */ if (current_list != NULL) { struct list * temp = hashtable->table[hashval]; if(strcmp(temp->string,str) == 0) { if(temp->next == NULL) { hashtable->table[hashval] = NULL; free(temp); } else { hashtable->table[hashval] = temp->next; free(temp); } } else { struct list * temp1; while(temp->next != NULL) { temp1 = temp; if(strcmp(temp->string, str) == 0) { break; } else { temp = temp->next; } } if(temp->next == NULL) { temp1->next = NULL; free(temp); } else { temp1->next = temp->next; free(temp); } } } return 0; } void free_table(struct hash_table *hashtable) { int i; struct list *new_list, *temp_list; if (hashtable==NULL) return; /* Free the memory for every item in the table, including the * strings themselves. */ for(i=0; i<hashtable->size; i++) { new_list = hashtable->table[i]; while(new_list!=NULL) { temp_list = new_list; new_list = new_list->next; free(temp_list->string); free(temp_list); } } /* Free the table itself */ free(hashtable->table); free(hashtable); } void view_hashtable(struct hash_table * hashtable) { int i = 0; if(hashtable == NULL) return; for(i =0; i < hashtable->size; i++) { if((hashtable->table[i] == 0) || (strcmp(hashtable->table[i]->string, "*") == 0)) { continue; } printf(" Index : i = %d\t String = %s",i, hashtable->table[i]->string); struct list * temp = hashtable->table[i]->next; while(temp != NULL) { printf("\t %s",temp->string); temp = temp->next; } printf("\n"); } } int main() { hashtable = create_hash_table(10); if(hashtable == NULL) { printf("\n Memory allocation failure during creation of hash table \n"); return 0; } int flag = 1; while(flag) { int choice; printf("\n Press 1 to add an element to the hashtable\n"); printf("\n Press 2 to delete an element from the hashtable\n"); printf("\n Press 3 to search the hashtable\n"); printf("\n Press 4 to view the hashtable\n"); printf("\n Press 5 to exit \n"); printf("\n Please enter your choice: "); scanf("%d",&choice); if(choice == 5) flag = 0; else if(choice == 1) { char str[20]; printf("\n Please enter the string :"); scanf("%s",&str); int i; i = add_string(hashtable,str); if(i == 1) { printf("\n Memory allocation failure:Choice 1 \n"); return 0; } else if(i == 2) { printf("\n String already prsent in hash table : Couldnot add it again\n"); return 0; } else { printf("\n String added successfully \n"); } } else if(choice == 2) { int i; struct list * temp_list; char str[20]; printf("\n Please enter the string you want to delete :"); scanf("%s",&str); printf("\n String entered = %s", str); i = delete_string(hashtable,str); if(i == 0) { printf("\n Item found in list: Deletion success \n"); } else printf("\n Item found in list: Deletion failed \n"); } else if(choice == 3) { struct list * temp_list; char str[20]; printf("\n Please enter the string :"); scanf("%s",&str); temp_list = lookup_string(hashtable,str); if(!temp_list) { printf("\n Item not found in list: Deletion failed \n"); return 0; } printf("\n Item found: Present in Hash Table \n"); } else if(choice == 4) { view_hashtable(hashtable); } else if(choice == 5) { printf("\n Exiting ...."); return 0; } else printf("\n Invalid choice:"); }; free_table(hashtable); return 0; }

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