Search Results

Search found 2536 results on 102 pages for 'nested'.

Page 94/102 | < Previous Page | 90 91 92 93 94 95 96 97 98 99 100 101  | Next Page >

  • How can I improve my select query for storing large versioned data sets?

    - by Jason Francis
    At work, we build large multi-page web applications, consisting mostly of radio and check boxes. The primary purpose of each application is to gather data, but as users return to a page they have previously visited, we report back to them their previous responses. Worst-case scenario, we might have up to 900 distinct variables and around 1.5 million users. For several reasons, it makes sense to use an insert-only approach to storing the data (as opposed to update-in-place) so that we can capture historical data about repeated interactions with variables. The net result is that we might have several responses per user per variable. Our table to collect the responses looks something like this: CREATE TABLE [dbo].[results]( [id] [bigint] IDENTITY(1,1) NOT NULL, [userid] [int] NULL, [variable] [varchar](8) NULL, [value] [tinyint] NULL, [submitted] [smalldatetime] NULL) Where id serves as the primary key. Virtually every request results in a series of insert statements (one per variable submitted), and then we run a select to produce previous responses for the next page (something like this): SELECT t.id, t.variable, t.value FROM results t WITH (NOLOCK) WHERE t.userid = '2111846' AND (t.variable='internat' OR t.variable='veteran' OR t.variable='athlete') AND t.id IN (SELECT MAX(id) AS id FROM results WITH (NOLOCK) WHERE userid = '2111846' AND (t.variable='internat' OR t.variable='veteran' OR t.variable='athlete') GROUP BY variable) Which, in this case, would return the most recent responses for the variables "internat", "veteran", and "athlete" for user 2111846. We have followed the advice of the database tuning tools in indexing the tables, and against our data, this is the best-performing version of the select query that we have been able to come up with. Even so, there seems to be significant performance degradation as the table approaches 1 million records (and we might have about 150x that). We have a fairly-elegant solution in place for sharding the data across multiple tables which has been working quite well, but I am open for any advice about how I might construct a better version of the select query. We use this structure frequently for storing lots of independent data points, and we like the benefits it provides. So the question is, how can I improve the performance of the select query? I assume the nested select statement is a bad idea, but I have yet to find an alternative that performs as well. Thanks in advance. NB: Since we emphasize creating over reading in this case, and since we never update in place, there doesn't seem to be any penalty (and some advantage) for using the NOLOCK directive in this case.

    Read the article

  • Is it a good or bad practice to call instance methods from a java constructor?

    - by Steve
    There are several different ways I can initialize complex objects (with injected dependencies and required set-up of injected members), are all seem reasonable, but have various advantages and disadvantages. I'll give a concrete example: final class MyClass { private final Dependency dependency; @Inject public MyClass(Dependency dependency) { this.dependency = dependency; dependency.addHandler(new Handler() { @Override void handle(int foo) { MyClass.this.doSomething(foo); } }); doSomething(0); } private void doSomething(int foo) { dependency.doSomethingElse(foo+1); } } As you can see, the constructor does 3 things, including calling an instance method. I've been told that calling instance methods from a constructor is unsafe because it circumvents the compiler's checks for uninitialized members. I.e. I could have called doSomething(0) before setting this.dependency, which would have compiled but not worked. What is the best way to refactor this? Make doSomething static and pass in the dependency explicitly? In my actual case I have three instance methods and three member fields that all depend on one another, so this seems like a lot of extra boilerplate to make all three of these static. Move the addHandler and doSomething into an @Inject public void init() method. While use with Guice will be transparent, it requires any manual construction to be sure to call init() or else the object won't be fully-functional if someone forgets. Also, this exposes more of the API, both of which seem like bad ideas. Wrap a nested class to keep the dependency to make sure it behaves properly without exposing additional API:class DependencyManager { private final Dependency dependency; public DependecyManager(Dependency dependency) { ... } public doSomething(int foo) { ... } } @Inject public MyClass(Dependency dependency) { DependencyManager manager = new DependencyManager(dependency); manager.doSomething(0); } This pulls instance methods out of all constructors, but generates an extra layer of classes, and when I already had inner and anonymous classes (e.g. that handler) it can become confusing - when I tried this I was told to move the DependencyManager to a separate file, which is also distasteful because it's now multiple files to do a single thing. So what is the preferred way to deal with this sort of situation?

    Read the article

  • Inbreeding-immune database structure

    - by Nick Savage
    I have an application that requires a "simple" family tree. I would like to be able to perform queries that will give me data for an entire family given one id from a member in the family. I say simple because it does not need to take into account adoption or any other obscurities. The requirements for the application are as follows: Any two people will not be able to breed if they're from the same genetic line Needs to allow for the addition of new family lines (new people with no previous family) Need to be able to pull siblings, parents separately through queries I'm having trouble coming up with the proper structure for the database. So far I've come up with two solutions but they're not very reliable and will probably get out of hand quite quickly. Solution 1 involves placing a family_ids field on the people table and storing a list of unique family ids. Each time two people breed the lists are checked against each other to make sure no ids match and if everything checks out will merge the two lists and set that as the child's family_ids field. Example: Father (family_ids: (null)) breeds with Mother (family_ids: (213, 519)) -> Child (family_ids: (213, 519)) breeds with Random Person (family_ids: (813, 712, 122, 767)) -> Grandchild (family_ids: (213, 519, 813, 712, 122, 767)) And so on and so forth... The problem I see with this is the lists becoming unreasonably large as time goes on. Solution 2 uses cakephp's associations to declare: public $belongsTo = array( 'Father' => array( 'className' => 'User', 'foreignKey' => 'father_id' ), 'Mother' => array( 'className' => 'User', 'foreignKey' => 'mother_id' ) ); Now setting recursive to 2 will fetch the results of the mother and father, along with their mother and father, and so on and so forth all the way down the line. The problem with this route is that the data is in nested arrays and I'm unsure of how to efficiently work through the code. If anyone would be able to steer me in the direction of the most efficient way to handle what I want to achieve that would be tremendously helpful. Any and all help is greatly appreciated and I'll gladly answer any questions anyone has. Thanks a lot.

    Read the article

  • calling hibernate callback

    - by vrkmurali
    HibernateCallback callback=new HibernateCallback() { @Override public Object doInHibernate(Session session) throws HibernateException, SQLException { Transaction transaction=session.beginTransaction(); Query query2 = session.createSQLQuery( "select user_id,user_name from usermasterdao where user_id not in('select usermaster_id from LoginHistoryDAO where logindate between :fromdate and :todate')"); ((SQLQuery) query2).addEntity(UserMasterDAO.class); //query.setParameter("stockCode", "7277"); query2.setParameter("todate", toDate); query2.setParameter("fromdate", fromDate); List result2 = query2.list(); listofNotUsing=result2; System.out.println(result2.size()+"sizeeee"); transaction.commit(); return result2;}} while executing the command getting error like as follows com.vaadin.event.ListenerMethod$MethodException: Invocation of method notUsingButton in com.iton.ioffice.admin.LoginHistory failed. at com.vaadin.event.ListenerMethod.receiveEvent(ListenerMethod.java:530) at com.vaadin.event.EventRouter.fireEvent(EventRouter.java:164) at com.vaadin.ui.AbstractComponent.fireEvent(AbstractComponent.java:1219) at com.vaadin.ui.Button.fireClick(Button.java:567) at com.vaadin.ui.Button.changeVariables(Button.java:223) at com.vaadin.terminal.gwt.server.AbstractCommunicationManager.changeVariables(AbstractCommunicationManager.java:1460) at com.vaadin.terminal.gwt.server.AbstractCommunicationManager.handleVariableBurst(AbstractCommunicationManager.java:1404) at com.vaadin.terminal.gwt.server.AbstractCommunicationManager.handleVariables(AbstractCommunicationManager.java:1329) at com.vaadin.terminal.gwt.server.AbstractCommunicationManager.doHandleUidlRequest(AbstractCommunicationManager.java:761) at com.vaadin.terminal.gwt.server.CommunicationManager.handleUidlRequest(CommunicationManager.java:318) at com.vaadin.terminal.gwt.server.AbstractApplicationServlet.service(AbstractApplicationServlet.java:501) at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602) at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489) at java.lang.Thread.run(Thread.java:619) Caused by: org.springframework.orm.hibernate3.HibernateQueryException: could not locate named parameter [todate]; nested exception is org.hibernate.QueryPa rameterException: could not locate named parameter [todate] at org.springframework.orm.hibernate3.SessionFactoryUtils.convertHibernateAccessException(SessionFactoryUtils.java:656) at org.springframework.orm.hibernate3.HibernateAccessor.convertHibernateAccessException(HibernateAccessor.java:412) at org.springframework.orm.hibernate3.HibernateTemplate.doExecute(HibernateTemplate.java:411) at org.springframework.orm.hibernate3.HibernateTemplate.execute(HibernateTemplate.java:339) at com.iton.ioffice.admin.DAO.impl.UserServiceDAOImpl.outOfProcess(UserServiceDAOImpl.java:304) at com.iton.ioffice.admin.LoginHistory.notUsingButton(LoginHistory.java:298) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at com.vaadin.event.ListenerMethod.receiveEvent(ListenerMethod.java:520) ... 23 more Caused by: org.hibernate.QueryParameterException: could not locate named parameter [todate] at org.hibernate.engine.query.ParameterMetadata.getNamedParameterDescriptor(ParameterMetadata.java:99) at org.hibernate.engine.query.ParameterMetadata.getNamedParameterExpectedType(ParameterMetadata.java:105) at org.hibernate.impl.AbstractQueryImpl.determineType(AbstractQueryImpl.java:437) at org.hibernate.impl.AbstractQueryImpl.setParameter(AbstractQueryImpl.java:407) at com.iton.ioffice.admin.DAO.impl.UserServiceDAOImpl$4.doInHibernate(UserServiceDAOImpl.java:285) at org.springframework.orm.hibernate3.HibernateTemplate.doExecute(HibernateTemplate.java:406) ... 31 more please help me

    Read the article

  • ruby on rails photo upload problem

    - by dodo00700
    Hallo rails version 2.3.5 I'm learning rails and I run into a problem. I'm doing some nesting forms from the railscasts tutorials. I changed the text area into a data field to upload photos and everything is working. Now i have to display the uploaded pictures and i simply can't do it. I Tried everything I could find on the net but nothing worked. PROBLEM I have the Article controller which handles the article CRUD. inside the article new form there is nested a form for uploading images. article controller def code_image @image_data = Photo.find(params[:id]) @image = @image_data.binary_data send_data(@image, :type => @image_data.content_type, :filename => @image_data.filename, :disposition => 'inline') end photo model def image_file=(input_data) self.filename = input_data.original_filename self.content_type = input_data.content_type.chomp self.binary_data = input_data.read end articles/show.html.erb <%=h @article.title %> <%=h @article.body %> <% for photos in @article.photos %> <%= image_tag(url_for({:action => 'code_image', :id => @article.photos.id})) -%> <% end %> articles/_formnew.html.erb <% form_for (:article, @article, :url => {:action=>'create'}, :html=> {:multipart=>true}) do |f| %> <%= f.error_messages % <%= f.label :title %><br /> <%= f.text_field :title %><br /><br /> <%= f.label :body %><br /> <%= f.text_area :body, :style => 'width: 600px;' %><br /><br /> <% f.fields_for :photos do |builder|%> <%= builder.label :content, "Photo"%><br /> <%= builder.file_field :image_file %><br /> <% end %> <br /> <%= f.submit "Create" %> <% end % Thanks

    Read the article

  • Looping class, for template engine kind of thing

    - by tarnfeld
    Hey, I am updating my class Nesty so it's infinite but I'm having a little trouble.... Here is the class: <?php Class Nesty { // Class Variables private $text; private $data = array(); private $loops = 0; private $maxLoops = 0; public function __construct($text,$data = array(),$maxLoops = 5) { // Set the class vars $this->text = $text; $this->data = $data; $this->maxLoops = $maxLoops; } // Loop funtion private function loopThrough($data) { if( ($this->loops +1) > $this->maxLoops ) { die("ERROR: Too many loops!"); } else { $keys = array_keys($data); for($x = 0; $x < count($keys); $x++) { if(is_array($data[$keys[$x]])) { $this->loopThrough($data[$keys[$x]]); } else { return $data[$keys[$x]]; } } } } // Templater method public function template() { echo $this->loopThrough($this->data); } } ?> Here is the code you would use to create an instance of the class: <?php // The nested array $data = array( "person" => array( "name" => "Tom Arnfeld", "age" => 15 ), "product" => array ( "name" => "Cakes", "price" => array ( "single" => 59, "double" => 99 ) ), "other" => "string" ); // Retreive the template text $file = "TestData.tpl"; $fp = fopen($file,"r"); $text = fread($fp,filesize($file)); // Create the Nesty object require_once('Nesty.php'); $nesty = new Nesty($text,$data); // Save the newly templated text to a variable $message $message = $nesty->template(); // Print out $message on the page echo("<pre>".$message."</pre>"); ?> Any ideas?

    Read the article

  • How do I access the enumerated item with an indexer and assign array string to it for display?

    - by g00p3k
    EDITED: Updated 3/23/09. See rest of post at bottom. I'm still having trouble with the indexer. Anymore help or examples would really help me out. Write a class, MyCourses, that contains an enumeration of all the courses that you are currently taking. This enum should be nested inside of your class MyCourses. Your class should also have an array field that provides a short description (as a String) of each of your courses. Write an indexer that takes one of your enumerated courses as an index and returns the String description of the course. Write a class MyFriends that contains an indexer that provides access to the names of your friends. namespace IT274_Unit4Project { public class MyCourses { // enumeration that contains an enumeration of all the courses that // student is currently enrolled in public enum CourseName {IT274= 0,CS210 = 1} // array field that provides short description for each of classes, // returns string description of the course private String[] courseDescription = {"Intermediate C#: Teaches intermediate elements of C# programming and software design", "Career Development Strategies: Teaches principles for career progression, resume preparation, and overall self anaylsis"}; // indexer that takes one of the enumerated courses as an index // and returns the String description of the course public String this[CourseName index] { get { if (index == 1) return courseDescription[0]; else return courseDescription[1]; } set { if (index == 1) courseDescription[0] = value; else courseDescription[1] = value; } } } }//end public class MyCourses I'm working on this homework project and having trouble understanding the text explaining how to correctly take the accessed value of the enumeration and then apply the string array value to it. Can you please help me understand this? The text we are using is very difficult and poorly written for a beginner to understand, so I'm kind of on my own here. I've got the first parts written, but need some help on the accessing of the enumeration value and assigning, i think i'm close, but don't understand how to properly get and set the values on this. Please do not provide me with direct code answers, unless a MSDN style explanation that is generalized and not specific to my project. ie: public class MyClass { string field1; string field2; //properties public string Value1 get etc... Thanks!

    Read the article

  • jquery .find to get the text in a <li>

    - by Chris
    So I have a series of 2 nested ul's. When you click on the text (which is in an a tag) in the li, my page makes that editable and adds a save button. clicking the save button needs to give me back the new text inside that li and the id of that li. The id is not a problem. I'm trying to use jQuery's .find to select that anchor tag (which is successful) but i can't seem to get the text from it. Here is an example of the first list and it's sublists. <ul class='lists'> <li class='list1'> <a class='a list' id='list1'> List 1 Name</a> <img id='savelist1id' onClick="SaveName(this.parentNode.id)" src='save.jpg'> <ul class='list1subs'> <li class='sub1'> <a class='a sub' id='sub1id'> Sub 1 Name</a> <img id='savesub1id' onClick="SaveName(this.parentNode.id)" src='save.jpg'> </li> <li class='sub3'> <a class='a sub' id='sub2id'> Sub 2 Name</a> <img id='savesub2id' onClick="SaveName(this.parentNode.id)" src='save.jpg'> </li> <li class='sub2'> <a class='a sub' id='sub3id'> Sub 3 Name</a> <img id='savesub3id' onClick="SaveName(this.parentNode.id)" src='save.jpg'> </li> </ul> </li> </ul> Here's the code for identifying which save button you clicked. function SaveName(parentid){ $('li').find('a').each(function(){ if (this.id == parentid){ alert(this.id+' '+this.text) } } }); I am wanting this.text to show me the text inside the anchor tags. Help, please?

    Read the article

  • How to get all captures of subgroup matches with preg_match_all()?

    - by hakre
    Update/Note: I think what I'm probably looking for is to get the captures of a group in PHP. Referenced: PCRE regular expressions using named pattern subroutines. (Read carefully:) I have a string that contains a variable number of segments (simplified): $subject = 'AA BB DD '; // could be 'AA BB DD CC EE ' as well I would like now to match the segments and return them via the matches array: $pattern = '/^(([a-z]+) )+$/i'; $result = preg_match_all($pattern, $subject, $matches); This will only return the last match for the capture group 2: DD. Is there a way that I can retrieve all subpattern captures (AA, BB, DD) with one regex execution? Isn't preg_match_all suitable for this? This question is a generalization. Both the $subject and $pattern are simplified. Naturally with such the general list of AA, BB, .. is much more easy to extract with other functions (e.g. explode) or with a variation of the $pattern. But I'm specifically asking how to return all of the subgroup matches with the preg_...-family of functions. For a real life case imagine you have multiple (nested) level of a variant amount of subpattern matches. Example This is an example in pseudo code to describe a bit of the background. Imagine the following: Regular definitions of tokens: CHARS := [a-z]+ PUNCT := [.,!?] WS := [ ] $subject get's tokenized based on these. The tokenization is stored inside an array of tokens (type, offset, ...). That array is then transformed into a string, containing one character per token: CHARS -> "c" PUNCT -> "p" WS -> "s" So that it's now possible to run regular expressions based on tokens (and not character classes etc.) on the token stream string index. E.g. regex: (cs)?cp to express one or more group of chars followed by a punctuation. As I now can express self-defined tokens as regex, the next step was to build the grammar. This is only an example, this is sort of ABNF style: words = word | (word space)+ word word = CHARS+ space = WS punctuation = PUNCT If I now compile the grammar for words into a (token) regex I would like to have naturally all subgroup matches of each word. words = (CHARS+) | ( (CHARS+) WS )+ (CHARS+) # words resolved to tokens words = (c+)|((c+)s)+c+ # words resolved to regex I could code until this point. Then I ran into the problem that the sub-group matches did only contain their last match. So I have the option to either create an automata for the grammar on my own (which I would like to prevent to keep the grammar expressions generic) or to somewhat make preg_match working for me somehow so I can spare that. That's basically all. Probably now it's understandable why I simplified the question. Related: pcrepattern man page Get repeated matches with preg_match_all()

    Read the article

  • How can I get all children from a parent row in the same table?

    - by Johnny Freeman
    Let's say I have a table called my_table that looks like this: id | name | parent_id 1 | Row 1 | NULL 2 | Row 2 | NULL 3 | Row 3 | 1 4 | Row 4 | 1 5 | Row 5 | NULL 6 | Row 6 | NULL 7 | Row 7 | 8 8 | Row 8 | NULL 9 | Row 9 | 4 10 | Row 10 | 4 Basically I want my final array in PHP to look like this: Array ( [0] => Array ( [name] => Row 1 [children] => Array ( [0] => Array ( [name] => Row 3 [children] => ) [1] => Array ( [name] => Row 4 [children] => Array ( [0] => Array ( [name] => Row 9 [children] => ) [1] => Array ( [name] => Row 10 [children] => ) ) ) ) ) [1] => Array ( [name] => Row 2 [children] => ) [2] => Array ( [name] => Row 5 [children] => ) [3] => Array ( [name] => Row 6 [children] => ) [4] => Array ( [name] => Row 8 [children] => Array ( [0] => Array ( [name] => Row 7 [children] => ) ) ) ) So, I want it to get all of the rows where parent_id is null, then find all nested children recursively. Now here's the part that I'm having trouble with: How can this be done with 1 call to the database? I'm sure I could do it with a simple select statement and then have PHP make the array look like this but I'm hoping this can be done with some kind of fancy db joining or something like that. Any takers?

    Read the article

  • Freemarker rendering differently on IE8

    - by scphantm
    we have a template that uses this for the record line <input type="${inputType}" name="${variableName}.code" id="${variable}.${vnum}.${answer.code}" class="checkbox" value="${answer.code}" [#nested/] [#if (answer.textLength > 0) && scripting]onchange="showOtherBox( this, '${variable}.[#if descriptionHack]${variableNumber}[#else]${vnum}[/#if].${answer.code}.description' )"[/#if] [#if showValues && (existing == answer.code)]checked="checked"[/#if]/> On IE8 it renders as this <span class="field"> <INPUT id=responses.8.L class=checkbox value=L type=checkbox name="responses['8'].answers['L'].code"> <LABEL for=responses.8.L>Award(s) for special accomplishment or performance related to activity participation (please list)</LABEL> <TEXTAREA id=responses.8.L.description class=" visible" rows=4 cols=60 name="responses['8'].answers['L'].description"></TEXTAREA> </span> and on every other browser we tried, it renders as this <span class="field"> <input type="checkbox" name="responses['8'].answers['L'].code" id="responses.8.L" class="checkbox" value="L" onchange="showOtherBox( this, 'responses.8.L.description' )"> <label for="responses.8.L">Award(s) for special accomplishment or performance related to activity participation (please list)</label> <textarea rows="4" cols="60" name="responses['8'].answers['L'].description" id="responses.8.L.description" class="visible" classname="visible"></textarea> </span> The difference being that in the FTL script, the if statement [#if (answer.textLength > 0) && scripting] is true for everything except IE. In IE8 its false for some reason and therefore it does not put the OnChange javascript event on the input tag. Has anyone seen anything like this before? we are using Freemarker 2.3.9 Update, it kinda works if i turn compatibility mode on for IE8. but not exactly. when i do that, the onchange event doesn't fire until the check box loses focus. which is very different than everything else. Is there a quick way to fix this without too much trouble? i suppose i could put something in that says if ie8, insert onclick instead of onchange. that may work, but i would need an authorization from the client to fix it like that.

    Read the article

  • C# A simple Hangman game

    - by Radostin Angelov
    I'm trying to create a simple Hangman game and i have gotten so far, to make it read all words from a text file, but I don't know how to make the code work for every single word. I have another project, working with 3/4 words but with repeating nested if statements. I want to make it as shorter as possible. This is the code i have so far : using System; using System.Linq; class Program { static void Main() { string[] words = System.IO.File.ReadAllLines(@"C:\Users\ADMIN\Desktop\Letters\Letters.txt"); int LengthOfArray = words.Length; Random rnd = new Random(); int random = rnd.Next(1, 3); char[] letters = words[random].ToCharArray(); bool WordIsHidden = true; char hiddenChar = '_'; char GuessedLetter = hiddenChar; var retry = true; while (retry = true) { Console.WriteLine(letters); letters = GuessedLetter.ToString().ToCharArray(); for (int i = 1; i <= LengthOfArray; i++) { Console.Write("{0} ", GuessedLetter); } Console.WriteLine("Enter a letter!"); char letter = char.Parse(Console.ReadLine()); if (words[random].Contains<char>(letter)) { WordIsHidden = false; GuessedLetter = letter; Console.Write(letters); } else { if (WordIsHidden == true) { Console.Write("You guessed wrong!"); } } } } } Also I'm trying to make the game show each letter, the user has guessed on it's corresponding position, but now the letter is one line higher than the rest of the word and it's not in it's right position. Edited: Here is the result : cat ___Enter a letter! a __ aaaEnter a letter! t aa tttEnter a letter! IF anyone have a clue for where does this come from and how can I fix it, any help will be greatly appreciated.

    Read the article

  • jQuery: How to get the first “td” in all rows

    - by bobby
    I have a table, and I want get the first “td” in all rows. My jquery here: $("table.SimpleTable tr td:first-child").css('background-color','red'); and my HTML here: <table class='SimpleTable' border="1" ID="Table1"> <tr> <td>Left</td> <td>Right</td> </tr> <tr> <td>Left</td> <td>Right</td> </tr> <tr> <td>Left</td> <td>Right</td> </tr> <tr> <td>Left</td> <td> <table border="1" ID="Table2"> <tr> <td>AAA</td> <td>AAA</td> <td>AAA</td> </tr> </table> </td> </tr> <tr> <td>Left</td> <td> <table border="1" ID="Table3"> <tr> <td>BBB</td> <td>BBB</td> <td>BBB</td> </tr> </table> </td> </tr> </table> The problem here it get the first "td" in the nested table of the second "td". Please help me!

    Read the article

  • Pass variables between separate instances of ruby (without writing to a text file or database)

    - by boulder_ruby
    Lets say I'm running a long worker-script in one of several open interactive rails consoles. The script is updating columns in a very, very, very large table of records. I've muted the ActiveRecord logger to speed up the process, and instruct the script to output some record of progress so I know how roughly how long the process is going to take. That is what I am currently doing and it would look something like this: ModelName.all.each_with_index do |r, i| puts i if i % 250 ...runs some process... r.save end Sometimes its two nested arrays running, such that there would be multiple iterators and other things running all at once. Is there a way that I could do something like this and access that variable from a separate rails console? (such that the variable would be overwritten every time the process is run without much slowdown) records = ModelName.all $total = records.count records.each_with_index do |r, i| $i = i ...runs some process... r.save end meanwhile mid-process in other console puts "#{($i/$total * 100).round(2)}% complete" #=> 67.43% complete I know passing global variables from one separate instance of ruby to the next doesn't work. I also just tried this to no effect as well unix console 1 $X=5 echo {$X} #=> 5 unix console 2 echo {$X} #=> "" Lastly, I also know using global variables like this is a major software design pattern no-no. I think that's reasonable, but I'd still like to know how to break that rule if I'd like. Writing to a text file obviously would work. So would writing to a separate database table or something. That's not a bad idea. But the really cool trick would be sharing a variable between two instances without writing to a text file or database column. What would this be called anyway? Tunneling? I don't quite know how to tag this question. Maybe bad-idea is one of them. But honestly design-patterns isn't what this question is about.

    Read the article

  • How to iterate a list inside a list in java?

    - by user2142786
    Hi i have two value object classes . package org.array; import java.util.List; public class Father { private String name; private int age ; private List<Children> Childrens; public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public List<Children> getChildrens() { return Childrens; } public void setChildrens(List<Children> childrens) { Childrens = childrens; } } second is for children package org.array; public class Children { private String name; private int age ; public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } } and i want to print there value i nested a list inside a list here i am putting only a single value inside the objects while in real i have many values . so i am nesting list of children inside father list. how can i print or get the value of child and father both. here is my logic. package org.array; import java.util.ArrayList; import java.util.Iterator; import java.util.List; public class ArrayDemo { public static void main(String[] args) { List <Father> fatherList = new ArrayList<Father>(); Father father = new Father(); father.setName("john"); father.setAge(25); fatherList.add(father); List <Children> childrens = new ArrayList<Children>(); Children children = new Children(); children.setName("david"); children.setAge(2); childrens.add(children); father.setChildrens(childrens); fatherList.add(father); Iterator<Father> iterator = fatherList.iterator(); while (iterator.hasNext()) { System.out.println(iterator.toString()); } } }

    Read the article

  • Can't start managed server in Oracle Weblogic 10.3.2

    - by Neuquino
    I installed Oracle SOA Suite 11g. I start the NodeManager successfully. I start the AdminServer successfully. When I go to start the soa serve (soa_server1) I get this output: NMProcess: <Mar 15, 2010 3:33:30 PM> <WARNING> <Exception while starting server 'soa_server1'> NMProcess: java.io.IOException: Server failed to start up. See server output log for more details. NMProcess: at weblogic.nodemanager.server.ServerManager.start(ServerManager.java:331) NMProcess: at weblogic.nodemanager.server.Handler.handleStart(Handler.java:541) NMProcess: at weblogic.nodemanager.server.Handler.handleCommand(Handler.java:116) NMProcess: at weblogic.nodemanager.server.Handler.run(Handler.java:70) NMProcess: at java.lang.Thread.run(Thread.java:619) NMProcess: NMProcess: Mar 15, 2010 3:33:30 PM weblogic.nodemanager.server.Handler handleStart NMProcess: WARNING: Exception while starting server 'soa_server1' NMProcess: java.io.IOException: Server failed to start up. See server output log for more details. NMProcess: at weblogic.nodemanager.server.ServerManager.start(ServerManager.java:331) NMProcess: at weblogic.nodemanager.server.Handler.handleStart(Handler.java:541) NMProcess: at weblogic.nodemanager.server.Handler.handleCommand(Handler.java:116) NMProcess: at weblogic.nodemanager.server.Handler.run(Handler.java:70) NMProcess: at java.lang.Thread.run(Thread.java:619) Error Starting server soa_server1: weblogic.nodemanager.NMException: Exception while starting server 'soa_server1' In the log file I've got this: Enter username to boot WebLogic server:Enter password to boot WebLogic server: There are 1 nested errors: weblogic.management.ManagementException: Booting as admin server, but servername, soa_server1, does not match the admin server name, AdminServer at weblogic.management.provider.internal.RuntimeAccessService.start(RuntimeAccessService.java:67) at weblogic.t3.srvr.ServerServicesManager.startService(ServerServicesManager.java:461) at weblogic.t3.srvr.ServerServicesManager.startInStandbyState(ServerServicesManager.java:166) at weblogic.t3.srvr.T3Srvr.initializeStandby(T3Srvr.java:749) at weblogic.t3.srvr.T3Srvr.startup(T3Srvr.java:488) at weblogic.t3.srvr.T3Srvr.run(T3Srvr.java:446) at weblogic.Server.main(Server.java:67) > <Mar 15, 2010 3:33:30 PM ART> <Notice> <WebLogicServer> <BEA-000365> <Server state changed to FAILED> <Mar 15, 2010 3:33:30 PM ART> <Error> <WebLogicServer> <BEA-000383> <A critical service failed. The server will shut itself down> <Mar 15, 2010 3:33:30 PM ART> <Notice> <WebLogicServer> <BEA-000365> <Server state changed to FORCE_SHUTTING_DOWN> <Mar 15, 2010 3:33:30 PM> <FINEST> <NodeManager> <Waiting for the process to die: 31144> <Mar 15, 2010 3:33:30 PM> <INFO> <NodeManager> <Server failed during startup so will not be restarted> <Mar 15, 2010 3:33:30 PM> <FINEST> <NodeManager> <runMonitor returned, setting finished=true and notifying waiters> Do you have any clue of what is happening? If you need more info, just ask for it. thanks in advance

    Read the article

  • multiple puppet masters

    - by Oli
    I would like to set up an additional puppet master but have the CA server handled by only 1 puppet master. I have set this up as per the documentation here: http://docs.puppetlabs.com/guides/scaling_multiple_masters.html I have configured my second puppet master as follows: [main] ... ca = false ca_server = puppet-master1.test.net I am using passenger so I am a bit confused how the virtual-host.conf file should look for my second puppet-master2.test.net. Here is mine (updated as per Shane Maddens answer): LoadModule passenger_module /usr/lib/ruby/gems/1.8/gems/passenger-3.0.18/ext/apache2/mod_passenger.so PassengerRoot /usr/lib/ruby/gems/1.8/gems/passenger-3.0.18 PassengerRuby /usr/bin/ruby Listen 8140 <VirtualHost *:8140> ProxyPassMatch ^/([^/]+/certificate.*)$ https://puppet-master1.test.net:8140/$1 SSLEngine on SSLProtocol -ALL +SSLv3 +TLSv1 SSLCipherSuite ALL:!ADH:RC4+RSA:+HIGH:+MEDIUM:-LOW:-SSLv2:-EXP SSLCertificateFile /var/lib/puppet/ssl/certs/puppet-master2.test.net.pem SSLCertificateKeyFile /var/lib/puppet/ssl/private_keys/puppet-master2.test.net.pem #SSLCertificateChainFile /var/lib/puppet/ssl/ca/ca_crt.pem #SSLCACertificateFile /var/lib/puppet/ssl/ca/ca_crt.pem # If Apache complains about invalid signatures on the CRL, you can try disabling # CRL checking by commenting the next line, but this is not recommended. #SSLCARevocationFile /var/lib/puppet/ssl/ca/ca_crl.pem SSLVerifyClient optional SSLVerifyDepth 1 # The `ExportCertData` option is needed for agent certificate expiration warnings SSLOptions +StdEnvVars +ExportCertData # This header needs to be set if using a loadbalancer or proxy RequestHeader unset X-Forwarded-For RequestHeader set X-SSL-Subject %{SSL_CLIENT_S_DN}e RequestHeader set X-Client-DN %{SSL_CLIENT_S_DN}e RequestHeader set X-Client-Verify %{SSL_CLIENT_VERIFY}e DocumentRoot /etc/puppet/rack/public/ RackBaseURI / <Directory /etc/puppet/rack/> Options None AllowOverride None Order allow,deny allow from all </Directory> </VirtualHost> I have commented out the #SSLCertificateChainFile, #SSLCACertificateFile & #SSLCARevocationFile - this is not a CA server so not sure I need this. How would I get passenger to work with these? I would like to use ProxyPassMatch which I have configured as per the documentation. I don't want to specify a ca server in every puppet.conf file. I am getting this error when trying to get create a cert from a puppet client pointing to the second puppet master server (puppet-master2.test.net): [root@puppet-client2 ~]# puppet agent --test Error: Could not request certificate: Could not intern from s: nested asn1 error Exiting; failed to retrieve certificate and waitforcert is disabled On the puppet client I have this [main] server = puppet-master2.test.net What have I missed? -- update Here is a new virtual host file on my secondary puppet master. Is this correct? I have SSL turned off? LoadModule passenger_module /usr/lib/ruby/gems/1.8/gems/passenger-3.0.18/ext/apache2/mod_passenger.so PassengerRoot /usr/lib/ruby/gems/1.8/gems/passenger-3.0.18 PassengerRuby /usr/bin/ruby # you probably want to tune these settings PassengerHighPerformance on PassengerMaxPoolSize 12 PassengerPoolIdleTime 1500 # PassengerMaxRequests 1000 PassengerStatThrottleRate 120 RackAutoDetect Off RailsAutoDetect Off Listen 8140 <VirtualHost *:8140> SSLEngine off ProxyPassMatch ^/([^/]+/certificate.*)$ https://puppet-master1.test.net:8140/$1 # Obtain Authentication Information from Client Request Headers SetEnvIf X-Client-Verify "(.*)" SSL_CLIENT_VERIFY=$1 SetEnvIf X-SSL-Client-DN "(.*)" SSL_CLIENT_S_DN=$1 DocumentRoot /etc/puppet/rack/public/ RackBaseURI / <Directory /etc/puppet/rack/> Options None AllowOverride None Order allow,deny allow from all </Directory> </VirtualHost> Cheers, Oli

    Read the article

  • HttpContext.Items and Server.Transfer/Execute

    - by Rick Strahl
    A few days ago my buddy Ben Jones pointed out that he ran into a bug in the ScriptContainer control in the West Wind Web and Ajax Toolkit. The problem was basically that when a Server.Transfer call was applied the script container (and also various ClientScriptProxy script embedding routines) would potentially fail to load up the specified scripts. It turns out the problem is due to the fact that the various components in the toolkit use request specific singletons via a Current property. I use a static Current property tied to a Context.Items[] entry to handle this type of operation which looks something like this: /// <summary> /// Current instance of this class which should always be used to /// access this object. There are no public constructors to /// ensure the reference is used as a Singleton to further /// ensure that all scripts are written to the same clientscript /// manager. /// </summary> public static ClientScriptProxy Current { get { if (HttpContext.Current == null) return new ClientScriptProxy(); ClientScriptProxy proxy = null; if (HttpContext.Current.Items.Contains(STR_CONTEXTID)) proxy = HttpContext.Current.Items[STR_CONTEXTID] as ClientScriptProxy; else { proxy = new ClientScriptProxy(); HttpContext.Current.Items[STR_CONTEXTID] = proxy; } return proxy; } } The proxy is attached to a Context.Items[] item which makes the instance Request specific. This works perfectly fine in most situations EXCEPT when you’re dealing with Server.Transfer/Execute requests. Server.Transfer doesn’t cause Context.Items to be cleared so both the current transferred request and the original request’s Context.Items collection apply. For the ClientScriptProxy this causes a problem because script references are tracked on a per request basis in Context.Items to check for script duplication. Once a script is rendered an ID is written into the Context collection and so considered ‘rendered’: // No dupes - ref script include only once if (HttpContext.Current.Items.Contains( STR_SCRIPTITEM_IDENTITIFIER + fileId ) ) return; HttpContext.Current.Items.Add(STR_SCRIPTITEM_IDENTITIFIER + fileId, string.Empty); where the fileId is the script name or unique identifier. The problem is on the Transferred page the item will already exist in Context and so fail to render because it thinks the script has already rendered based on the Context item. Bummer. The workaround for this is simple once you know what’s going on, but in this case it was a bitch to track down because the context items are used in many places throughout this class. The trick is to determine when a request is transferred and then removing the specific keys. The first issue is to determine if a script is in a Trransfer or Execute call: if (HttpContext.Current.CurrentHandler != HttpContext.Current.Handler) Context.Handler is the original handler and CurrentHandler is the actual currently executing handler that is running when a Transfer/Execute is active. You can also use Context.PreviousHandler to get the last handler and chain through the whole list of handlers applied if Transfer calls are nested (dog help us all for the person debugging that). For the ClientScriptProxy the full logic to check for a transfer and remove the code looks like this: /// <summary> /// Clears all the request specific context items which are script references /// and the script placement index. /// </summary> public void ClearContextItemsOnTransfer() { if (HttpContext.Current != null) { // Check for Server.Transfer/Execute calls - we need to clear out Context.Items if (HttpContext.Current.CurrentHandler != HttpContext.Current.Handler) { List<string> Keys = HttpContext.Current.Items.Keys.Cast<string>().Where(s => s.StartsWith(STR_SCRIPTITEM_IDENTITIFIER) || s == STR_ScriptResourceIndex).ToList(); foreach (string key in Keys) { HttpContext.Current.Items.Remove(key); } } } } along with a small update to the Current property getter that sets a global flag to indicate whether the request was transferred: if (!proxy.IsTransferred && HttpContext.Current.Handler != HttpContext.Current.CurrentHandler) { proxy.ClearContextItemsOnTransfer(); proxy.IsTransferred = true; } return proxy; I know this is pretty ugly, but it works and it’s actually minimal fuss without affecting the behavior of the rest of the class. Ben had a different solution that involved explicitly clearing out the Context items and replacing the collection with a manually maintained list of items which also works, but required changes through the code to make this work. In hindsight, it would have been better to use a single object that encapsulates all the ‘persisted’ values and store that object in Context instead of all these individual small morsels. Hindsight is always 20/20 though :-}. If possible use Page.Items ClientScriptProxy is a generic component that can be used from anywhere in ASP.NET, so there are various methods that are not Page specific on this component which is why I used Context.Items, rather than the Page.Items collection.Page.Items would be a better choice since it will sidestep the above Server.Transfer nightmares as the Page is reloaded completely and so any new Page gets a new Items collection. No fuss there. So for the ScriptContainer control, which has to live on the page the behavior is a little different. It is attached to Page.Items (since it’s a control): /// <summary> /// Returns a current instance of this control if an instance /// is already loaded on the page. Otherwise a new instance is /// created, added to the Form and returned. /// /// It's important this function is not called too early in the /// page cycle - it should not be called before Page.OnInit(). /// /// This property is the preferred way to get a reference to a /// ScriptContainer control that is either already on a page /// or needs to be created. Controls in particular should always /// use this property. /// </summary> public static ScriptContainer Current { get { // We need a context for this to work! if (HttpContext.Current == null) return null; Page page = HttpContext.Current.CurrentHandler as Page; if (page == null) throw new InvalidOperationException(Resources.ERROR_ScriptContainer_OnlyWorks_With_PageBasedHandlers); ScriptContainer ctl = null; // Retrieve the current instance ctl = page.Items[STR_CONTEXTID] as ScriptContainer; if (ctl != null) return ctl; ctl = new ScriptContainer(); page.Form.Controls.Add(ctl); return ctl; } } The biggest issue with this approach is that you have to explicitly retrieve the page in the static Current property. Notice again the use of CurrentHandler (rather than Handler which was my original implementation) to ensure you get the latest page including the one that Server.Transfer fired. Server.Transfer and Server.Execute are Evil All that said – this fix is probably for the 2 people who are crazy enough to rely on Server.Transfer/Execute. :-} There are so many weird behavior problems with these commands that I avoid them at all costs. I don’t think I have a single application that uses either of these commands… Related Resources Full source of ClientScriptProxy.cs (repository) Part of the West Wind Web Toolkit Static Singletons for ASP.NET Controls Post © Rick Strahl, West Wind Technologies, 2005-2010Posted in ASP.NET  

    Read the article

  • AutoMapper MappingFunction from Source Type of NameValueCollection

    - by REA_ANDREW
    I have had a situation arise today where I need to construct a complex type from a source of a NameValueCollection.  A little while back I submitted a patch for the Agatha Project to include REST (JSON and XML) support for the service contract.  I realized today that as useful as it is, it did not actually support true REST conformance, as REST should support GET so that you can use JSONP from JavaScript directly meaning you can query cross domain services.  My original implementation for POX and JSON used the POST method and this immediately rules out JSONP as from reading, JSONP only works with GET Requests. This then raised another issue.  The current operation contract of Agatha and one of its main benefits is that you can supply an array of Request objects in a single request, limiting the about of server requests you need to make.  Now, at the present time I am thinking that this will not be the case for the REST imlementation but will yield the benefits of the fact that : The same Request objects can be used for SOAP and RST (POX, JSON) The construct of the JavaScript functions will be simpler and more readable It will enable the use of JSONP for cross domain REST Services The current contract for the Agatha WcfRequestProcessor is at time of writing the following: [ServiceContract] public interface IWcfRequestProcessor { [OperationContract(Name = "ProcessRequests")] [ServiceKnownType("GetKnownTypes", typeof(KnownTypeProvider))] [TransactionFlow(TransactionFlowOption.Allowed)] Response[] Process(params Request[] requests); [OperationContract(Name = "ProcessOneWayRequests", IsOneWay = true)] [ServiceKnownType("GetKnownTypes", typeof(KnownTypeProvider))] void ProcessOneWayRequests(params OneWayRequest[] requests); }   My current proposed solution, and at the very early stages of my concept is as follows: [ServiceContract] public interface IWcfRestJsonRequestProcessor { [OperationContract(Name="process")] [ServiceKnownType("GetKnownTypes", typeof(KnownTypeProvider))] [TransactionFlow(TransactionFlowOption.Allowed)] [WebGet(UriTemplate = "process/{name}/{*parameters}", BodyStyle = WebMessageBodyStyle.WrappedResponse, ResponseFormat = WebMessageFormat.Json)] Response[] Process(string name, NameValueCollection parameters); [OperationContract(Name="processoneway",IsOneWay = true)] [ServiceKnownType("GetKnownTypes", typeof(KnownTypeProvider))] [WebGet(UriTemplate = "process-one-way/{name}/{*parameters}", BodyStyle = WebMessageBodyStyle.WrappedResponse, ResponseFormat = WebMessageFormat.Json)] void ProcessOneWayRequests(string name, NameValueCollection parameters); }   Now this part I have not yet implemented, it is the preliminart step which I have developed which will allow me to take the name of the Request Type and the NameValueCollection and construct the complex type which is that of the Request which I can then supply to a nested instance of the original IWcfRequestProcessor  and work as it should normally.  To give an example of some of the urls which you I envisage with this method are: http://www.url.com/service.svc/json/process/getweather/?location=london http://www.url.com/service.svc/json/process/getproductsbycategory/?categoryid=1 http://www.url.om/service.svc/json/process/sayhello/?name=andy Another reason why my direction has gone to a single request for the REST implementation is because of restrictions which are imposed by browsers on the length of the url.  From what I have read this is on average 2000 characters.  I think that this is a very acceptable usage limit in the context of using 1 request, but I do not think this is acceptable for accommodating multiple requests chained together.  I would love to be corrected on that one, I really would but unfortunately from what I have read I have come to the conclusion that this is not the case. The mapping function So, as I say this is just the first pass I have made at this, and I am not overly happy with the try catch for detecting types without default constructors.  I know there is a better way but for the minute, it escapes me.  I would also like to know the correct way for adding mapping functions and not using the anonymous way that I have used.  To achieve this I have used recursion which I am sure is what other mapping function use. As you do have to go as deep as the complex type is. public static object RecurseType(NameValueCollection collection, Type type, string prefix) { try { var returnObject = Activator.CreateInstance(type); foreach (var property in type.GetProperties()) { foreach (var key in collection.AllKeys) { if (String.IsNullOrEmpty(prefix) || key.Length > prefix.Length) { var propertyNameToMatch = String.IsNullOrEmpty(prefix) ? key : key.Substring(property.Name.IndexOf(prefix) + prefix.Length + 1); if (property.Name == propertyNameToMatch) { property.SetValue(returnObject, Convert.ChangeType(collection.Get(key), property.PropertyType), null); } else if(property.GetValue(returnObject,null) == null) { property.SetValue(returnObject, RecurseType(collection, property.PropertyType, String.Concat(prefix, property.PropertyType.Name)), null); } } } } return returnObject; } catch (MissingMethodException) { //Quite a blunt way of dealing with Types without default constructor return null; } }   Another thing is performance, I have not measured this in anyway, it is as I say the first pass, so I hope this can be the start of a more perfected implementation.  I tested this out with a complex type of three levels, there is no intended logical meaning to the properties, they are simply for the purposes of example.  You could call this a spiking session, as from here on in, now I know what I am building I would take a more TDD approach.  OK, purists, why did I not do this from the start, well I didn’t, this was a brain dump and now I know what I am building I can. The console test and how I used with AutoMapper is as follows: static void Main(string[] args) { var collection = new NameValueCollection(); collection.Add("Name", "Andrew Rea"); collection.Add("Number", "1"); collection.Add("AddressLine1", "123 Street"); collection.Add("AddressNumber", "2"); collection.Add("AddressPostCodeCountry", "United Kingdom"); collection.Add("AddressPostCodeNumber", "3"); AutoMapper.Mapper.CreateMap<NameValueCollection, Person>() .ConvertUsing(x => { return(Person) RecurseType(x, typeof(Person), null); }); var person = AutoMapper.Mapper.Map<NameValueCollection, Person>(collection); Console.WriteLine(person.Name); Console.WriteLine(person.Number); Console.WriteLine(person.Address.Line1); Console.WriteLine(person.Address.Number); Console.WriteLine(person.Address.PostCode.Country); Console.WriteLine(person.Address.PostCode.Number); Console.ReadLine(); }   Notice the convention that I am using and that this method requires you do use.  Each property is prefixed with the constructed name of its parents combined.  This is the convention used by AutoMapper and it makes sense. I can also think of other uses for this including using with ASP.NET MVC ModelBinders for creating a complex type from the QueryString which is itself is a NameValueCollection. Hope this is of some help to people and I would welcome any code reviews you could give me. References: Agatha : http://code.google.com/p/agatha-rrsl/ AutoMapper : http://automapper.codeplex.com/   Cheers for now, Andrew   P.S. I will have the proposed solution for a more complete REST implementation for AGATHA very soon. 

    Read the article

  • ASP.NET MVC 3: Implicit and Explicit code nuggets with Razor

    - by ScottGu
    This is another in a series of posts I’m doing that cover some of the new ASP.NET MVC 3 features: New @model keyword in Razor (Oct 19th) Layouts with Razor (Oct 22nd) Server-Side Comments with Razor (Nov 12th) Razor’s @: and <text> syntax (Dec 15th) Implicit and Explicit code nuggets with Razor (today) In today’s post I’m going to discuss how Razor enables you to both implicitly and explicitly define code nuggets within your view templates, and walkthrough some code examples of each of them.  Fluid Coding with Razor ASP.NET MVC 3 ships with a new view-engine option called “Razor” (in addition to the existing .aspx view engine).  You can learn more about Razor, why we are introducing it, and the syntax it supports from my Introducing Razor blog post. Razor minimizes the number of characters and keystrokes required when writing a view template, and enables a fast, fluid coding workflow. Unlike most template syntaxes, you do not need to interrupt your coding to explicitly denote the start and end of server blocks within your HTML. The Razor parser is smart enough to infer this from your code. This enables a compact and expressive syntax which is clean, fast and fun to type. For example, the Razor snippet below can be used to iterate a collection of products and output a <ul> list of product names that link to their corresponding product pages: When run, the above code generates output like below: Notice above how we were able to embed two code nuggets within the content of the foreach loop.  One of them outputs the name of the Product, and the other embeds the ProductID within a hyperlink.  Notice that we didn’t have to explicitly wrap these code-nuggets - Razor was instead smart enough to implicitly identify where the code began and ended in both of these situations.  How Razor Enables Implicit Code Nuggets Razor does not define its own language.  Instead, the code you write within Razor code nuggets is standard C# or VB.  This allows you to re-use your existing language skills, and avoid having to learn a customized language grammar. The Razor parser has smarts built into it so that whenever possible you do not need to explicitly mark the end of C#/VB code nuggets you write.  This makes coding more fluid and productive, and enables a nice, clean, concise template syntax.  Below are a few scenarios that Razor supports where you can avoid having to explicitly mark the beginning/end of a code nugget, and instead have Razor implicitly identify the code nugget scope for you: Property Access Razor allows you to output a variable value, or a sub-property on a variable that is referenced via “dot” notation: You can also use “dot” notation to access sub-properties multiple levels deep: Array/Collection Indexing: Razor allows you to index into collections or arrays: Calling Methods: Razor also allows you to invoke methods: Notice how for all of the scenarios above how we did not have to explicitly end the code nugget.  Razor was able to implicitly identify the end of the code block for us. Razor’s Parsing Algorithm for Code Nuggets The below algorithm captures the core parsing logic we use to support “@” expressions within Razor, and to enable the implicit code nugget scenarios above: Parse an identifier - As soon as we see a character that isn't valid in a C# or VB identifier, we stop and move to step 2 Check for brackets - If we see "(" or "[", go to step 2.1., otherwise, go to step 3  Parse until the matching ")" or "]" (we track nested "()" and "[]" pairs and ignore "()[]" we see in strings or comments) Go back to step 2 Check for a "." - If we see one, go to step 3.1, otherwise, DO NOT ACCEPT THE "." as code, and go to step 4 If the character AFTER the "." is a valid identifier, accept the "." and go back to step 1, otherwise, go to step 4 Done! Differentiating between code and content Step 3.1 is a particularly interesting part of the above algorithm, and enables Razor to differentiate between scenarios where an identifier is being used as part of the code statement, and when it should instead be treated as static content: Notice how in the snippet above we have ? and ! characters at the end of our code nuggets.  These are both legal C# identifiers – but Razor is able to implicitly identify that they should be treated as static string content as opposed to being part of the code expression because there is whitespace after them.  This is pretty cool and saves us keystrokes. Explicit Code Nuggets in Razor Razor is smart enough to implicitly identify a lot of code nugget scenarios.  But there are still times when you want/need to be more explicit in how you scope the code nugget expression.  The @(expression) syntax allows you to do this: You can write any C#/VB code statement you want within the @() syntax.  Razor will treat the wrapping () characters as the explicit scope of the code nugget statement.  Below are a few scenarios where we could use the explicit code nugget feature: Perform Arithmetic Calculation/Modification: You can perform arithmetic calculations within an explicit code nugget: Appending Text to a Code Expression Result: You can use the explicit expression syntax to append static text at the end of a code nugget without having to worry about it being incorrectly parsed as code: Above we have embedded a code nugget within an <img> element’s src attribute.  It allows us to link to images with URLs like “/Images/Beverages.jpg”.  Without the explicit parenthesis, Razor would have looked for a “.jpg” property on the CategoryName (and raised an error).  By being explicit we can clearly denote where the code ends and the text begins. Using Generics and Lambdas Explicit expressions also allow us to use generic types and generic methods within code expressions – and enable us to avoid the <> characters in generics from being ambiguous with tag elements. One More Thing….Intellisense within Attributes We have used code nuggets within HTML attributes in several of the examples above.  One nice feature supported by the Razor code editor within Visual Studio is the ability to still get VB/C# intellisense when doing this. Below is an example of C# code intellisense when using an implicit code nugget within an <a> href=”” attribute: Below is an example of C# code intellisense when using an explicit code nugget embedded in the middle of a <img> src=”” attribute: Notice how we are getting full code intellisense for both scenarios – despite the fact that the code expression is embedded within an HTML attribute (something the existing .aspx code editor doesn’t support).  This makes writing code even easier, and ensures that you can take advantage of intellisense everywhere. Summary Razor enables a clean and concise templating syntax that enables a very fluid coding workflow.  Razor’s ability to implicitly scope code nuggets reduces the amount of typing you need to perform, and leaves you with really clean code. When necessary, you can also explicitly scope code expressions using a @(expression) syntax to provide greater clarity around your intent, as well as to disambiguate code statements from static markup. Hope this helps, Scott P.S. In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu

    Read the article

  • BNF – how to read syntax?

    - by Piotr Rodak
    A few days ago I read post of Jen McCown (blog) about her idea of blogging about random articles from Books Online. I think this is a great idea, even if Jen says that it’s not exciting or sexy. I noticed that many of the questions that appear on forums and other media arise from pure fact that people asking questions didn’t bother to read and understand the manual – Books Online. Jen came up with a brilliant, concise acronym that describes very well the category of posts about Books Online – RTFM365. I take liberty of tagging this post with the same acronym. I often come across questions of type – ‘Hey, i am trying to create a table, but I am getting an error’. The error often says that the syntax is invalid. 1 CREATE TABLE dbo.Employees 2 (guid uniqueidentifier CONSTRAINT DEFAULT Guid_Default NEWSEQUENTIALID() ROWGUIDCOL, 3 Employee_Name varchar(60) 4 CONSTRAINT Guid_PK PRIMARY KEY (guid) ); 5 The answer is usually(1), ‘Ok, let me check it out.. Ah yes – you have to put name of the DEFAULT constraint before the type of constraint: 1 CREATE TABLE dbo.Employees 2 (guid uniqueidentifier CONSTRAINT Guid_Default DEFAULT NEWSEQUENTIALID() ROWGUIDCOL, 3 Employee_Name varchar(60) 4 CONSTRAINT Guid_PK PRIMARY KEY (guid) ); Why many people stumble on syntax errors? Is the syntax poorly documented? No, the issue is, that correct syntax of the CREATE TABLE statement is documented very well in Books Online and is.. intimidating. Many people can be taken aback by the rather complex block of code that describes all intricacies of the statement. However, I don’t know better way of defining syntax of the statement or command. The notation that is used to describe syntax in Books Online is a form of Backus-Naur notatiion, called BNF for short sometimes. This is a notation that was invented around 50 years ago, and some say that even earlier, around 400 BC – would you believe? Originally it was used to define syntax of, rather ancient now, ALGOL programming language (in 1950’s, not in ancient India). If you look closer at the definition of the BNF, it turns out that the principles of this syntax are pretty simple. Here are a few bullet points: italic_text is a placeholder for your identifier <italic_text_in_angle_brackets> is a definition which is described further. [everything in square brackets] is optional {everything in curly brackets} is obligatory everything | separated | by | operator is an alternative ::= “assigns” definition to an identifier Yes, it looks like these six simple points give you the key to understand even the most complicated syntax definitions in Books Online. Books Online contain an article about syntax conventions – have you ever read it? Let’s have a look at fragment of the CREATE TABLE statement: 1 CREATE TABLE 2 [ database_name . [ schema_name ] . | schema_name . ] table_name 3 ( { <column_definition> | <computed_column_definition> 4 | <column_set_definition> } 5 [ <table_constraint> ] [ ,...n ] ) 6 [ ON { partition_scheme_name ( partition_column_name ) | filegroup 7 | "default" } ] 8 [ { TEXTIMAGE_ON { filegroup | "default" } ] 9 [ FILESTREAM_ON { partition_scheme_name | filegroup 10 | "default" } ] 11 [ WITH ( <table_option> [ ,...n ] ) ] 12 [ ; ] Let’s look at line 2 of the above snippet: This line uses rules 3 and 5 from the list. So you know that you can create table which has specified one of the following. just name – table will be created in default user schema schema name and table name – table will be created in specified schema database name, schema name and table name – table will be created in specified database, in specified schema database name, .., table name – table will be created in specified database, in default schema of the user. Note that this single line of the notation describes each of the naming schemes in deterministic way. The ‘optionality’ of the schema_name element is nested within database_name.. section. You can use either database_name and optional schema name, or just schema name – this is specified by the pipe character ‘|’. The error that user gets with execution of the first script fragment in this post is as follows: Msg 156, Level 15, State 1, Line 2 Incorrect syntax near the keyword 'DEFAULT'. Ok, let’s have a look how to find out the correct syntax. Line number 3 of the BNF fragment above contains reference to <column_definition>. Since column_definition is in angle brackets, we know that this is a reference to notion described further in the code. And indeed, the very next fragment of BNF contains syntax of the column definition. 1 <column_definition> ::= 2 column_name <data_type> 3 [ FILESTREAM ] 4 [ COLLATE collation_name ] 5 [ NULL | NOT NULL ] 6 [ 7 [ CONSTRAINT constraint_name ] DEFAULT constant_expression ] 8 | [ IDENTITY [ ( seed ,increment ) ] [ NOT FOR REPLICATION ] 9 ] 10 [ ROWGUIDCOL ] [ <column_constraint> [ ...n ] ] 11 [ SPARSE ] Look at line 7 in the above fragment. It says, that the column can have a DEFAULT constraint which, if you want to name it, has to be prepended with [CONSTRAINT constraint_name] sequence. The name of the constraint is optional, but I strongly recommend you to make the effort of coming up with some meaningful name yourself. So the correct syntax of the CREATE TABLE statement from the beginning of the article is like this: 1 CREATE TABLE dbo.Employees 2 (guid uniqueidentifier CONSTRAINT Guid_Default DEFAULT NEWSEQUENTIALID() ROWGUIDCOL, 3 Employee_Name varchar(60) 4 CONSTRAINT Guid_PK PRIMARY KEY (guid) ); That is practically everything you should know about BNF. I encourage you to study the syntax definitions for various statements and commands in Books Online, you can find really interesting things hidden there. Technorati Tags: SQL Server,t-sql,BNF,syntax   (1) No, my answer usually is a question – ‘What error message? What does it say?’. You’d be surprised to know how many people think I can go through time and space and look at their screen at the moment they received the error.

    Read the article

  • A Guided Tour of Complexity

    - by JoshReuben
    I just re-read Complexity – A Guided Tour by Melanie Mitchell , protégé of Douglas Hofstadter ( author of “Gödel, Escher, Bach”) http://www.amazon.com/Complexity-Guided-Tour-Melanie-Mitchell/dp/0199798109/ref=sr_1_1?ie=UTF8&qid=1339744329&sr=8-1 here are some notes and links:   Evolved from Cybernetics, General Systems Theory, Synergetics some interesting transdisciplinary fields to investigate: Chaos Theory - http://en.wikipedia.org/wiki/Chaos_theory – small differences in initial conditions (such as those due to rounding errors in numerical computation) yield widely diverging outcomes for chaotic systems, rendering long-term prediction impossible. System Dynamics / Cybernetics - http://en.wikipedia.org/wiki/System_Dynamics – study of how feedback changes system behavior Network Theory - http://en.wikipedia.org/wiki/Network_theory – leverage Graph Theory to analyze symmetric  / asymmetric relations between discrete objects Algebraic Topology - http://en.wikipedia.org/wiki/Algebraic_topology – leverage abstract algebra to analyze topological spaces There are limits to deterministic systems & to computation. Chaos Theory definitely applies to training an ANN (artificial neural network) – different weights will emerge depending upon the random selection of the training set. In recursive Non-Linear systems http://en.wikipedia.org/wiki/Nonlinear_system – output is not directly inferable from input. E.g. a Logistic map: Xt+1 = R Xt(1-Xt) Different types of bifurcations, attractor states and oscillations may occur – e.g. a Lorenz Attractor http://en.wikipedia.org/wiki/Lorenz_system Feigenbaum Constants http://en.wikipedia.org/wiki/Feigenbaum_constants express ratios in a bifurcation diagram for a non-linear map – the convergent limit of R (the rate of period-doubling bifurcations) is 4.6692016 Maxwell’s Demon - http://en.wikipedia.org/wiki/Maxwell%27s_demon - the Second Law of Thermodynamics has only a statistical certainty – the universe (and thus information) tends towards entropy. While any computation can theoretically be done without expending energy, with finite memory, the act of erasing memory is permanent and increases entropy. Life & thought is a counter-example to the universe’s tendency towards entropy. Leo Szilard and later Claude Shannon came up with the Information Theory of Entropy - http://en.wikipedia.org/wiki/Entropy_(information_theory) whereby Shannon entropy quantifies the expected value of a message’s information in bits in order to determine channel capacity and leverage Coding Theory (compression analysis). Ludwig Boltzmann came up with Statistical Mechanics - http://en.wikipedia.org/wiki/Statistical_mechanics – whereby our Newtonian perception of continuous reality is a probabilistic and statistical aggregate of many discrete quantum microstates. This is relevant for Quantum Information Theory http://en.wikipedia.org/wiki/Quantum_information and the Physics of Information - http://en.wikipedia.org/wiki/Physical_information. Hilbert’s Problems http://en.wikipedia.org/wiki/Hilbert's_problems pondered whether mathematics is complete, consistent, and decidable (the Decision Problem – http://en.wikipedia.org/wiki/Entscheidungsproblem – is there always an algorithm that can determine whether a statement is true).  Godel’s Incompleteness Theorems http://en.wikipedia.org/wiki/G%C3%B6del's_incompleteness_theorems  proved that mathematics cannot be both complete and consistent (e.g. “This statement is not provable”). Turing through the use of Turing Machines (http://en.wikipedia.org/wiki/Turing_machine symbol processors that can prove mathematical statements) and Universal Turing Machines (http://en.wikipedia.org/wiki/Universal_Turing_machine Turing Machines that can emulate other any Turing Machine via accepting programs as well as data as input symbols) that computation is limited by demonstrating the Halting Problem http://en.wikipedia.org/wiki/Halting_problem (is is not possible to know when a program will complete – you cannot build an infinite loop detector). You may be used to thinking of 1 / 2 / 3 dimensional systems, but Fractal http://en.wikipedia.org/wiki/Fractal systems are defined by self-similarity & have non-integer Hausdorff Dimensions !!!  http://en.wikipedia.org/wiki/List_of_fractals_by_Hausdorff_dimension – the fractal dimension quantifies the number of copies of a self similar object at each level of detail – eg Koch Snowflake - http://en.wikipedia.org/wiki/Koch_snowflake Definitions of complexity: size, Shannon entropy, Algorithmic Information Content (http://en.wikipedia.org/wiki/Algorithmic_information_theory - size of shortest program that can generate a description of an object) Logical depth (amount of info processed), thermodynamic depth (resources required). Complexity is statistical and fractal. John Von Neumann’s other machine was the Self-Reproducing Automaton http://en.wikipedia.org/wiki/Self-replicating_machine  . Cellular Automata http://en.wikipedia.org/wiki/Cellular_automaton are alternative form of Universal Turing machine to traditional Von Neumann machines where grid cells are locally synchronized with their neighbors according to a rule. Conway’s Game of Life http://en.wikipedia.org/wiki/Conway's_Game_of_Life demonstrates various emergent constructs such as “Glider Guns” and “Spaceships”. Cellular Automatons are not practical because logical ops require a large number of cells – wasteful & inefficient. There are no compilers or general program languages available for Cellular Automatons (as far as I am aware). Random Boolean Networks http://en.wikipedia.org/wiki/Boolean_network are extensions of cellular automata where nodes are connected at random (not to spatial neighbors) and each node has its own rule –> they demonstrate the emergence of complex  & self organized behavior. Stephen Wolfram’s (creator of Mathematica, so give him the benefit of the doubt) New Kind of Science http://en.wikipedia.org/wiki/A_New_Kind_of_Science proposes the universe may be a discrete Finite State Automata http://en.wikipedia.org/wiki/Finite-state_machine whereby reality emerges from simple rules. I am 2/3 through this book. It is feasible that the universe is quantum discrete at the plank scale and that it computes itself – Digital Physics: http://en.wikipedia.org/wiki/Digital_physics – a simulated reality? Anyway, all behavior is supposedly derived from simple algorithmic rules & falls into 4 patterns: uniform , nested / cyclical, random (Rule 30 http://en.wikipedia.org/wiki/Rule_30) & mixed (Rule 110 - http://en.wikipedia.org/wiki/Rule_110 localized structures – it is this that is interesting). interaction between colliding propagating signal inputs is then information processing. Wolfram proposes the Principle of Computational Equivalence - http://mathworld.wolfram.com/PrincipleofComputationalEquivalence.html - all processes that are not obviously simple can be viewed as computations of equivalent sophistication. Meaning in information may emerge from analogy & conceptual slippages – see the CopyCat program: http://cognitrn.psych.indiana.edu/rgoldsto/courses/concepts/copycat.pdf Scale Free Networks http://en.wikipedia.org/wiki/Scale-free_network have a distribution governed by a Power Law (http://en.wikipedia.org/wiki/Power_law - much more common than Normal Distribution). They are characterized by hubs (resilience to random deletion of nodes), heterogeneity of degree values, self similarity, & small world structure. They grow via preferential attachment http://en.wikipedia.org/wiki/Preferential_attachment – tipping points triggered by positive feedback loops. 2 theories of cascading system failures in complex systems are Self-Organized Criticality http://en.wikipedia.org/wiki/Self-organized_criticality and Highly Optimized Tolerance http://en.wikipedia.org/wiki/Highly_optimized_tolerance. Computational Mechanics http://en.wikipedia.org/wiki/Computational_mechanics – use of computational methods to study phenomena governed by the principles of mechanics. This book is a great intuition pump, but does not cover the more mathematical subject of Computational Complexity Theory – http://en.wikipedia.org/wiki/Computational_complexity_theory I am currently reading this book on this subject: http://www.amazon.com/Computational-Complexity-Christos-H-Papadimitriou/dp/0201530821/ref=pd_sim_b_1   stay tuned for that review!

    Read the article

  • CodePlex Daily Summary for Thursday, March 11, 2010

    CodePlex Daily Summary for Thursday, March 11, 2010New ProjectsASP.NET Wiki Control: This ASP.NET user control allows you to embed a very useful wiki directly into your already existing ASP.NET website taking advantage of the popula...BabyLog: Log baby daily activity.buddyHome: buddyHome is a project that can make your home smarter. as good as your buddy. Cloud Community: Cloud Community makes it easier for organizations to have a simple to use community platform. Our mission is to create an easy to use community pl...Community Connectors for Microsoft CRM 4.0: Community Connectors for Microsoft CRM 4.0 allows Microsoft CRM 4.0 customers and partners to monitor and analyze customers’ interaction from their...Console Highlighter: Hightlights Microsoft Windows Command prompt (cmd.exe) by outputting ANSI VT100 Control sequences to color the output. These sequences are not hand...Cornell Store: This is IN NO WAY officially affiliated or related to the Cornell University store. Instead, this is a project that I am doing for a class. Ther...DevUtilities: This project is for creating some utility tools, and they will be useful during the development.DotNetNuke® Skin Maple: A DotNetNuke Design Challenge skin package submitted to the "Personal" category by DyNNamite.co.uk. The package includes 4 color variations and sev...HRNet: HRNetIIS Web Site Monitoring: A software for monitor a particular web site on IIS, even if its IP is sharing between different web site.Iowa Code Camp: The source code for the Iowa Code Camp website.Leonidas: Leonidas is a virtual tutorLunch 'n Learn: The Lunch 'n Learn web application is an open source ASP.NET MVC application that allows you to setup lunch 'n learn presentations for your team, c...MNT Cryptography: A very simple cryptography classMooiNooi MVC2LINQ2SQL Web Databinder: mvc2linq2sql is a databinder for ASP.NET MVC that make able developer to clean bind object from HTML FORMS to Linq entities. Even 1 to N relations ...MoqBot: MoqBot is an auto mocking library for Moq and Ninject.mtExperience1: hoiMvcPager: MvcPager is a free paging component for ASP.NET MVC web application, it exposes a series of extension methods for using in ASP.NET MVC applications...OCal: OCal is based on object calisthenics to identify code smellsPex Custom Arithmetic Solver: Pex Custom Arithmetic Solver contains a collection of meta-heuristic search algorithms. The goal is to improve Pex's code coverage for code involvi...SetControls: Расширеные контролы для ASP.NET приложений. Полная информация ближе к релизу...shadowrage1597: CTC 195 Game Design classSharePoint Team-Mailer: A SharePoint 2007 solution that defines a generic CustomList for sending e-mails to SharePoint Groups.Sql Share: SQL Share is a collaboration tool used within the science to allow database engineers to work tightly with domain scientists.TechCalendar: Tech Events Calendar ASP.NET project.ZLYScript: A very simple script language compiler.New ReleasesALGLIB: ALGLIB 2.4.0: New ALGLIB release contains: improved versions of several linear algebra algorithms: QR decomposition, matrix inversion, condition number estimatio...AmiBroker Plug-Ins with C#: AmiBroker Plug-Ins v0.0.2: Source codes and a binaryAppFabric Caching UI Admin Tool: AppFabric Caching Beta 2 UI Admin Tool: System Requirements:.NET 4.0 RC AppFabric Caching Beta2 Test On:Win 7 (64x)Autodocs - WCF REST Automatic API Documentation Generator: Autodocs.ServiceModel.Web: This archive contains the reference DLL, instructions and license.Compact Plugs & Compact Injection: Compact Injection and Compact Plugs 1.1 Beta: First release of Compact Plugs (CP). The solution includes a simple example project of CP, called "TestCompactPlugs1". Also some fixes where made ...Console Highlighter: Console Highlighter 0.9 (preview release): Preliminary release.Encrypted Notes: Encrypted Notes 1.3: This is the latest version of Encrypted Notes (1.3). It has an installer - it will create a directory 'CPascoe' in My Documents. The last one was ...Family Tree Analyzer: Version 1.0.2: Family Tree Analyzer Version 1.0.2 This early beta version implements loading a gedcom file and displaying some basic reports. These reports inclu...FRC1103 - FRC Dashboard viewer: 2010 Documentation v0.1: This is my current version of the control system documentation for 2010. It isn't complete, but it has the information required for a custom dashbo...jQuery.cssLess: jQuery.cssLess 0.5 (Even less release): NEW - support for nested special CSS classes (like :hover) MAIN RELEASE This release, code "Even less", is the one that will interpret cssLess wit...MooiNooi MVC2LINQ2SQL Web Databinder: MooiNooi MVC2LINQ2SQL DataBinder: I didn't try this... I just took it off from my project. Please, tell me any problem implementing in your own development and I'll be pleased to h...MvcPager: MvcPager 1.2 for ASP.NET MVC 1.0: MvcPager 1.2 for ASP.NET MVC 1.0Mytrip.Mvc: Mytrip 1.0 preview 1: Article Manager Blog Manager L2S Membership(.NET Framework 3.5) EF Membership(.NET Framework 4) User Manager File Manager Localization Captcha ...NodeXL: Network Overview, Discovery and Exploration for Excel: NodeXL Excel 2007 Template, version 1.0.1.117: The NodeXL Excel 2007 template displays a network graph using edge and vertex lists stored in an Excel 2007 workbook. What's NewThis version adds ...Pex Custom Arithmetic Solver: PexCustomArithmeticSolver: This is the alpha release containing the Alternating Variable Method and Evolution Strategies to try and solve constraints over floating point vari...Scrum Sprint Monitor: v1.0.0.44877: What is new in this release? Major performance increase in animations (up to 50 fps from 2 fps) by replacing DropShadow effect with png bitmaps; ...sELedit: sELedit v1.0b: + Added support for empty strings / wstrings + Fixed: critical bug in configuration files (list 53)sPWadmin: pwAdmin v0.9_nightly: + Fixed: XML editor can now open and save character templates + Added: PWI item name database + Added: Plugin SupportTechCalendar: Events Calendar v.1.0: Initial release.The Silverlight Hyper Video Player [http://slhvp.com]: Beta 2: Beta 2.0 Some fixes from Beta 1, and a couple small enhancements. Intensive testing continues, and I will continue to update the code at least ever...ThreadSafe.Caching: 2010.03.10.1: Updates to the scavanging behaviour since last release. Scavenging will now occur every 30 seconds by default and all objects in the cache will be ...VCC: Latest build, v2.1.30310.0: Automatic drop of latest buildVisual Studio DSite: Email Sender (C++): The same Email Sender program that I but made in visual c plus plus 2008 instead of visual basic 2008.Web Forms MVP: Web Forms MVP CTP7: The release can be considered stable, and is in use behind several high traffic, public websites. It has been marked as a CTP release as it is not ...White Tiger: 0.0.3.1: Now you can load or create files with whatever root element you want *check f or sets file permisionsMost Popular ProjectsMetaSharpWBFS ManagerRawrAJAX Control ToolkitMicrosoft SQL Server Product Samples: DatabaseSilverlight ToolkitWindows Presentation Foundation (WPF)ASP.NETMicrosoft SQL Server Community & SamplesASP.NET Ajax LibraryMost Active ProjectsUmbraco CMSRawrSDS: Scientific DataSet library and toolsN2 CMSFasterflect - A Fast and Simple Reflection APIjQuery Library for SharePoint Web ServicesBlogEngine.NETFarseer Physics Enginepatterns & practices – Enterprise LibraryCaliburn: An Application Framework for WPF and Silverlight

    Read the article

  • Using a "white list" for extracting terms for Text Mining

    - by [email protected]
    In Part 1 of my post on "Generating cluster names from a document clustering model" (part 1, part 2, part 3), I showed how to build a clustering model from text documents using Oracle Data Miner, which automates preparing data for text mining. In this process we specified a custom stoplist and lexer and relied on Oracle Text to identify important terms.  However, there is an alternative approach, the white list, which uses a thesaurus object with the Oracle Text CTXRULE index to allow you to specify the important terms. INTRODUCTIONA stoplist is used to exclude, i.e., black list, specific words in your documents from being indexed. For example, words like a, if, and, or, and but normally add no value when text mining. Other words can also be excluded if they do not help to differentiate documents, e.g., the word Oracle is ubiquitous in the Oracle product literature. One problem with stoplists is determining which words to specify. This usually requires inspecting the terms that are extracted, manually identifying which ones you don't want, and then re-indexing the documents to determine if you missed any. Since a corpus of documents could contain thousands of words, this could be a tedious exercise. Moreover, since every word is considered as an individual token, a term excluded in one context may be needed to help identify a term in another context. For example, in our Oracle product literature example, the words "Oracle Data Mining" taken individually are not particular helpful. The term "Oracle" may be found in nearly all documents, as with the term "Data." The term "Mining" is more unique, but could also refer to the Mining industry. If we exclude "Oracle" and "Data" by specifying them in the stoplist, we lose valuable information. But it we include them, they may introduce too much noise. Still, when you have a broad vocabulary or don't have a list of specific terms of interest, you rely on the text engine to identify important terms, often by computing the term frequency - inverse document frequency metric. (This is effectively a weight associated with each term indicating its relative importance in a document within a collection of documents. We'll revisit this later.) The results using this technique is often quite valuable. As noted above, an alternative to the subtractive nature of the stoplist is to specify a white list, or a list of terms--perhaps multi-word--that we want to extract and use for data mining. The obvious downside to this approach is the need to specify the set of terms of interest. However, this may not be as daunting a task as it seems. For example, in a given domain (Oracle product literature), there is often a recognized glossary, or a list of keywords and phrases (Oracle product names, industry names, product categories, etc.). Being able to identify multi-word terms, e.g., "Oracle Data Mining" or "Customer Relationship Management" as a single token can greatly increase the quality of the data mining results. The remainder of this post and subsequent posts will focus on how to produce a dataset that contains white list terms, suitable for mining. CREATING A WHITE LIST We'll leverage the thesaurus capability of Oracle Text. Using a thesaurus, we create a set of rules that are in effect our mapping from single and multi-word terms to the tokens used to represent those terms. For example, "Oracle Data Mining" becomes "ORACLEDATAMINING." First, we'll create and populate a mapping table called my_term_token_map. All text has been converted to upper case and values in the TERM column are intended to be mapped to the token in the TOKEN column. TERM                                TOKEN DATA MINING                         DATAMINING ORACLE DATA MINING                  ORACLEDATAMINING 11G                                 ORACLE11G JAVA                                JAVA CRM                                 CRM CUSTOMER RELATIONSHIP MANAGEMENT    CRM ... Next, we'll create a thesaurus object my_thesaurus and a rules table my_thesaurus_rules: CTX_THES.CREATE_THESAURUS('my_thesaurus', FALSE); CREATE TABLE my_thesaurus_rules (main_term     VARCHAR2(100),                                  query_string  VARCHAR2(400)); We next populate the thesaurus object and rules table using the term token map. A cursor is defined over my_term_token_map. As we iterate over  the rows, we insert a synonym relationship 'SYN' into the thesaurus. We also insert into the table my_thesaurus_rules the main term, and the corresponding query string, which specifies synonyms for the token in the thesaurus. DECLARE   cursor c2 is     select token, term     from my_term_token_map; BEGIN   for r_c2 in c2 loop     CTX_THES.CREATE_RELATION('my_thesaurus',r_c2.token,'SYN',r_c2.term);     EXECUTE IMMEDIATE 'insert into my_thesaurus_rules values                        (:1,''SYN(' || r_c2.token || ', my_thesaurus)'')'     using r_c2.token;   end loop; END; We are effectively inserting the token to return and the corresponding query that will look up synonyms in our thesaurus into the my_thesaurus_rules table, for example:     'ORACLEDATAMINING'        SYN ('ORACLEDATAMINING', my_thesaurus)At this point, we create a CTXRULE index on the my_thesaurus_rules table: create index my_thesaurus_rules_idx on        my_thesaurus_rules(query_string)        indextype is ctxsys.ctxrule; In my next post, this index will be used to extract the tokens that match each of the rules specified. We'll then compute the tf-idf weights for each of the terms and create a nested table suitable for mining.

    Read the article

  • Dynamically creating a Generic Type at Runtime

    - by Rick Strahl
    I learned something new today. Not uncommon, but it's a core .NET runtime feature I simply did not know although I know I've run into this issue a few times and worked around it in other ways. Today there was no working around it and a few folks on Twitter pointed me in the right direction. The question I ran into is: How do I create a type instance of a generic type when I have dynamically acquired the type at runtime? Yup it's not something that you do everyday, but when you're writing code that parses objects dynamically at runtime it comes up from time to time. In my case it's in the bowels of a custom JSON parser. After some thought triggered by a comment today I realized it would be fairly easy to implement two-way Dictionary parsing for most concrete dictionary types. I could use a custom Dictionary serialization format that serializes as an array of key/value objects. Basically I can use a custom type (that matches the JSON signature) to hold my parsed dictionary data and then add it to the actual dictionary when parsing is complete. Generic Types at Runtime One issue that came up in the process was how to figure out what type the Dictionary<K,V> generic parameters take. Reflection actually makes it fairly easy to figure out generic types at runtime with code like this: if (arrayType.GetInterface("IDictionary") != null) { if (arrayType.IsGenericType) { var keyType = arrayType.GetGenericArguments()[0]; var valueType = arrayType.GetGenericArguments()[1]; … } } The GetArrayType method gets passed a type instance that is the array or array-like object that is rendered in JSON as an array (which includes IList, IDictionary, IDataReader and a few others). In my case the type passed would be something like Dictionary<string, CustomerEntity>. So I know what the parent container class type is. Based on the the container type using it's then possible to use GetGenericTypeArguments() to retrieve all the generic types in sequential order of definition (ie. string, CustomerEntity). That's the easy part. Creating a Generic Type and Providing Generic Parameters at RunTime The next problem is how do I get a concrete type instance for the generic type? I know what the type name and I have a type instance is but it's generic, so how do I get a type reference to keyvaluepair<K,V> that is specific to the keyType and valueType above? Here are a couple of things that come to mind but that don't work (and yes I tried that unsuccessfully first): Type elementType = typeof(keyvalue<keyType, valueType>); Type elementType = typeof(keyvalue<typeof(keyType), typeof(valueType)>); The problem is that this explicit syntax expects a type literal not some dynamic runtime value, so both of the above won't even compile. I turns out the way to create a generic type at runtime is using a fancy bit of syntax that until today I was completely unaware of: Type elementType = typeof(keyvalue<,>).MakeGenericType(keyType, valueType); The key is the type(keyvalue<,>) bit which looks weird at best. It works however and produces a non-generic type reference. You can see the difference between the full generic type and the non-typed (?) generic type in the debugger: The nonGenericType doesn't show any type specialization, while the elementType type shows the string, CustomerEntity (truncated above) in the type name. Once the full type reference exists (elementType) it's then easy to create an instance. In my case the parser parses through the JSON and when it completes parsing the value/object it creates a new keyvalue<T,V> instance. Now that I know the element type that's pretty trivial with: // Objects start out null until we find the opening tag resultObject = Activator.CreateInstance(elementType); Here the result object is picked up by the JSON array parser which creates an instance of the child object (keyvalue<K,V>) and then parses and assigns values from the JSON document using the types  key/value property signature. Internally the parser then takes each individually parsed item and adds it to a list of  List<keyvalue<K,V>> items. Parsing through a Generic type when you only have Runtime Type Information When parsing of the JSON array is done, the List needs to be turned into a defacto Dictionary<K,V>. This should be easy since I know that I'm dealing with an IDictionary, and I know the generic types for the key and value. The problem is again though that this needs to happen at runtime which would mean using several Convert.ChangeType() calls in the code to dynamically cast at runtime. Yuk. In the end I decided the easier and probably only slightly slower way to do this is a to use the dynamic type to collect the items and assign them to avoid all the dynamic casting madness: else if (IsIDictionary) { IDictionary dict = Activator.CreateInstance(arrayType) as IDictionary; foreach (dynamic item in items) { dict.Add(item.key, item.value); } return dict; } This code creates an instance of the generic dictionary type first, then loops through all of my custom keyvalue<K,V> items and assigns them to the actual dictionary. By using Dynamic here I can side step all the explicit type conversions that would be required in the three highlighted areas (not to mention that this nested method doesn't have access to the dictionary item generic types here). Static <- -> Dynamic Dynamic casting in a static language like C# is a bitch to say the least. This is one of the few times when I've cursed static typing and the arcane syntax that's required to coax types into the right format. It works but it's pretty nasty code. If it weren't for dynamic that last bit of code would have been a pretty ugly as well with a bunch of Convert.ChangeType() calls to litter the code. Fortunately this type of type convulsion is rather rare and reserved for system level code. It's not every day that you create a string to object parser after all :-)© Rick Strahl, West Wind Technologies, 2005-2011Posted in .NET  CSharp   Tweet (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

    Read the article

< Previous Page | 90 91 92 93 94 95 96 97 98 99 100 101  | Next Page >