nidhinzz own - Page 704

Using my custom colormap in Java for images

- by John

Hi everyone! I've got a question concering a colormapping via index. I tried this code found on http://www.podgoretsky.pri.ee/ftp/Docs/Java/Tricks%20of%20the%20Java%20Programming%20Gurus/ch12.htm // Gradient.java // Imports import java.applet.Applet; import java.awt.; import java.awt.image.; public class Gradient extends Applet { final int colors = 32; final int width = 200; final int height = 200; Image img; public void init() { // Create the color map byte[] rbmap = new byte[colors]; byte[] gmap = new byte[colors]; for (int i = 0; i < colors; i++) gmap[i] = (byte)((i * 255) / (colors - 1)); // Create the color model int bits = (int)Math.ceil(Math.log(colors) / Math.log(2)); IndexColorModel model = new IndexColorModel(bits, colors, rbmap, gmap, rbmap); // Create the pixels int pixels[] = new int[width * height]; int index = 0; for (int y = 0; y < height; y++) for (int x = 0; x < width; x++) pixels[index++] = (x * colors) / width; // Create the image img = createImage(new MemoryImageSource(width, height, model, pixels, 0, width)); } public void paint(Graphics g) { g.drawImage(img, 0, 0, this); } } It worked great but I tried to load a custom image jpeg mapped on my own colormap but it didnt work right. I saw only a bunch of green and blue pixels drawn on a white background. My custom color map method here: public void inintByteArrays() { double[][] c = // basic color map { { 0.0000, 0.0000, 0.5625 }, { 0.0000, 0.0000, 0.6250 }, { 0.0000, 0.0000, 0.6875 }, { 0.0000, 0.0000, 0.6875 }, { 0.0000, 0.0000, 0.7500 }, { 0.0000, 0.0000, 0.8125 }, { 0.0000, 0.0000, 0.8750 }, { 0.0000, 0.0000, 0.9375 }, { 0.0000, 0.0000, 1.0000 }, { 0.0000, 0.0625, 1.0000 }, { 0.0000, 0.1250, 1.0000 }, { 0.0000, 0.1875, 1.0000 }, { 0.0000, 0.2500, 1.0000 }, { 0.0000, 0.3125, 1.0000 }, { 0.0000, 0.3750, 1.0000 }, { 0.0000, 0.4375, 1.0000 }, { 0.0000, 0.5000, 1.0000 }, { 0.0000, 0.5625, 1.0000 }, { 0.0000, 0.6250, 1.0000 }, { 0.0000, 0.6875, 1.0000 }, { 0.0000, 0.7500, 1.0000 }, { 0.0000, 0.8125, 1.0000 }, { 0.0000, 0.8750, 1.0000 }, { 0.0000, 0.9375, 1.0000 }, { 0.0000, 1.0000, 1.0000 }, { 0.0625, 1.0000, 0.9375 }, { 0.1250, 1.0000, 0.8750 }, { 0.1875, 1.0000, 0.8125 }, { 0.2500, 1.0000, 0.7500 }, { 0.3125, 1.0000, 0.6875 }, { 0.3750, 1.0000, 0.6250 }, { 0.4375, 1.0000, 0.5625 }, { 0.5000, 1.0000, 0.5000 }, { 0.5625, 1.0000, 0.4375 }, { 0.6250, 1.0000, 0.3750 }, { 0.6875, 1.0000, 0.3125 }, { 0.7500, 1.0000, 0.2500 }, { 0.8125, 1.0000, 0.1875 }, { 0.8750, 1.0000, 0.1250 }, { 0.9375, 1.0000, 0.0625 }, { 1.0000, 1.0000, 0.0000 }, { 1.0000, 0.9375, 0.0000 }, { 1.0000, 0.8750, 0.0000 }, { 1.0000, 0.8125, 0.0000 }, { 1.0000, 0.7500, 0.0000 }, { 1.0000, 0.6875, 0.0000 }, { 1.0000, 0.6250, 0.0000 }, { 1.0000, 0.5625, 0.0000 }, { 1.0000, 0.5000, 0.0000 }, { 1.0000, 0.4375, 0.0000 }, { 1.0000, 0.3750, 0.0000 }, { 1.0000, 0.3125, 0.0000 }, { 1.0000, 0.2500, 0.0000 }, { 1.0000, 0.1875, 0.0000 }, { 1.0000, 0.1250, 0.0000 }, { 1.0000, 0.0625, 0.0000 }, { 1.0000, 0.0000, 0.0000 }, { 0.9375, 0.0000, 0.0000 }, { 0.8750, 0.0000, 0.0000 }, { 0.8125, 0.0000, 0.0000 }, { 0.7500, 0.0000, 0.0000 }, { 0.6875, 0.0000, 0.0000 }, { 0.6250, 0.0000, 0.0000 }, { 0.5625, 0.0000, 0.0000 }, { 0.5000, 0.0000, 0.0000 } }; for (int i = 0; i < c.length; i++) { for (int j = 0; j < c[i].length; j++) { if (j == 0) r[i] = (byte) ((byte) c[i][j]*255); if (j == 1) g[i] = (byte) ((byte) c[i][j]*255); if (j == 2) b[i] = (byte) ((byte) c[i][j]*255); } } My question is how I can use my colormap for any image I want to load and map in the right way. Thank you very much! Greetings, protein1.

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LINQ-like or SQL-like DSL for end-users to run queries to select (not modify) data?

- by Mark Rushakoff

For a utility I'm working on, the client would like to be able to generate graphic reports on the data that has been collected. I can already generate a couple canned graphs (using ZedGraph, which is a very nice library); however, the utility would be much more flexible if the graphs were more programmable or configurable by the end-user. TLDR version I want users to be able to use something like SQL to safely extract and select data from a List of objects that I provide and can describe. What free tools or libraries will help me accomplish this? Full version I've given thought to using IronPython, IronRuby, and LuaInterface, but frankly they're all a bit overpowered for what I want to do. My classes are fairly simple, along the lines of: class Person: string Name; int HeightInCm; DateTime BirthDate; Weight[] WeighIns; class Weight: int WeightInKg; DateTime Date; Person Owner; (exact classes have been changed to protect the innocent). To come up with the data for the graph, the user will choose whether it's a bar graph, scatter plot, etc., and then to actually obtain the data, I would like to obtain some kind of List from the user simply entering something SQL-ish along the lines of SELECT Name, AVG(WeighIns) FROM People SELECT WeightInKg, Owner.HeightInCm FROM Weights And as a bonus, it would be nice if you could actually do operations as well: SELECT WeightInKg, (Date - Owner.BirthDate) AS Age FROM Weights The DSL doesn't have to be compliant SQL in any way; it doesn't even have to resemble SQL, but I can't think of a more efficient descriptive language for the task. I'm fine filling in blanks; I don't expect a library to do everything for me. What I would expect to exist (but haven't been able to find in any way, shape, or form) is something like Fluent NHibernate (which I am already using in the project) where I can declare a mapping, something like var personRequest = Request<Person>(); personRequest.Item("Name", (p => p.Name)); personRequest.Item("HeightInCm", (p => p.HeightInCm)); personRequest.Item("HeightInInches", (p => p.HeightInCm * CM_TO_INCHES)); // ... var weightRequest = Request<Weight>(); weightRequest.Item("Owner", (w => w.Owner), personRequest); // Indicate a chain to personRequest // ... var people = Table<Person>("People", GetPeopleFromDatabase()); var weights = Table<Weight>("Weights", GetWeightsFromDatabase()); // ... TryRunQuery(userInputQuery); LINQ is so close to what I want to do, but AFAIK there's no way to sandbox it. I don't want to expose any unnecessary functionality to the end user; meaning I don't want the user to be able to send in and process: from p in people select (p => { System.IO.File.Delete("C:\\something\\important"); return p.Name }) So does anyone know of any free .NET libraries that allow something like what I've described above? Or is there some way to sandbox LINQ? cs-script is close too, but it doesn't seem to offer sandboxing yet either. I'd be hesitant to expose the NHibernate interface either, as the user should have a read-only view of the data at this point in the usage. I'm using C# 3.5, and pure .NET solutions would be preferred. The bottom line is that I'm really trying to avoid writing my own parser for a subset of SQL that would only apply to this single project.

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Delaying execution of Javascript function relative to Google Maps / geoxml3 parser?

- by Terra Fimeira

I'm working on a implementing a Google map on a website with our own tiles overlays and KML elements. I've been previously requested to create code so that, for instance, when the page is loaded from a specific URL, it would initialize with one of the tile overlays already enabled. Recently, I've been requested to do the same for the buildings which are outlined by KML elements so that, arriving at the page with a specific URL, it would automatically zoom, center, and display information on the building. However, while starting with the tile overlays work, the building KML does not. After doing some testing, I've determined that when the code which checks the URL executes, the page is still loading the KML elements and thus do not exist for the code to compare to or use: Code for evaluating URL (placed at the end of onLoad="initialize()") function urlClick() { var currentURL = window.location.href; //Retrieve page URL var URLpiece = currentURL.slice(-6); //pull the last 6 digits (for testing) if (URLpiece === "access") { //If the resulting string is "access": access_click(); //Display accessibility overlay } else if (URLpiece === "middle") { //Else if the string is "middle": facetClick('Middle College'); //Click on building "Middle College" }; }; facetClick(); function facetClick(name) { //Convert building name to building ID. for (var i = 0; i < active.placemarks.length; i++) { if (active.placemarks[i].name === name) { sideClick(i) //Click building whose id matches "Middle College" }; }; }; Firebug Console Error active is null for (var i = 0; i < active.placemarks.length; i++) { active.placemarks is which KML elements are loaded on the page, and being null, means no KML has been loaded yet. In short, I have a mistiming and I can't seem to find a suitable place to place the URL code to execute after the KMl has loaded. As noted above, I placed it at the end of onLoad="initialize()", but it would appear that, instead of waiting for the KML to completely load earlier in the function, the remainder of the function is executed: onLoad="initialize()" information(); //Use the buttons variables inital state to set up description buttons(); //and button state button_hover(0); //and button description to neutral. //Create and arrange the Google Map. //Create basic tile overlays. //Set up parser to work with KML elements. myParser = new geoXML3.parser({ //Parser: Takes KML and converts to JS. map: map, //Applies parsed KML to the map singleInfoWindow: true, afterParse: useTheData //Allows us to use the parsed KML in a function }); myParser.parse(['/maps/kml/shapes.kml','/maps/kml/shapes_hidden.kml']); google.maps.event.addListener(map, 'maptypeid_changed', function() { autoOverlay(); }); //Create other tile overlays to appear over KML elements. urlClick(); I suspect one my issues lies in using the geoxml3 parser (http://code.google.com/p/geoxml3/) which converts our KML files to Javascript. While the page has completed loading all of the elements, the map on the page is still loading, including the KML elements. I have also tried placing urlClick() in the parser itself in various places which appear to execute after all the shapes have been parsed, but I've had no success there either. While I've been intending to strip out the parser, I would like to know if there is any way of executing the "urlClick" after the parser has returned the KML shapes. Ideally, I don't want to use an arbitrary means of defining a time to wait, such as "wait 3 seconds, and go", as my various browsers all load the page at different times; rather, I'm looking for some way to say "when the parser is done, execute" or "when the Google map is completely loaded, execute" or perhaps even "hold until the parser is complete before advancing to urlClick".

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How to determine if CNF formula is satisfiable in Scheme?

- by JJBIRAN

Program a SCHEME function sat that takes one argument, a CNF formula represented as above. If we had evaluated (define cnf '((a (not b) c) (a (not b) (not d)) (b d))) then evaluating (sat cnf) would return #t, whereas (sat '((a) (not a))) would return (). You should have following two functions to work: (define comp (lambda (lit) ; This function takes a literal as argument and returns the complement literal as the returning value. Examples: (comp 'a) = (not a), and (comp '(not b)) = b. (define consistent (lambda (lit path) This function takes a literal and a list of literals as arguments, and returns #t whenever the complement of the first argument is not a member of the list represented by the 2nd argument; () otherwise. . Now for the sat function. The real searching involves the list of clauses (the CNF formula) and the path that has currently been developed. The sat function should merely invoke the real "workhorse" function, which will have 2 arguments, the current path and the clause list. In the initial call, the current path is of course empty. Hints on sat. (Ignore these at your own risk!) (define sat (lambda (clauselist) ; invoke satpath (define satpath (lambda (path clauselist) ; just returns #t or () ; base cases: ; if we're out of clauses, what then? ; if there are no literals to choose in the 1st clause, what then? ; ; then in general: ; if the 1st literal in the 1st clause is consistent with the ; current path, and if << returns #t, ; then return #t. ; ; if the 1st literal didn't work, then search << ; the CNF formula in which the 1st clause doesn't have that literal Don't make this too hard. My program is a few functions averaging about 2-8 lines each. SCHEME is consise and elegant! The following expressions may help you to test your programs. All but cnf4 are satisfiable. By including them along with your function definitions, the functions themselves are automatically tested and results displayed when the file is loaded. (define cnf1 '((a b c) (c d) (e)) ) (define cnf2 '((a c) (c))) (define cnf3 '((d e) (a))) (define cnf4 '( (a b) (a (not b)) ((not a) b) ((not a) (not b)) ) ) (define cnf5 '((d a) (d b c) ((not a) (not d)) (e (not d)) ((not b)) ((not d) (not e)))) (define cnf6 '((d a) (d b c) ((not a) (not d) (not c)) (e (not c)) ((not b)) ((not d) (not e)))) (write-string "(sat cnf1) ") (write (sat cnf1)) (newline) (write-string "(sat cnf2) ") (write (sat cnf2)) (newline) (write-string "(sat cnf3) ") (write (sat cnf3)) (newline) (write-string "(sat cnf4) ") (write (sat cnf4)) (newline) (write-string "(sat cnf5) ") (write (sat cnf5)) (newline)

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Trying to packetize TCP with non-blocking IO is hard! Am I doing something wrong?

- by Ricket

Oh how I wish TCP was packet-based like UDP is! But alas, that's not the case, so I'm trying to implement my own packet layer. Here's the chain of events so far (ignoring writing packets) Oh, and my Packets are very simply structured: two unsigned bytes for length, and then byte[length] data. (I can't imagine if they were any more complex, I'd be up to my ears in if statements!) Server is in an infinite loop, accepting connections and adding them to a list of Connections. PacketGatherer (another thread) uses a Selector to figure out which Connection.SocketChannels are ready for reading. It loops over the results and tells each Connection to read(). Each Connection has a partial IncomingPacket and a list of Packets which have been fully read and are waiting to be processed. On read(): Tell the partial IncomingPacket to read more data. (IncomingPacket.readData below) If it's done reading (IncomingPacket.complete()), make a Packet from it and stick the Packet into the list waiting to be processed and then replace it with a new IncomingPacket. There are a couple problems with this. First, only one packet is being read at a time. If the IncomingPacket needs only one more byte, then only one byte is read this pass. This can of course be fixed with a loop but it starts to get sorta complicated and I wonder if there is a better overall way. Second, the logic in IncomingPacket is a little bit crazy, to be able to read the two bytes for the length and then read the actual data. Here is the code, boiled down for quick & easy reading: int readBytes; // number of total bytes read so far byte length1, length2; // each byte in an unsigned short int (see getLength()) public int getLength() { // will be inaccurate if readBytes < 2 return (int)(length1 << 8 | length2); } public void readData(SocketChannel c) { if (readBytes < 2) { // we don't yet know the length of the actual data ByteBuffer lengthBuffer = ByteBuffer.allocate(2 - readBytes); numBytesRead = c.read(lengthBuffer); if(readBytes == 0) { if(numBytesRead >= 1) length1 = lengthBuffer.get(); if(numBytesRead == 2) length2 = lengthBuffer.get(); } else if(readBytes == 1) { if(numBytesRead == 1) length2 = lengthBuffer.get(); } readBytes += numBytesRead; } if(readBytes >= 2) { // then we know we have the entire length variable // lazily-instantiate data buffers based on getLength() // read into data buffers, increment readBytes // (does not read more than the amount of this packet, so it does not // need to handle overflow into the next packet's data) } } public boolean complete() { return (readBytes > 2 && readBytes == getLength()+2); } Basically I need feedback on my code. Please suggest any improvements. Even overhauling my entire system would be okay, if you have suggestions for how better to implement the whole thing. Book recommendations are welcome too; I love books. I just get the feeling that something isn't quite right.

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Including objects from external .js files

- by Molle

I have been searching for many hours over several days for this answer and though there are many topics on how to include files in a project (also here at Stack Overflow), I have not yet found THE solution to my problem. I'm working on a project where I want to include one single object at a time, from many different files (I do not want to include the files themselves, only their content). All the object in all the files have the same name, only the content is different. It is important that I do not get a SCRIPT tag in the head section of the page as all the content from the files will have the same names. None of the files will have functions anyways, only one single object, that will need to be loaded one at the time and then discarded when the next element is loaded. The objects will hold the data that will be shown on the page and they will be called from the menu by an 'onclick' event. function setMenu() // The menu is being build. { var html = ''; html += '<table border="0">'; for (var i = 0; i<menu.pages.length; i++) { html += '<tr class="menuPunkt"><td width="5"></td><td onclick="pageName(this)">'+ menu.pages[i] +'</td><td width="5"></td></tr>'; } // menu is a global object containing elements such as an array with // all the pages that needs to be shown and styling for the menu. html += '</table>'; document.getElementById("menu").innerHTML = html; style.setMenu(); // The menu is being positioned and styled. } Now, when I click on a menu item the pageName function is triggered and I'm sending the HTML element to the function as well, it is here that I want the content from my external file to be loaded into a local variable and used to display content on the page. ** The answer I want is "How to load the external obj into the function where I need it? (It may be an external file, but only in the term of not being included in the head section. I'm still loading the the file from my own local library.** function pageName(elm) // The element that I clicked is elm. { var page = info.innerHTML; // I need only the innerHTML from the element. var file = 'sites/' + page + '.js'; // The file to be loaded is created. var obj = ?? // Here I somehow want the object from the external file to be loaded. // Before doing stuff the the obj. style.content(); } The content from the external file could look like this: // The src for the external page: 'sites/page.js' var obj = new Object() { obj.innerHTML = 'Text to be shown'; obj.style = 'Not important for problem at hand'; obj.otherStuff = ' --||-- '; } Any help will be appreciated, Molle

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Opinions on Copy Protection / Software Licensing via phoning home?

- by Jakobud

I'm developing some software that I'm going to eventually sell. I've been thinking about different copy protection mechanisms, both custom and 3rd party. I know that no copy protection is 100% full-proof, but I need to at least try. So I'm looking for some opinions to my approach I'm thinking about: One method I'm thinking about is just having my software connect to a remote server when it starts up, in order to verify the license based off the MAC address of the ethernet port. I'm not sure if the server would be running a MySQL database that retrieves the license information, or what... Is there a more simple way? Maybe some type of encrypted file that is read? I would make the software still work if it can't connect to the server. I don't want to lock someone out just because they don't have internet access at that moment in time. In case you are wondering, the software I'm developing is extremely internet/network dependant. So its actually quite unlikely that the user wouldn't have internet access when using it. Actually, its pretty useless without internet/network access. Anyone know what I would do about computers that have multiple MAC addresses? A lot of motherboards these days have 2 ethernet ports. And most laptops have 1 ethernet, 1 wifi and Bluetooth MAC addresses. I suppose I could just pick a MAC port and run with it. Not sure if it really matters A smarty and tricky user could determine the server that the software is connecting to and perhaps add it to their host file so that it always trys to connect to localhost. How likely do you think this is? And do you think its possible for the software to check if this is being done? I guess parsing of the host file could always work. Look for your server address in there and see if its connecting to localhost or something. I've considered dongles, but I'm trying to avoid them just because I know they are a pain to work with. Keeping them updated and possibly requiring the customer to run their own license server is a bit too much for me. I've experienced that and it's a bit of a pain that I wouldn't want to put my customers through. Also I'm trying to avoid that extra overhead cost of using 3rd party dongles. Also, I'm leaning toward connecting to a remote server to verify authentication as opposed to just sending the user some sort of license file because what happens when the user buys a new computer? I have to send them a replacement license file that will work with their new computer, but they will still be able to use it on their old computer as well. There is no way for me to 'de-authorize' their old computer without asking them to run some program on it or something. Also, one important note, with the software I would make it very clear to the user in the EULA that the software connects to a remote server to verify licensing and that no personal information is sent. I know I don't care much for software that does that kinda stuff without me knowing. Anyways, just looking for some opinions for people who have maybe gone down this kinda road. It seems like remote-server-dependent-software would be one of the most effective copy-protection mechanisms, not just because of difficulty of circumventing, but also could be pretty easy to manage the licenses on the developers end.

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JDBC Lock a row using SELECT FOR UPDATE, doesn't work

- by Rachid

I am having issues with MySQL's SELECT .. FOR UPDATE, here is the query I am trying to run: SELECT * FROM tableName WHERE HostName='UnknownHost' ORDER BY UpdateTimestamp asc limit 1 FOR UPDATE After this, the concerned thread will do an UPDATE and change the HostName, which is then it should unlock the row. I am running a multi-threaded java application, so 3 threads are running this SQL statement, but when thread 1 runs this, it doesn't lock its results from thread 2 & 3. Therefore threads 2 & 3 are getting the same results and they could update the same row. Also each thread is on its own mysql connection. I'm using Innodb, with transaction-isolation = READ-COMMITTED, and the Autocommit is off before executing the select for update may I miss something? OR perhaps there is a better solution? Thanks a lot. Code : public BasicJDBCDemo() { Le_Thread newThread1=new Le_Thread(); Le_Thread newThread2=new Le_Thread(); newThread1.start(); newThread2.start(); } Thread : class Le_Thread extends Thread { public void run() { tring name = Thread.currentThread().getName(); System.out.println( name+": Debut."); long oid=Util.doSelectLockTest(name); Util.doUpdateTest(oid,name); } } Select : public static long doSelectLockTest(String threadName) { System.out.println("[OUTPUT FROM SELECT Lock ]...threadName="+threadName); PreparedStatement pst = null; ResultSet rs=null; Connection conn=null; long oid=0; try { String query = "SELECT * FROM table WHERE Host=? ORDER BY Timestamp asc limit 1 FOR UPDATE"; conn=getNewConnection(); pst = conn.prepareStatement(query); pst.setString(1, DbProperties.UnknownHost); System.out.println("pst="+threadName+"__"+pst); rs = pst.executeQuery(); if (rs.first()) { String s = rs.getString("HostName"); oid = rs.getLong("OID"); System.out.println("oid_oldest/host/threadName=="+oid+"/"+s+"/"+threadName); } } catch (SQLException ex) { ex.printStackTrace(); } finally { DBUtil.close(pst); DBUtil.close(rs); DBUtil.close(conn); } return oid; } Please help.... : Result : Thread-1: Debut. Thread-2: Debut. [OUTPUT FROM SELECT Lock ]...threadName=Thread-1 New connection.. [OUTPUT FROM SELECT Lock ]...threadName=Thread-2 New connection.. pst=Thread-2: SELECT * FROM b2biCheckPoint WHERE HostName='UnknownHost' ORDER BY UpdateTimestamp asc limit 1 FOR UPDATE pst=Thread-1: SELECT * FROM b2biCheckPoint WHERE HostName='UnknownHost' ORDER BY UpdateTimestamp asc limit 1 FOR UPDATE oid_oldest/host/threadName==1/UnknownHost/Thread-2 oid_oldest/host/threadName==1/UnknownHost/Thread-1 [Performing UPDATE] ... oid = 1, thread=Thread-2 New connection.. [Performing UPDATE] ... oid = 1, thread=Thread-1 pst_threadname=Thread-2: UPDATE b2bicheckpoint SET HostName='1_host_Thread-2',UpdateTimestamp=1294940161838 where OID = 1 New connection.. pst_threadname=Thread-1: UPDATE b2bicheckpoint SET HostName='1_host_Thread-1',UpdateTimestamp=1294940161853 where OID = 1

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Windows App. Thread Aborting Issue

- by Patrick

I'm working on an application that has to make specific decisions based on files that are placed into a folder being watched by a file watcher. Part of this decision making process involves renaming files before moving them off to another folder to be processed. Since I'm working with files of all different sizes I created an object that checks the file in a seperate thread to verify that it is "available" and when it is it fires an event. When I run the rename code from inside this available event it works. public void RenameFile_Test() { string psFilePath = @"C:\File1.xlsx"; tgt_File target = new FileObject(psFilePath); target.FileAvailable += new FileEventHandler(OnFileAvailable); target.FileUnAvailable += new FileEventHandler(OnFileUnavailable); } private void OnFileAvailable(object source, FileEventArgs e) { ((FileObject)source).RenameFile(@"C:\File2.xlsx"); } The problem I'm running into is that when the extensions are different from the source file and the rename to file I am making a call to a conversion factory that returns a factory object based on the type of conversion and then converts the file accordingly before doing the rename. When I run that particular piece of code in unit test it works, the factory object is returned, and the conversion happens correctly. But when I run it within the process I get up to the... moExcelApp = new Application(); part of converting an .xls or .xlsx to a .csv and i get a "Thread was being Aborted" error. Any thoughts? Update: There is a bit more information and a bit of map of how the application works currently. Client Application running FSW On File Created event Creates a FileObject passing in the path of the file. On construction the file is validated: if file exists is true then, Thread toAvailableCheck = new Thread(new ThreadStart(AvailableCheck)); toAvailableCheck.Start(); The AvailableCheck Method repeatedly tries to open a streamreader to the file until the reader is either created or the number of attempts times out. If the reader is opened, it fires the FileAvailable event, if not it fires the FileUnAvailable event, passing back itself in the event. The client application is wired to catch those events from inside the Oncreated event of the FSW. the OnFileAvailable method then calls the rename functionality which contains the excel interop call. If the file is being renamed (not converted, extensions stay the same) it does a move to change the name from the old file name to the new, and if its a conversion it runs a conversion factory object which returns the correct type of conversion based on the extensions of the source file and the destination file name. If it is a simple rename it works w/o a problem. If its a conversion (which is the XLS to CSV object that is returned as a part of the factory) the very first thing it does is create a new application object. That is where the application bombs. When i test the factory and conversion/rename process outside of the thread and in its own unit test the process works w/o a problem. Update: I tested the Excel Interop inside a thread by doing this: [TestMethod()] public void ExcelInteropTest() { Thread toExcelInteropThreadTest = new Thread(new ThreadStart(Instantiate_App)); toExcelInteropThreadTest.Start(); } private void Instantiate_App() { Application moExcelApp = new Application(); moExcelApp.Quit(); } And on the line where the application is instatntiated I got the 'A first chance exception of type 'System.Threading.ThreadAbortException' error. So I added; toExcelInteropThreadTest.SetApartmentState(ApartmentState.MTA); after the thread instantiation and before the thread start call and still got the same error. I'm getting the notion that I'm going to have to reconsider the design.

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Tool or library for end-users to run queries to select (not modify) data?

- by Mark Rushakoff

For a utility I'm working on, the client would like to be able to generate graphic reports on the data that has been collected. I can already generate a couple canned graphs (using ZedGraph, which is a very nice library); however, the utility would be much more flexible if the graphs were more programmable or configurable by the end-user. TLDR version I want users to be able to use something like SQL to safely extract and select data from a List of objects that I provide and can describe. What free tools or libraries will help me accomplish this? Full version I've given thought to using IronPython, IronRuby, and LuaInterface, but frankly they're all a bit overpowered for what I want to do. My classes are fairly simple, along the lines of: class Person: string Name; int HeightInCm; DateTime BirthDate; Weight[] WeighIns; class Weight: int WeightInKg; DateTime Date; Person Owner; (exact classes have been changed to protect the innocent). To come up with the data for the graph, the user will choose whether it's a bar graph, scatter plot, etc., and then to actually obtain the data, I would like to obtain some kind of List from the user simply entering something SQL-ish along the lines of SELECT Name, AVG(WeighIns) FROM People SELECT WeightInKg, Owner.HeightInCm FROM Weights And as a bonus, it would be nice if you could actually do operations as well: SELECT WeightInKg, (Date - Owner.BirthDate) AS Age FROM Weights The DSL doesn't have to be compliant SQL in any way; it doesn't even have to resemble SQL, but I can't think of a more efficient descriptive language for the task. I'm fine filling in blanks; I don't expect a library to do everything for me. What I would expect to exist (but haven't been able to find in any way, shape, or form) is something like Fluent NHibernate (which I am already using in the project) where I can declare a mapping, something like var personRequest = Request<Person>(); personRequest.Item("Name", (p => p.Name)); personRequest.Item("HeightInCm", (p => p.HeightInCm)); personRequest.Item("HeightInInches", (p => p.HeightInCm * CM_TO_INCHES)); // ... var weightRequest = Request<Weight>(); weightRequest.Item("Owner", (w => w.Owner), personRequest); // Indicate a chain to personRequest // ... var people = Table<Person>("People", GetPeopleFromDatabase()); var weights = Table<Weight>("Weights", GetWeightsFromDatabase()); // ... TryRunQuery(userInputQuery); LINQ is so close to what I want to do, but AFAIK there's no way to sandbox it. I don't want to expose any unnecessary functionality to the end user; meaning I don't want the user to be able to send in and process: from p in people select (p => { System.IO.File.Delete("C:\\something\\important"); return p.Name }) So does anyone know of any free .NET libraries that allow something like what I've described above? Or is there some way to sandbox LINQ? cs-script is close too, but it doesn't seem to offer sandboxing yet either. I'd be hesitant to expose the NHibernate interface either, as the user should have a read-only view of the data at this point in the usage. I'm using C# 3.5, and pure .NET solutions would be preferred. The bottom line is that I'm really trying to avoid writing my own parser for a subset of SQL that would only apply to this single project.

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How to select table column names in a view and pass to controller in rails?

- by zachd1_618

So I am new to Rails, and OO programming in general. I have some grasp of the MVC architecture. My goal is to make a (nearly) completely dynamic plug-and-play plotting web server. I am fairly confused with params, forms, and select helpers. What I want to do is use Rails drop downs to basically pass parameters as strings to my controller, which will use the params to select certain column data from my database and plot it dynamically. I have the latter part of the task working, but I can't seem to pass values from my view to controller. For simplicity's sake, say my database schema looks like this: --------------Plot--------------- |____x____|____y1____|____y2____| | 1 | 1 | 1 | | 2 | 2 | 4 | | 3 | 3 | 9 | | 4 | 4 | 16 | | 5 | 5 | 25 | ... and in my Model, I have dynamic selector scopes that will let me select just certain columns of data: in Plot.rb class Plot < ActiveRecord::Base scope :select_var, lambda {|varname| select(varname)} scope :between_x, lambda {|x1,x2| where("x BETWEEN ? and ?","#{x1}","#{x2}")} So this way, I can call: irb>>@p1 = Plot.select_var(['x','y1']).between_x(1,3) and get in return a class where @p1.x and @p1.y1 are my only attributes, only for values between x=1 to x=4, which I dynamically plot. I want to start off in a view (plot/index), where I can dynamically select which variable names (table column names), and which rows from the database to fetch and plot. The problem is, most select helpers don't seem to work with columns in the database, only rows. So to select columns, I first get an array of column names that exist in my database with a function I wrote. Plots Controller def index d=Plot.first @tags = d.list_vars end So @tags = ['x','y1','y2'] Then in my plot/index.html.erb I try to use a drop down to select wich variables I send back to the controller. index.html.erb <%= select_tag( :variable, options_for_select(@plots.first.list_vars,:name,:multiple=>:true) )%> <%= button_to 'Plot now!', :controller =>"plots/plot_vars", :variable => params[:variable]%> Finally, in the controller again Plots controller ... def plot_vars @plot_data=Plot.select_vars([params[:variable]]) end The problem is everytime I try this (or one of a hundred variations thereof), the params[:variable] is nill. How can I use a drop down to pass a parameter with string variable names to the controller? Sorry its so long, I have been struggling with this for about a month now. :-( I think my biggest problem is that this setup doesn't really match the Rails architecture. I don't have "users" and "articles" as individual entities. I really have a data structure, not a data object. Trying to work with the structure in terms of data object speak is not necessarily the easiest thing to do I think. For background: My actual database has about 250 columns and a couple million rows, and they get changed and modified from time to time. I know I can make the database smarter, but its not worth it on my end. I work at a scientific institute where there are a ton of projects with databases just like this. Each one has a web developer that spends months setting up a web interface and their own janky plotting setups. I want to make this completely dynamic, as a plug-and-play solution so all you have to do is specify your database connection, and this rails setup will automatically show and plot which data you want in it. I am more of a sequential programmer and number cruncher, as are many people here. I think this project could be very helpful in the end, but its difficult to figure out for me right now.

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Calculate the number of ways to roll a certain number

- by helloworld

I'm a high school Computer Science student, and today I was given a problem to: Program Description: There is a belief among dice players that in throwing three dice a ten is easier to get than a nine. Can you write a program that proves or disproves this belief? Have the computer compute all the possible ways three dice can be thrown: 1 + 1 + 1, 1 + 1 + 2, 1 + 1 + 3, etc. Add up each of these possibilities and see how many give nine as the result and how many give ten. If more give ten, then the belief is proven. I quickly worked out a brute force solution, as such int sum,tens,nines; tens=nines=0; for(int i=1;i<=6;i++){ for(int j=1;j<=6;j++){ for(int k=1;k<=6;k++){ sum=i+j+k; //Ternary operators are fun! tens+=((sum==10)?1:0); nines+=((sum==9)?1:0); } } } System.out.println("There are "+tens+" ways to roll a 10"); System.out.println("There are "+nines+" ways to roll a 9"); Which works just fine, and a brute force solution is what the teacher wanted us to do. However, it doesn't scale, and I am trying to find a way to make an algorithm that can calculate the number of ways to roll n dice to get a specific number. Therefore, I started generating the number of ways to get each sum with n dice. With 1 die, there is obviously 1 solution for each. I then calculated, through brute force, the combinations with 2 and 3 dice. These are for two: There are 1 ways to roll a 2 There are 2 ways to roll a 3 There are 3 ways to roll a 4 There are 4 ways to roll a 5 There are 5 ways to roll a 6 There are 6 ways to roll a 7 There are 5 ways to roll a 8 There are 4 ways to roll a 9 There are 3 ways to roll a 10 There are 2 ways to roll a 11 There are 1 ways to roll a 12 Which looks straightforward enough; it can be calculated with a simple linear absolute value function. But then things start getting trickier. With 3: There are 1 ways to roll a 3 There are 3 ways to roll a 4 There are 6 ways to roll a 5 There are 10 ways to roll a 6 There are 15 ways to roll a 7 There are 21 ways to roll a 8 There are 25 ways to roll a 9 There are 27 ways to roll a 10 There are 27 ways to roll a 11 There are 25 ways to roll a 12 There are 21 ways to roll a 13 There are 15 ways to roll a 14 There are 10 ways to roll a 15 There are 6 ways to roll a 16 There are 3 ways to roll a 17 There are 1 ways to roll a 18 So I look at that, and I think: Cool, Triangular numbers! However, then I notice those pesky 25s and 27s. So it's obviously not triangular numbers, but still some polynomial expansion, since it's symmetric. So I take to Google, and I come across this page that goes into some detail about how to do this with math. It is fairly easy(albeit long) to find this using repeated derivatives or expansion, but it would be much harder to program that for me. I didn't quite understand the second and third answers, since I have never encountered that notation or those concepts in my math studies before. Could someone please explain how I could write a program to do this, or explain the solutions given on that page, for my own understanding of combinatorics? EDIT: I'm looking for a mathematical way to solve this, that gives an exact theoretical number, not by simulating dice

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Table Name is null in the sqlite database in android device

- by Mahe

I am building a simple app which stores some contacts and retrieves contacts in android phone device. I have created my own database and a table and inserting the values to the table in phone. My phone is not rooted. So I cannot access the files, but I see that values are stored in the table. And tested on a emulator also. Till here it is fine. Display all the contacts in a list by fetching data from table. This is also fine. But the problem is When I am trying to delete the record, it shows the table name is null in the logcat(not an exception), and the data is not deleted. But in emulator the data is getting deleted from table. I am not able to achieve this through phone. This is my code for deleting, public boolean onContextItemSelected(MenuItem item) { super.onContextItemSelected(item); AdapterView.AdapterContextMenuInfo info = (AdapterView.AdapterContextMenuInfo) item .getMenuInfo(); int menuItemIndex = item.getItemId(); String[] menuItems = getResources().getStringArray(R.array.menu); String menuItemName = menuItems[menuItemIndex]; String listItemName = Customers[info.position]; if (item.getTitle().toString().equalsIgnoreCase("Delete")) { Toast.makeText( context, "Selected List item is: " + listItemName + "MenuItem is: " + menuItemName, Toast.LENGTH_LONG).show(); DB = context.openOrCreateDatabase("CustomerDetails.db", MODE_PRIVATE, null); try { int pos = info.position; pos = pos + 1; Log.d("", "customers[pos]: " + Customers[info.position]); Cursor c = DB .rawQuery( "Select customer_id,first_name,last_name from CustomerInfo", null); int rowCount = c.getCount(); DB.delete(Table_name, "customer_id" + "=" + String.valueOf(pos), null); DB.close(); Log.d("", "" + String.valueOf(pos)); Toast.makeText(context, "Deleted Customer", Toast.LENGTH_LONG) .show(); // Customers[info.position]=null; getCustomers(); } catch (Exception e) { Toast.makeText(context, "Delete unsuccessfull", Toast.LENGTH_LONG).show(); } } this is my logcat, 07-02 10:12:42.976: D/Cursor(1560): Database path: CustomerDetails.db 07-02 10:12:42.976: D/Cursor(1560): Table name : null 07-02 10:12:42.984: D/Cursor(1560): Database path: CustomerDetails.db 07-02 10:12:42.984: D/Cursor(1560): Table name : null Don't know the reason why data is not being deleted. Data exists in the table. This is the specification I have given for creating the table public static String customer_id="customer_id"; public static String site_id="site_id"; public static String last_name="last_name"; public static String first_name="first_name"; public static String phone_number="phone_number"; public static String address="address"; public static String city="city"; public static String state="state"; public static String zip="zip"; public static String email_address="email_address"; public static String custlat="custlat"; public static String custlng="custlng"; public static String Table_name="CustomerInfo"; final SQLiteDatabase DB = context.openOrCreateDatabase( "CustomerDetails.db", MODE_PRIVATE, null); final String CREATE_TABLE = "create table if not exists " + Table_name + " (" + customer_id + " integer primary key autoincrement, " + first_name + " text not null, " + last_name + " text not null, " + phone_number+ " integer not null, " + address+ " text not null, " + city+ " text not null, " + state+ " text not null, " + zip+ " integer not null, " + email_address+ " text not null, " + custlat+ " double, " + custlng+ " double " +" );"; DB.execSQL(CREATE_TABLE); DB.close(); Please correct my code. I am struggling from two days. Any help is appreciated!!

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javascript won't execute nested for loop

- by mcdwight6

thanks in advance for all your help! i'm fairly new to javascript, but i have a fairly strong background in java, so i thought i would try it out on this project i'm working on. essentially, what i'm trying to do is read data from an xml file and create the html code for the page i'm making. i used the script from w3schools found here. I've altered it and gotten it to pull the data from my own xml and even to do the more basic generation of the html code i need. Here's the html i'm using inside <script> tags: var s = swDoc.getElementsByTagName("planet"); var plShowsArr = s[i].getElementsByTagName("show"); var plGamesArr = s[i].getElementsByTagName("videoGame"); for (i=0;i<s.length;i++) { // test section all works document.write("<div><table border = \"1\">"); document.write("<tr><td>"+ s[i].getElementsByTagName("showText")[0].childNodes[0].nodeValue + "</td><td>" + s[i].getElementsByTagName("showUrl")[0].childNodes[0].nodeValue + "</td></tr>"); document.write("<tr><td>" + s[i].getElementsByTagName("gameText")[0].childNodes[0].nodeValue + "</td><td>" + s[i].getElementsByTagName("gameUrl")[0].childNodes[0].nodeValue + "</td></tr>"); document.write("</tr></table></div>"); // end test section document.write("<div class=\"appearances-row\"><ol class=\"shows\">shows list"); for(j=0;j<plShows.length;j++){ document.write("nested for"); var showUrl = s[i].getElementsByTagName("showUrl")[j].childNodes[0].nodeValue; var showText = s[i].getElementByTagName("showText")[j].childNodes[0].nodeValue; document.write("<li><a href=\""+showUrl+"\">"+showText+"</a></li>"); } the code breaks at the nested for loop at the end, where it finished the document.write and prints "shows list" to the page, but then never gets to the document.write inside. if it helps, the xml contains a list of planets from the star wars universe organized like this: <planets> <planet> <planetName>planet</planetName> <description>some text</description> <appearances> <show> <showUrl>url</showUrl> <showText>hyperlink text</showText> </show> <videoGame> <gameUrl>url</gameUrl> <gameText>hyperlink text</gameText> </videoGame> </appearances> <locationsOfInterest> <location>location name</location> </locationsOfInterest> <famousCharactersRelatedTo> <character>a character</character> </famousCharactersRelatedTo> <externalLinks> <link> <linkUrl>url</linkUrl> <linkText>hyperlink text</linkText> </link> </externalLinks> </planet>

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Which of CouchDB or MongoDB suits my needs?

- by vonconrad

Where I work, we use Ruby on Rails to create both backend and frontend applications. Usually, these applications interact with the same MySQL database. It works great for a majority of our data, but we have one situation which I would like to move to a NoSQL environment. We have clients, and our clients have what we call "inventories"--one or more of them. An inventory can have many thousands of items. This is currently done through two relational database tables, inventories and inventory_items. The problems start when two different inventories have different parameters: # Inventory item from inventory 1, televisions { inventory_id: 1 sku: 12345 name: Samsung LCD 40 inches model: 582903-4 brand: Samsung screen_size: 40 type: LCD price: 999.95 } # Inventory item from inventory 2, accomodation { inventory_id: 2 sku: 48cab23fa name: New York Hilton accomodation_type: hotel star_rating: 5 price_per_night: 395 } Since we obviously can't use brand or star_rating as the column name in inventory_items, our solution so far has been to use generic column names such as text_a, text_b, float_a, int_a, etc, and introduce a third table, inventory_schemas. The tables now look like this: # Inventory schema for inventory 1, televisions { inventory_id: 1 int_a: sku text_a: name text_b: model text_c: brand int_b: screen_size text_d: type float_a: price } # Inventory item from inventory 1, televisions { inventory_id: 1 int_a: 12345 text_a: Samsung LCD 40 inches text_b: 582903-4 text_c: Samsung int_a: 40 text_d: LCD float_a: 999.95 } This has worked well... up to a point. It's clunky, it's unintuitive and it lacks scalability. We have to devote resources to set up inventory schemas. Using separate tables is not an option. Enter NoSQL. With it, we could let each and every item have their own parameters and still store them together. From the research I've done, it certainly seems like a great alterative for this situation. Specifically, I've looked at CouchDB and MongoDB. Both look great. However, there are a few other bits and pieces we need to be able to do with our inventory: We need to be able to select items from only one (or several) inventories. We need to be able to filter items based on its parameters (eg. get all items from inventory 2 where type is 'hotel'). We need to be able to group items based on parameters (eg. get the lowest price from items in inventory 1 where brand is 'Samsung'). We need to (potentially) be able to retrieve thousands of items at a time. We need to be able to access the data from multiple applications; both backend (to process data) and frontend (to display data). Rapid bulk insertion is desired, though not required. Based on the structure, and the requirements, are either CouchDB or MongoDB suitable for us? If so, which one will be the best fit? Thanks for reading, and thanks in advance for answers. EDIT: One of the reasons I like CouchDB is that it would be possible for us in the frontend application to request data via JavaScript directly from the server after page load, and display the results without having to use any backend code whatsoever. This would lead to better page load and less server strain, as the fetching/processing of the data would be done client-side.

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HMTL5 Anti Aliasing Browser Disable

- by Tappa Tappa

I am forced to consider writing a library to handle the fundamental basics of drawing lines, thick lines, circles, squares etc. of an HTML5 canvas because I can't disable a feature embedded in the browser rendering of the core canvas algorithms. Am I forced to build the HTML5 Canvas rendering process from the ground up? If I am, who's in with me to do this? Who wants to change the world? Imagine a simple drawing application written in HTML5... you draw a shape... a closed shape like a rudimentary circle, free hand, more like an onion than a circle (well, that's what mine would look like!)... then imagine selecting a paint bucket icon and clicking inside that shape you drew and expecting it to be filled with a color of your choice. Imagine your surprise as you selected "Paint Bucket" and clicked in the middle of your shape and it filled your shape with color... BUT, not quite... HANG ON... this isn't right!!! On the inside of the edge of the shape you drew is a blur between the background color and your fill color and the edge color... the fill seems to be flawed. You wanted a straight forward "Paint Bucket" / "Fill"... you wanted to draw a shape and then fill it with a color... no fuss.... fill the whole damned inside of your shape with the color you choose. Your web browser has decided that when you draw the lines to define your shape they will be anti-aliased. If you draw a black line for your shape... well, the browser will draw grey pixels along the edges, in places... to make it look like a "better" line. Yeah, a "better" line that **s up the paint / flood fill process. How much does is cost to pay off the browser developers to expose a property to disable their anti-aliasing rendering? Disabling would save milliseconds for their rendering engine, surely! Bah, I really don't want to have to build my own canvas rendering engine using Bresenham line rendering algorithm... WHAT CAN BE DONE... HOW CAN THIS BE CHANGED!!!??? Do I need to start a petition aimed at the WC3???? Will you include your name if you are interested??? UPDATED function DrawLine(objContext, FromX, FromY, ToX, ToY) { var dx = Math.abs(ToX - FromX); var dy = Math.abs(ToY - FromY); var sx = (FromX < ToX) ? 1 : -1; var sy = (FromY < ToY) ? 1 : -1; var err = dx - dy; var CurX, CurY; CurX = FromX; CurY = FromY; while (true) { objContext.fillRect(CurX, CurY, objContext.lineWidth, objContext.lineWidth); if ((CurX == ToX) && (CurY == ToY)) break; var e2 = 2 * err; if (e2 > -dy) { err -= dy; CurX += sx; } if (e2 < dx) { err += dx; CurY += sy; } } }

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load search results into a div that toggles with other divs

- by Z. Edwards

I am working with a page that has multiple divs that toggle. This function works. A search function was added and this works too. The problem with the page as it exists currently: The search bar was placed on the "default" div and the results load below the bar into another div that is invisible when empty. The results div is inside this first default div. If you toggle to another div, you lose the default div and can't get back to it. For this reason, I moved the search bar to the left navigation where the other toggle links are situated. I also moved the search results div out of the default div to "stand on its own." What I am trying to do: Make the search button show the div with the results as well as find the results. Basically, to integrate the search function into the array/toggle function. The search function is in one .js file and the toggle function is in a different .js file. I keep thinking there must be a way to get "onclick" to call from both .js files so that I don't have to do a bunch of extra work combining the two functions that already exist and work separately. I am a Javascript newbie learning by examples and haven't been able to figure this out. I have never seen a working example of this and my searches haven't produced one. I would be very grateful for any help. Hope I explained the problem adequately. Edit: Here is the code I already have for the toggle function. var ids=new Array('a','b','c',[and so on--search results not added here yet]); function switchid(id_array){ hideallids(); for( var i=0, limit=id_array.length; i < limit; ++i) showdiv(id_array[i]); } function hideallids(){ for (var i=0;i<ids.length;i++){ hidediv(ids[i]); } } function hidediv(id) { //safe function to hide an element with a specified id if (document.getElementById) { // DOM3 = IE5, NS6 document.getElementById(id).style.display = 'none'; } else { if (document.layers) { // Netscape 4 document.id.display = 'none'; } else { // IE 4 document.all.id.style.display = 'none'; } } } function showdiv(id) {//safe function to show an element with a specified id if (document.getElementById) { // DOM3 = IE5, NS6 document.getElementById(id).style.display = 'block'; } else { if (document.layers) { // Netscape 4 document.id.display = 'block'; } else { // IE 4 document.all.id.style.display = 'block'; } } } function initialize(){ var t = gup("target"); if( t ) { switchid([t]); } } function gup( name ) { name = name.replace(/[\[]/,"\\\[").replace(/[\]]/,"\\\]"); var regexS = "[\\?&]"+name+"=([^&#]*)"; var regex = new RegExp( regexS ); var results = regex.exec( window.location.href ); if( results == null ){ return ""; } else { return results[1]; } } Thanks in advance!

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Alphabetically Ordering an array of words

- by Genesis

I'm studying C on my own in preparation for my upcoming semester of school and was wondering what I was doing wrong with my code so far. If Things look weird it is because this is part of a much bigger grab bag of sorting functions I'm creating to get a sense of how to sort numbers,letters,arrays,and the like! I'm basically having some troubles with the manipulation of strings in C currently. Also, I'm quite limited in my knowledge of C at the moment! My main Consists of this: #include <stdio.h> #include <stdio.h> #include <stdlib.h> int numbers[10]; int size; int main(void){ setvbuf(stdout,NULL,_IONBF,0); //This is magical code that allows me to input. int wordNumber; int lengthOfWord = 50; printf("How many words do you want to enter: "); scanf("%i", &wordNumber); printf("%i\n",wordNumber); char words[wordNumber][lengthOfWord]; printf("Enter %i words:",wordNumber); int i; for(i=0;i<wordNumber+1;i++){ //+1 is because my words[0] is blank. fgets(&words[i], 50, stdin); } for(i=1;i<wordNumber+1;i++){ // Same as the above comment! printf("%s", words[i]); //prints my words out! } alphabetize(words,wordNumber); //I want to sort these arrays with this function. } My sorting "method" I am trying to construct is below! This function is seriously flawed, but I'd thought I'd keep it all to show you where my mind was headed when writing this. void alphabetize(char a[][],int size){ // This wont fly. size = size+1; int wordNumber; int lengthOfWord; char sortedWords[wordNumber][lengthOfWord]; //In effort for the for loop int i; int j; for(i=1;i<size;i++){ //My effort to copy over this array for manipulation for(j=1;j<size;j++){ sortedWords[i][j] = a[i][j]; } } //This should be kinda what I want when ordering words alphabetically, right? for(i=1;i<size;i++){ for(j=2;j<size;j++){ if(strcmp(sortedWords[i],sortedWords[j]) > 0){ char* temp = sortedWords[i]; sortedWords[i] = sortedWords[j]; sortedWords[j] = temp; } } } for(i=1;i<size;i++){ printf("%s, ",sortedWords[i]); } } I guess I also have another question as well... When I use fgets() it's doing this thing where I get a null word for the first spot of the array. I have had other issues recently trying to scanf() char[] in certain ways specifically spacing my input word variables which "magically" gets rid of the first null space before the character. An example of this is using scanf() to write "Hello" and getting " Hello" or " ""Hello"... Appreciate any thoughts on this, I've got all summer to study up so this doesn't need to be answered with haste! Also, thank you stack overflow as a whole for being so helpful in the past. This may be my first post, but I have been a frequent visitor for the past couple of years and it's been one of the best places for helpful advice/tips.

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How can I make three partials into just one in rails where the :collection is the same?

- by Angela

I have three partials that I'd like to consolidate into one. They share the same collection, but each gets passed its own :local variable. Those variables are used for specific Models, so as a result, I have three different calls to the partial and three different partials. Here's the repetitive code: <% for email in campaign.emails %> <h4><%= link_to email.title, email %> <%= email.days %> days</h4> <% @contacts= campaign.contacts.find(:all, :order => "date_entered ASC" )%>   <%= render :partial => "contact_email", :collection => @contacts, :locals => {:email => email} %> <% end %> Calls in this Campaign: <% for call in campaign.calls %> <h4><%= link_to call.title, call %> <%= call.days %> days</h4> <% @contacts= campaign.contacts.find(:all, :order => "date_entered ASC" )%>   <%= render :partial => "contact_call", :collection => @contacts, :locals => {:call => call} %> <% end %> Letters in this Campaign: <% for letter in campaign.letters %> <h4><%= link_to letter.title, letter %> <%= letter.days %> days</h4> <% @contacts= campaign.contacts.find(:all, :order => "date_entered ASC" )%>   <%= render :partial => "contact_letter", :collection => @contacts, :locals => {:letter => letter} %> <% end %> An example of one of the partials is as follows: < div id="contact_email_partial"> <% if from_today(contact_email, email.days) < 0 %> <% if show_status(contact_email, email) == 'no status'%> <p> <%= full_name(contact_email) %> <% unless contact_email.statuses.empty?%> (<%= contact_email.statuses.find(:last).status%>) <% end %> is <%= from_today(contact_email,email.days).abs%> days overdue: <%= do_event(contact_email, email) %> <%= link_to_remote "Skip Email Remote", :url => skip_contact_email_url(contact_email,email), :update => "update-area-#{contact_email.id}-#{email.id}" %> <span id='update-area-<%="#{contact_email.id}-#{email.id}"%>'> </span> <% end %> <% end %> </div>

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if statement to check available elements

- by nicmare

Hi there, i allways found an answer here just be reading the threads but now its time for my very first thread because i was unable to find related questions: this is my target code: <li> <span class="panel"> <a href="…" class="image" rel="group"> <img title="…" src="…" alt="…" width="128" height="96" /> </a> <span class="sizes"> <span class="button"> <a href="#" class="size1" rel="…" title="1">9x13</a> </span> <span class="button"> <a href="#" class="size2" rel="…" title="3">10x15</a> </span> <span class="button"> <a href="#" class="size3" rel="…" title="6">20x30</a> </span> </span> </span> <a href="…" class="image" rel="group"> <span class="added"></span> <img title="…" src="…" alt="…" width="128" height="96" class="thumbnail" /> </a> </li> i add two "span" elements through jquery: $('.sizes a').click( function (e) { e.preventDefault(); $(this).after("<span class='checked'></span><span class='remove'></span>"); } ); the maximum amount of those s are 3 times in a wrapped div. so i am trying to do is the following: $(".remove").live('click', function(){ $(this).hide(); $(this).prev().hide(); // hide checked span if ($(this).parent().parent().children().children().each().hasClass('checked')) { $(this).parent().parent().parent().next().children(".added").hide(); } } ); of course my if statement is crap. i try it in my own words: if there are more than one span(class=remove) in span(class=panel) then nothing should happen. but if there is just one span(class=remove) left in span(class=panel) THEN should be hidden how do i achieve this? there is an online demonstration of this: http://bit.ly/972be4 as you can see, every time when i hit a button below an image, the image gets marked by a label. and i want to hide this label (class=added) when no button is selected Thank you very much! best wishes from germany

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What is a good java data structure for storing nested items (like cities in states)?

- by anotherAlan

I'm just getting started in Java and am looking for advice on a good way to store nested sets of data. For example, I'm interested in storing city population data that can be accessed by looking up the city in a given state. (Note: eventually, other data will be stored with each city as well, this is just the first attempt at getting started.) The current approach I'm using is to have a StateList Object which contains a HashMap that stores State Objects via a string key (i.e. HashMap<String, State>). Each State Object contains its own HashMap of City Objects keyed off the city name (i.e. HashMap<String, City>). A cut down version of what I've come up with looks like this: // TestPopulation.java public class TestPopulation { public static void main(String [] args) { // build the stateList Object StateList sl = new StateList(); // get a test state State stateAl = sl.getState("AL"); // make sure it's there. if(stateAl != null) { // add a city stateAl.addCity("Abbeville"); // now grab the city City cityAbbevilleAl = stateAl.getCity("Abbeville"); cityAbbevilleAl.setPopulation(2987); System.out.print("The city has a pop of: "); System.out.println(Integer.toString(cityAbbevilleAl.getPopulation())); } // otherwise, print an error else { System.out.println("That was an invalid state"); } } } // StateList.java import java.util.*; public class StateList { // define hash map to hold the states private HashMap<String, State> theStates = new HashMap<String, State>(); // setup constructor that loads the states public StateList() { String[] stateCodes = {"AL","AK","AZ","AR","CA","CO"}; // etc... for (String s : stateCodes) { State newState = new State(s); theStates.put(s, newState); } } // define method for getting a state public State getState(String stateCode) { if(theStates.containsKey(stateCode)) { return theStates.get(stateCode); } else { return null; } } } // State.java import java.util.*; public class State { // Setup the state code String stateCode; // HashMap for cities HashMap<String, City> cities = new HashMap<String, City>(); // define the constructor public State(String newStateCode) { System.out.println("Creating State: " + newStateCode); stateCode = newStateCode; } // define the method for adding a city public void addCity(String newCityName) { City newCityObj = new City(newCityName); cities.put(newCityName, newCityObj); } // define the method for getting a city public City getCity(String cityName) { if(cities.containsKey(cityName)) { return cities.get(cityName); } else { return null; } } } // City.java public class City { // Define the instance vars String cityName; int cityPop; // setup the constructor public City(String newCityName) { cityName = newCityName; System.out.println("Created City: " + newCityName); } public void setPopulation(int newPop) { cityPop = newPop; } public int getPopulation() { return cityPop; } } This is working for me, but I'm wondering if there are gotchas that I haven't run into, or if there are alternate/better ways to do the same thing. (P.S. I know that I need to add some more error checking in, but right now, I'm focused on trying to figure out a good data structure.) (NOTE: Edited to change setPop() and getPop() to setPopulation() and getPopulation() respectively to avoid confucsion)

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.NET HTML Sanitation for rich HTML Input

- by Rick Strahl

Recently I was working on updating a legacy application to MVC 4 that included free form text input. When I set up the new site my initial approach was to not allow any rich HTML input, only simple text formatting that would respect a few simple HTML commands for bold, lists etc. and automatically handles line break processing for new lines and paragraphs. This is typical for what I do with most multi-line text input in my apps and it works very well with very little development effort involved. Then the client sprung another note: Oh by the way we have a bunch of customers (real estate agents) who need to post complete HTML documents. Oh uh! There goes the simple theory. After some discussion and pleading on my part (<snicker>) to try and avoid this type of raw HTML input because of potential XSS issues, the client decided to go ahead and allow raw HTML input anyway. There has been lots of discussions on this subject on StackOverFlow (and here and here) but to after reading through some of the solutions I didn't really find anything that would work even closely for what I needed. Specifically we need to be able to allow just about any HTML markup, with the exception of script code. Remote CSS and Images need to be loaded, links need to work and so. While the 'legit' HTML posted by these agents is basic in nature it does span most of the full gamut of HTML (4). Most of the solutions XSS prevention/sanitizer solutions I found were way to aggressive and rendered the posted output unusable mostly because they tend to strip any externally loaded content. In short I needed a custom solution. I thought the best solution to this would be to use an HTML parser - in this case the Html Agility Pack - and then to run through all the HTML markup provided and remove any of the blacklisted tags and a number of attributes that are prone to JavaScript injection. There's much discussion on whether to use blacklists vs. whitelists in the discussions mentioned above, but I found that whitelists can make sense in simple scenarios where you might allow manual HTML input, but when you need to allow a larger array of HTML functionality a blacklist is probably easier to manage as the vast majority of elements and attributes could be allowed. Also white listing gets a bit more complex with HTML5 and the new proliferation of new HTML tags and most new tags generally don't affect XSS issues directly. Pure whitelisting based on elements and attributes also doesn't capture many edge cases (see some of the XSS cheat sheets listed below) so even with a white list, custom logic is still required to handle many of those edge cases. The Microsoft Web Protection Library (AntiXSS) My first thought was to check out the Microsoft AntiXSS library. Microsoft has an HTML Encoding and Sanitation library in the Microsoft Web Protection Library (formerly AntiXSS Library) on CodePlex, which provides stricter functions for whitelist encoding and sanitation. Initially I thought the Sanitation class and its static members would do the trick for me,but I found that this library is way too restrictive for my needs. Specifically the Sanitation class strips out images and links which rendered the full HTML from our real estate clients completely useless. I didn't spend much time with it, but apparently I'm not alone if feeling this library is not really useful without some way to configure operation. To give you an example of what didn't work for me with the library here's a small and simple HTML fragment that includes script, img and anchor tags. I would expect the script to be stripped and everything else to be left intact. Here's the original HTML:var value = "<b>Here</b> <script>alert('hello')</script> we go. Visit the " + "<a href='http://west-wind.com'>West Wind</a> site. " + "<img src='http://west-wind.com/images/new.gif' /> " ; and the code to sanitize it with the AntiXSS Sanitize class:@Html.Raw(Microsoft.Security.Application.Sanitizer.GetSafeHtmlFragment(value)) This produced a not so useful sanitized string: Here we go. Visit the <a>West Wind</a> site. While it removed the <script> tag (good) it also removed the href from the link and the image tag altogether (bad). In some situations this might be useful, but for most tasks I doubt this is the desired behavior. While links can contain javascript: references and images can 'broadcast' information to a server, without configuration to tell the library what to restrict this becomes useless to me. I couldn't find any way to customize the white list, nor is there code available in this 'open source' library on CodePlex. Using Html Agility Pack for HTML Parsing The WPL library wasn't going to cut it. After doing a bit of research I decided the best approach for a custom solution would be to use an HTML parser and inspect the HTML fragment/document I'm trying to import. I've used the HTML Agility Pack before for a number of apps where I needed an HTML parser without requiring an instance of a full browser like the Internet Explorer Application object which is inadequate in Web apps. In case you haven't checked out the Html Agility Pack before, it's a powerful HTML parser library that you can use from your .NET code. It provides a simple, parsable HTML DOM model to full HTML documents or HTML fragments that let you walk through each of the elements in your document. If you've used the HTML or XML DOM in a browser before you'll feel right at home with the Agility Pack. Blacklist based HTML Parsing to strip XSS Code For my purposes of HTML sanitation, the process involved is to walk the HTML document one element at a time and then check each element and attribute against a blacklist. There's quite a bit of argument of what's better: A whitelist of allowed items or a blacklist of denied items. While whitelists tend to be more secure, they also require a lot more configuration. In the case of HTML5 a whitelist could be very extensive. For what I need, I only want to ensure that no JavaScript is executed, so a blacklist includes the obvious <script> tag plus any tag that allows loading of external content including <iframe>, <object>, <embed> and <link> etc. <form> is also excluded to avoid posting content to a different location. I also disallow <head> and <meta> tags in particular for my case, since I'm only allowing posting of HTML fragments. There is also some internal logic to exclude some attributes or attributes that include references to JavaScript or CSS expressions. The default tag blacklist reflects my use case, but is customizable and can be added to. Here's my HtmlSanitizer implementation:using System.Collections.Generic; using System.IO; using System.Xml; using HtmlAgilityPack; namespace Westwind.Web.Utilities { public class HtmlSanitizer { public HashSet<string> BlackList = new HashSet<string>() { { "script" }, { "iframe" }, { "form" }, { "object" }, { "embed" }, { "link" }, { "head" }, { "meta" } }; /// <summary> /// Cleans up an HTML string and removes HTML tags in blacklist /// </summary> /// <param name="html"></param> /// <returns></returns> public static string SanitizeHtml(string html, params string[] blackList) { var sanitizer = new HtmlSanitizer(); if (blackList != null && blackList.Length > 0) { sanitizer.BlackList.Clear(); foreach (string item in blackList) sanitizer.BlackList.Add(item); } return sanitizer.Sanitize(html); } /// <summary> /// Cleans up an HTML string by removing elements /// on the blacklist and all elements that start /// with onXXX . /// </summary> /// <param name="html"></param> /// <returns></returns> public string Sanitize(string html) { var doc = new HtmlDocument(); doc.LoadHtml(html); SanitizeHtmlNode(doc.DocumentNode); //return doc.DocumentNode.WriteTo(); string output = null; // Use an XmlTextWriter to create self-closing tags using (StringWriter sw = new StringWriter()) { XmlWriter writer = new XmlTextWriter(sw); doc.DocumentNode.WriteTo(writer); output = sw.ToString(); // strip off XML doc header if (!string.IsNullOrEmpty(output)) { int at = output.IndexOf("?>"); output = output.Substring(at + 2); } writer.Close(); } doc = null; return output; } private void SanitizeHtmlNode(HtmlNode node) { if (node.NodeType == HtmlNodeType.Element) { // check for blacklist items and remove if (BlackList.Contains(node.Name)) { node.Remove(); return; } // remove CSS Expressions and embedded script links if (node.Name == "style") { if (string.IsNullOrEmpty(node.InnerText)) { if (node.InnerHtml.Contains("expression") || node.InnerHtml.Contains("javascript:")) node.ParentNode.RemoveChild(node); } } // remove script attributes if (node.HasAttributes) { for (int i = node.Attributes.Count - 1; i >= 0; i--) { HtmlAttribute currentAttribute = node.Attributes[i]; var attr = currentAttribute.Name.ToLower(); var val = currentAttribute.Value.ToLower(); span style="background: white; color: green">// remove event handlers if (attr.StartsWith("on")) node.Attributes.Remove(currentAttribute); // remove script links else if ( //(attr == "href" || attr== "src" || attr == "dynsrc" || attr == "lowsrc") && val != null && val.Contains("javascript:")) node.Attributes.Remove(currentAttribute); // Remove CSS Expressions else if (attr == "style" && val != null && val.Contains("expression") || val.Contains("javascript:") || val.Contains("vbscript:")) node.Attributes.Remove(currentAttribute); } } } // Look through child nodes recursively if (node.HasChildNodes) { for (int i = node.ChildNodes.Count - 1; i >= 0; i--) { SanitizeHtmlNode(node.ChildNodes[i]); } } } } } Please note: Use this as a starting point only for your own parsing and review the code for your specific use case! If your needs are less lenient than mine were you can you can make this much stricter by not allowing src and href attributes or CSS links if your HTML doesn't allow it. You can also check links for external URLs and disallow those - lots of options. The code is simple enough to make it easy to extend to fit your use cases more specifically. It's also quite easy to make this code work using a WhiteList approach if you want to go that route. The code above is semi-generic for allowing full featured HTML fragments that only disallow script related content. The Sanitize method walks through each node of the document and then recursively drills into all of its children until the entire document has been traversed. Note that the code here uses an XmlTextWriter to write output - this is done to preserve XHTML style self-closing tags which are otherwise left as non-self-closing tags. The sanitizer code scans for blacklist elements and removes those elements not allowed. Note that the blacklist is configurable either in the instance class as a property or in the static method via the string parameter list. Additionally the code goes through each element's attributes and looks for a host of rules gleaned from some of the XSS cheat sheets listed at the end of the post. Clearly there are a lot more XSS vulnerabilities, but a lot of them apply to ancient browsers (IE6 and versions of Netscape) - many of these glaring holes (like CSS expressions - WTF IE?) have been removed in modern browsers. What a Pain To be honest this is NOT a piece of code that I wanted to write. I think building anything related to XSS is better left to people who have far more knowledge of the topic than I do. Unfortunately, I was unable to find a tool that worked even closely for me, or even provided a working base. For the project I was working on I had no choice and I'm sharing the code here merely as a base line to start with and potentially expand on for specific needs. It's sad that Microsoft Web Protection Library is currently such a train wreck - this is really something that should come from Microsoft as the systems vendor or possibly a third party that provides security tools. Luckily for my application we are dealing with a authenticated and validated users so the user base is fairly well known, and relatively small - this is not a wide open Internet application that's directly public facing. As I mentioned earlier in the post, if I had my way I would simply not allow this type of raw HTML input in the first place, and instead rely on a more controlled HTML input mechanism like MarkDown or even a good HTML Edit control that can provide some limits on what types of input are allowed. Alas in this case I was overridden and we had to go forward and allow *any* raw HTML posted. Sometimes I really feel sad that it's come this far - how many good applications and tools have been thwarted by fear of XSS (or worse) attacks? So many things that could be done *if* we had a more secure browser experience and didn't have to deal with every little script twerp trying to hack into Web pages and obscure browser bugs. So much time wasted building secure apps, so much time wasted by others trying to hack apps… We're a funny species - no other species manages to waste as much time, effort and resources as we humans do :-) Resources Code on GitHub Html Agility Pack XSS Cheat Sheet XSS Prevention Cheat Sheet Microsoft Web Protection Library (AntiXss) StackOverflow Links: http://stackoverflow.com/questions/341872/html-sanitizer-for-net http://blog.stackoverflow.com/2008/06/safe-html-and-xss/ http://code.google.com/p/subsonicforums/source/browse/trunk/SubSonic.Forums.Data/HtmlScrubber.cs?r=61© Rick Strahl, West Wind Technologies, 2005-2012Posted in Security HTML ASP.NET JavaScript Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (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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How to reduce iOS AVPlayer start delay

- by Bernt Habermeier

Note, for the below question: All assets are local on the device -- no network streaming is taking place. The videos contain audio tracks. I'm working on an iOS application that requires playing video files with minimum delay to start the video clip in question. Unfortunately we do not know what specific video clip is next until we actually need to start it up. Specifically: When one video clip is playing, we will know what the next set of (roughly) 10 video clips are, but we don't know which one exactly, until it comes time to 'immediately' play the next clip. What I've done to look at actual start delays is to call addBoundaryTimeObserverForTimes on the video player, with a time period of one millisecond to see when the video actually started to play, and I take the difference of that time stamp with the first place in the code that indicates which asset to start playing. From what I've seen thus-far, I have found that using the combination of AVAsset loading, and then creating an AVPlayerItem from that once it's ready, and then waiting for AVPlayerStatusReadyToPlay before I call play, tends to take between 1 and 3 seconds to start the clip. I've since switched to what I think is roughly equivalent: calling [AVPlayerItem playerItemWithURL:] and waiting for AVPlayerItemStatusReadyToPlay to play. Roughly same performance. One thing I'm observing is that the first AVPlayer item load is slower than the rest. Seems one idea is to pre-flight the AVPlayer with a short / empty asset before trying to play the first video might be of good general practice. [http://stackoverflow.com/questions/900461/slow-start-for-avaudioplayer-the-first-time-a-sound-is-played] I'd love to get the video start times down as much as possible, and have some ideas of things to experiment with, but would like some guidance from anyone that might be able to help. Update: idea 7, below, as-implemented yields switching times of around 500 ms. This is an improvement, but it it'd be nice to get this even faster. Idea 1: Use N AVPlayers (won't work) Using ~ 10 AVPPlayer objects and start-and-pause all ~ 10 clips, and once we know which one we really need, switch to, and un-pause the correct AVPlayer, and start all over again for the next cycle. I don't think this works, because I've read there is roughly a limit of 4 active AVPlayer's in iOS. There was someone asking about this on StackOverflow here, and found out about the 4 AVPlayer limit: fast-switching-between-videos-using-avfoundation Idea 2: Use AVQueuePlayer (won't work) I don't believe that shoving 10 AVPlayerItems into an AVQueuePlayer would pre-load them all for seamless start. AVQueuePlayer is a queue, and I think it really only makes the next video in the queue ready for immediate playback. I don't know which one out of ~10 videos we do want to play back, until it's time to start that one. ios-avplayer-video-preloading Idea 3: Load, Play, and retain AVPlayerItems in background (not 100% sure yet -- but not looking good) I'm looking at if there is any benefit to load and play the first second of each video clip in the background (suppress video and audio output), and keep a reference to each AVPlayerItem, and when we know which item needs to be played for real, swap that one in, and swap the background AVPlayer with the active one. Rinse and Repeat. The theory would be that recently played AVPlayer/AVPlayerItem's may still hold some prepared resources which would make subsequent playback faster. So far, I have not seen benefits from this, but I might not have the AVPlayerLayer setup correctly for the background. I doubt this will really improve things from what I've seen. Idea 4: Use a different file format -- maybe one that is faster to load? I'm currently using .m4v's (video-MPEG4) H.264 format. I have not played around with other formats, but it may well be that some formats are faster to decode / get ready than others. Possible still using video-MPEG4 but with a different codec, or maybe quicktime? Maybe a lossless video format where decoding / setup is faster? Idea 5: Combination of lossless video format + AVQueuePlayer If there is a video format that is fast to load, but maybe where the file size is insane, one idea might be to pre-prepare the first 10 seconds of each video clip with a version that is boated but faster to load, but back that up with an asset that is encoded in H.264. Use an AVQueuePlayer, and add the first 10 seconds in the uncompressed file format, and follow that up with one that is in H.264 which gets up to 10 seconds of prepare/preload time. So I'd get 'the best' of both worlds: fast start times, but also benefits from a more compact format. Idea 6: Use a non-standard AVPlayer / write my own / use someone else's Given my needs, maybe I can't use AVPlayer, but have to resort to AVAssetReader, and decode the first few seconds (possibly write raw file to disk), and when it comes to playback, make use of the raw format to play it back fast. Seems like a huge project to me, and if I go about it in a naive way, it's unclear / unlikely to even work better. Each decoded and uncompressed video frame is 2.25 MB. Naively speaking -- if we go with ~ 30 fps for the video, I'd end up with ~60 MB/s read-from-disk requirement, which is probably impossible / pushing it. Obviously we'd have to do some level of image compression (perhaps native openGL/es compression formats via PVRTC)... but that's kind crazy. Maybe there is a library out there that I can use? Idea 7: Combine everything into a single movie asset, and seekToTime One idea that might be easier than some of the above, is to combine everything into a single movie, and use seekToTime. The thing is that we'd be jumping all around the place. Essentially random access into the movie. I think this may actually work out okay: avplayer-movie-playing-lag-in-ios5 Which approach do you think would be best? So far, I've not made that much progress in terms of reducing the lag.

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Mobile enabled web apps with ASP.NET MVC 3 and jQuery Mobile

- by shiju

In my previous blog posts, I have demonstrated a simple web app using ASP.NET MVC 3 and EF Code First. In this post, I will be focus on making this application for mobile devices. A single web site will be used for both mobile browsers and desktop browsers. If users are accessing the web app from mobile browsers, users will be redirect to mobile specific pages and will get normal pages if users are accessing from desktop browsers. In this demo app, the mobile specific pages are maintained in an ASP.NET MVC Area named Mobile and mobile users will be redirect to MVC Area Mobile. Let’s add a new area named Mobile to the ASP.NET MVC app. For adding Area, right click the ASP.NET MVC project and select Area from Add option. Our mobile specific pages using jQuery Mobile will be maintained in the Mobile Area. ASP.NET MVC Global filter for redirecting mobile visitors to Mobile area Let’s add an ASP.NET MVC Global filter for redirecting mobile visitors to Mobile area. The below Global filter is taken from the sample app http://aspnetmobilesamples.codeplex.com/ created by the ASP.NET team. The below filer will redirect the Mobile visitors to an ASP.NET MVC Area Mobile. public class RedirectMobileDevicesToMobileAreaAttribute : AuthorizeAttribute { protected override bool AuthorizeCore(System.Web.HttpContextBase httpContext) { // Only redirect on the first request in a session if (!httpContext.Session.IsNewSession) return true; // Don't redirect non-mobile browsers if (!httpContext.Request.Browser.IsMobileDevice) return true; // Don't redirect requests for the Mobile area if (Regex.IsMatch(httpContext.Request.Url.PathAndQuery, "/Mobile($|/)")) return true; return false; } protected override void HandleUnauthorizedRequest(AuthorizationContext filterContext) { var redirectionRouteValues = GetRedirectionRouteValues(filterContext.RequestContext); filterContext.Result = new RedirectToRouteResult(redirectionRouteValues); } // Override this method if you want to customize the controller/action/parameters to which // mobile users would be redirected. This lets you redirect users to the mobile equivalent // of whatever resource they originally requested. protected virtual RouteValueDictionary GetRedirectionRouteValues(RequestContext requestContext) { return new RouteValueDictionary(new { area = "Mobile", controller = "Home", action = "Index" }); } } Let’s add the global filer RedirectMobileDevicesToMobileAreaAttribute to the global filter collection in the Application_Start() of Global.asax.cs file GlobalFilters.Filters.Add(new RedirectMobileDevicesToMobileAreaAttribute(), 1); Now your mobile visitors will be redirect to the Mobile area. But the browser detection logic in the RedirectMobileDevicesToMobileAreaAttribute filter will not be working in some modern browsers and some conditions. But the good news is that ASP.NET’s browser detection feature is extensible and will be greatly working with the open source framework 51Degrees.mobi. 51Degrees.mobi is a Browser Capabilities Provider that will be working with ASP.NET’s Request.Browser and will provide more accurate and detailed information. For more details visit the documentation page at http://51degrees.codeplex.com/documentation. Let’s add a reference to 51Degrees.mobi library using NuGet We can easily add the 51Degrees.mobi from NuGet and this will update the web.config for necessary configuartions. Mobile Web App using jQuery Mobile Framework jQuery Mobile Framework is built on top of jQuery that provides top-of-the-line JavaScript in a unified User Interface that works across the most-used smartphone web browsers and tablet form factors. It provides an easy way to develop user interfaces for mobile web apps. The current version of the framework is jQuery Mobile Alpha 3. We need to include the following files to use jQuery Mobile. The jQuery Mobile CSS file (jquery.mobile-1.0a3.min.css) The jQuery library (jquery-1.5.min.js) The jQuery Mobile library (jquery.mobile-1.0a3.min.js) Let’s add the required jQuery files directly from jQuery CDN . You can download the files and host them on your own server. jQuery Mobile page structure The basic jQuery Mobile page structure is given below <!DOCTYPE html> <html> <head> <title>Page Title</title> <link rel="stylesheet" href="http://code.jquery.com/mobile/1.0a3/jquery.mobile-1.0a1.min.css" /> <script src="http://code.jquery.com/jquery-1.5.min.js"></script> <script src="http://code.jquery.com/mobile/1.0a3/jquery.mobile-1.0a3.min.js"></script> </head> <body> <div data-role="page"> <div data-role="header"> <h1>Page Title</h1> </div> <div data-role="content"> <p>Page content goes here.</p> </div> <div data-role="footer"> <h4>Page Footer</h4> </div> </div> </body> </html> The data- attributes are the new feature of HTML5 so that jQuery Mobile will be working on browsers that supporting HTML 5. You can get a detailed browser support details from http://jquerymobile.com/gbs/ . In the Head section we have included the Core jQuery javascript file and jQuery Mobile Library and the core CSS Library for the UI Element Styling. These jQuery files are minified versions and will improve the performance of page load on Mobile Devices. The jQuery Mobile pages are identified with an element with the data-role="page" attribute inside the <body> tag. <div data-role="page"> </div> Within the "page" container, any valid HTML markup can be used, but for typical pages in jQuery Mobile, the immediate children of a "page" are div element with data-roles of "header", "content", and "footer". <div data-role="page"> <div data-role="header">...</div> <div data-role="content">...</div> <div data-role="footer">...</div> </div> The div data-role="content" holds the main content of the HTML page and will be used for making user interaction elements. The div data-role="header" is header part of the page and div data-role="footer" is the footer part of the page. Creating Mobile specific pages in the Mobile Area Let’s create Layout page for our Mobile area <!DOCTYPE html> <html> <head> <title>@ViewBag.Title</title> <link rel="stylesheet" href="http://code.jquery.com/mobile/1.0a3/jquery.mobile-1.0a3.min.css" /> <script src="http://code.jquery.com/jquery-1.5.min.js"></script> <script src="http://code.jquery.com/mobile/1.0a3/jquery.mobile-1.0a3.min.js"></script> </head> <body> @RenderBody() </body> </html> In the Layout page, I have given reference to jQuery Mobile JavaScript files and the CSS file. Let’s add an Index view page Index.chtml @{ ViewBag.Title = "Index"; } <div data-role="page"> <div data-role="header"> <h1>Expense Tracker Mobile</h1> </div> <div data-role="content"> <ul data-role="listview"> <li>@Html.Partial("_LogOnPartial")</li> <li>@Html.ActionLink("Home", "Index", "Home")</li> <li>@Html.ActionLink("Category", "Index", "Category")</li> <li>@Html.ActionLink("Expense", "Index", "Expense")</li> </ul> </div> <div data-role="footer"> Shiju Varghese | <a href="http://weblogs.asp.net/shijuvarghese">Blog </a> | <a href="http://twitter.com/shijucv">Twitter</a> </div> </div> In the Index page, we have used data-role “listview” for showing our content as List View Let’s create a data entry screen create.cshtml @model MyFinance.Domain.Category @{ ViewBag.Title = "Create Category"; } <div data-role="page"> <div data-role="header"> <h1>Create Category</h1> @Html.ActionLink("Home", "Index","Home",null, new { @class = "ui-btn-right" }) </div> <div data-role="content"> @using (Html.BeginForm("Create","Category",FormMethod.Post)) { <div data-role="fieldcontain"> @Html.LabelFor(model => model.Name) @Html.EditorFor(model => model.Name) <div> @Html.ValidationMessageFor(m => m.Name) </div> </div> <div data-role="fieldcontain"> @Html.LabelFor(model => model.Description) @Html.EditorFor(model => model.Description) </div> <div class="ui-body ui-body-b"> <button type="submit" data-role="button" data-theme="b">Save</button> </div> } </div> </div> In jQuery Mobile, the form elements should be placed inside the data-role="fieldcontain" The below screen shots show the pages rendered in mobile browser Index Page Create Page Source Code You can download the source code from http://efmvc.codeplex.com Summary We have created a single web app for desktop browsers and mobile browsers. If a user access the site from desktop browsers, users will get normal web pages and get mobile specific pages if users access from mobile browsers. If users are accessing the website from mobile devices, we will redirect to a ASP.NET MVC area Mobile. For redirecting to the Mobile area, we have used a Global filer for the redirection logic and used open source framework 51Degrees.mobi for the better support for mobile browser detection. In the Mobile area, we have created the pages using jQuery Mobile and users will get mobile friendly web pages. We can create great mobile web apps using ASP.NET MVC and jQuery Mobile Framework.

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Making WCF Output a single WSDL file for interop purposes.

- by Glav

By default, when WCF emits a WSDL definition for your services, it can often contain many links to others related schemas that need to be imported. For the most part, this is fine. WCF clients understand this type of schema without issue, and it conforms to the requisite standards as far as WSDL definitions go. However, some non Microsoft stacks will only work with a single WSDL file and require that all definitions for the service(s) (port types, messages, operation etc…) are contained within that single file. In other words, no external imports are supported. Some Java clients (to my working knowledge) have this limitation. This obviously presents a problem when trying to create services exposed for consumption and interop by these clients. Note: You can download the full source code for this sample from here To illustrate this point, lets say we have a simple service that looks like: Service Contract public interface IService1 { [OperationContract] [FaultContract(typeof(DataFault))] string GetData(DataModel1 model); [OperationContract] [FaultContract(typeof(DataFault))] string GetMoreData(DataModel2 model); } .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; } Service Implementation/Behaviour public class Service1 : IService1 { public string GetData(DataModel1 model) { return string.Format("Some Field was: {0} and another field was {1}", model.SomeField,model.AnotherField); } public string GetMoreData(DataModel2 model) { return string.Format("Name: {0}, age: {1}", model.Name, model.Age); } } .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; } Configuration File <system.serviceModel> <services> <service name="SingleWSDL_WcfService.Service1" behaviorConfiguration="SingleWSDL_WcfService.Service1Behavior">  <endpoint address ="" binding="wsHttpBinding" contract="SingleWSDL_WcfService.IService1" > ....... </services> <behaviors> <serviceBehaviors> <behavior name="SingleWSDL_WcfService.Service1Behavior"> ........ </behavior> </serviceBehaviors> </behaviors> </system.serviceModel> .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; } When WCF is asked to produce a WSDL for this service, it will produce a file that looks something like this (note: some sections omitted for brevity): <?xml version="1.0" encoding="utf-8" ?> - <wsdl:definitions name="Service1" targetNamespace="http://tempuri.org/" xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" ...... namespace definitions omitted for brevity + <wsp:Policy wsu:Id="WSHttpBinding_IService1_policy"> ... multiple policy items omitted for brevity </wsp:Policy> - <wsdl:types> - <xsd:schema targetNamespace="http://tempuri.org/Imports"> <xsd:import schemaLocation="http://localhost:2370/HostingSite/Service-default.svc?xsd=xsd0" namespace="http://tempuri.org/" /> <xsd:import schemaLocation="http://localhost:2370/HostingSite/Service-default.svc?xsd=xsd3" namespace="Http://SingleWSDL/Fault" /> <xsd:import schemaLocation="http://localhost:2370/HostingSite/Service-default.svc?xsd=xsd1" namespace="http://schemas.microsoft.com/2003/10/Serialization/" /> <xsd:import schemaLocation="http://localhost:2370/HostingSite/Service-default.svc?xsd=xsd2" namespace="http://SingleWSDL/Model1" /> <xsd:import schemaLocation="http://localhost:2370/HostingSite/Service-default.svc?xsd=xsd4" namespace="http://SingleWSDL/Model2" /> </xsd:schema> </wsdl:types> + <wsdl:message name="IService1_GetData_InputMessage"> .... </wsdl:message> - <wsdl:operation name="GetData"> ..... </wsdl:operation> - <wsdl:service name="Service1"> ....... </wsdl:service> </wsdl:definitions> The above snippet from the WSDL shows the external links and references that are generated by WCF for a relatively simple service. Note the xsd:import statements that reference external XSD definitions which are also generated by WCF. In order to get WCF to produce a single WSDL file, we first need to follow some good practices when it comes to WCF service definitions. Step 1: Define a namespace for your service contract. [ServiceContract(Namespace="http://SingleWSDL/Service1")] public interface IService1 { ...... } .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; } Normally you would not use a literal string and may instead define a constant to use in your own application for the namespace. When this is applied and we generate the WSDL, we get the following statement inserted into the document: <wsdl:import namespace="http://SingleWSDL/Service1" location="http://localhost:2370/HostingSite/Service-default.svc?wsdl=wsdl0" /> .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; } All the previous imports have gone. If we follow this link, we will see that the XSD imports are now in this external WSDL file. Not really any benefit for our purposes. Step 2: Define a namespace for your service behaviour [ServiceBehavior(Namespace = "http://SingleWSDL/Service1")] public class Service1 : IService1 { ...... } As you can see, the namespace of the service behaviour should be the same as the service contract interface to which it implements. Failure to do these tasks will cause WCF to emit its default http://tempuri.org namespace all over the place and cause WCF to still generate import statements. This is also true if the namespace of the contract and behaviour differ. If you define one and not the other, defaults kick in, and you’ll find extra imports generated. While each of the previous 2 steps wont cause any less import statements to be generated, you will notice that namespace definitions within the WSDL have identical, well defined names. Step 3: Define a binding namespace In the configuration file, modify the endpoint configuration line item to iunclude a bindingNamespace attribute which is the same as that defined on the service behaviour and service contract <endpoint address="" binding="wsHttpBinding" contract="SingleWSDL_WcfService.IService1" bindingNamespace="http://SingleWSDL/Service1"> .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; } However, this does not completely solve the issue. What this will do is remove the WSDL import statements like this one: <wsdl:import namespace="http://SingleWSDL/Service1" location="http://localhost:2370/HostingSite/Service-default.svc?wsdl" /> .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; } from the generated WSDL. Finally…. the magic…. Step 4: Use a custom endpoint behaviour to read in external imports and include in the main WSDL output. In order to force WCF to output a single WSDL with all the required definitions, we need to define a custom WSDL Export extension that can be applied to any endpoints. This requires implementing the IWsdlExportExtension and IEndpointBehavior interfaces and then reading in any imported schemas, and adding that output to the main, flattened WSDL to be output. Sounds like fun right…..? Hmmm well maybe not. This step sounds a little hairy, but its actually quite easy thanks to some kind individuals who have already done this for us. As far as I know, there are 2 available implementations that we can easily use to perform the import and “WSDL flattening”. WCFExtras which is on codeplex and FlatWsdl by Thinktecture. Both implementations actually do exactly the same thing with the imports and provide an endpoint behaviour, however FlatWsdl does a little more work for us by providing a ServiceHostFactory that we can use which automatically attaches the requisite behaviour to our endpoints for us. To use this in an IIS hosted service, we can modify the .SVC file to specify this ne factory to use like so: <%@ ServiceHost Language="C#" Debug="true" Service="SingleWSDL_WcfService.Service1" Factory="Thinktecture.ServiceModel.Extensions.Description.FlatWsdlServiceHostFactory" %> .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; } Within a service application or another form of executable such as a console app, we can simply create an instance of the custom service host and open it as we normally would as shown here: FlatWsdlServiceHost host = new FlatWsdlServiceHost(typeof(Service1)); host.Open(); And we are done. WCF will now generate one single WSDL file that contains all he WSDL imports and data/XSD imports. You can download the full source code for this sample from here Hope this has helped you. Note: Please note that I have not extensively tested this in a number of different scenarios so no guarantees there.

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