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  • Find the occurrence of word/character in SQL column with wildcard character - PATINDEX

    - by Vipin
    CharIndex and PatIndex both can be used to determine the presence of character or string within sql column data. Both returns the starting position of the first occurrence of the character/word within expression. However, one major difference between CharIndex and PatIndex is that later allows the use of wild card characters while searching for character or word within column data. Also, Patindex is useful for searching within Text datatype. Allowed wild card characters are % and _ . " % "  - use it for any number of characters " _ "  - use it for a single character. Syntax PATINDEX('%pattern%', string_expression) Note - it's mandatory to include pattern within %% characters. returns starting position of occurrence of pattern, if found. returns 0, if not found returns NULL , if either pattern or string_expression is null. Example SELECT fldname FROM tblUsers WHERE PatIndex('%v_pin%', fldname) > 0

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  • How to avoid big and clumpsy UITableViewController on iOS?

    - by Johan Karlsson
    I have a problem when implementing the MVC-pattern on iOS. I have searched the Internet but seems not to find any nice solution to this problem. Many UITableViewController implementations seems to be rather big. Most example I have seen lets the UITableViewController implement UITableViewDelegate and UITableViewDataSource. These implementations are a big reason why UITableViewControlleris getting big. One solution would be to create separate classes that implements UITableViewDelegate and UITableViewDataSource. Of course these classes would have to have a reference to the UITableViewController. Are there any drawbacks using this solution? In general I think you should delegate the functionality to other "Helper" classes or similar, using the delegate pattern. Are there any well established ways of solving this problem? I do not want the model to contain to much functionality, nor the view. A believe that the logic should really be in the controller class, since this is one of the cornerstones of the MVC-pattern. But the big question is; How should you divide the controller of a MVC-implementation into smaller manageable pieces? (Applies to MVC in iOS in this case) There might be a general pattern for solving this, although I am specifically looking for a solution for iOS. Please give an example of a good pattern for solving this issue. Also an argument why this solution is awesome.

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  • How to avoid big and clumsy UITableViewController on iOS?

    - by Johan Karlsson
    I have a problem when implementing the MVC-pattern on iOS. I have searched the Internet but seems not to find any nice solution to this problem. Many UITableViewController implementations seems to be rather big. Most examples I have seen lets the UITableViewController implement <UITableViewDelegate> and <UITableViewDataSource>. These implementations are a big reason why UITableViewControlleris getting big. One solution would be to create separate classes that implements <UITableViewDelegate> and <UITableViewDataSource>. Of course these classes would have to have a reference to the UITableViewController. Are there any drawbacks using this solution? In general I think you should delegate the functionality to other "Helper" classes or similar, using the delegate pattern. Are there any well established ways of solving this problem? I do not want the model to contain too much functionality, nor the view. I believe that the logic should really be in the controller class, since this is one of the cornerstones of the MVC-pattern. But the big question is: How should you divide the controller of a MVC-implementation into smaller manageable pieces? (Applies to MVC in iOS in this case) There might be a general pattern for solving this, although I am specifically looking for a solution for iOS. Please give an example of a good pattern for solving this issue. Please provide an argument why your solution is awesome.

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  • Design Patterns - Why the need for interfaces?

    - by Kyle Johnson
    OK. I am learning design patterns. Every time I see someone code an example of a design pattern they use interfaces. Here is an example: http://visualstudiomagazine.com/Articles/2013/06/18/the-facade-pattern-in-net.aspx?Page=1 Can someone explain to me why was the interfaces needed in this example to demonstrate the facade pattern? The program work if you pass in the classes to the facade instead of the interface. If I don't have interfaces does that mean

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  • Game AI: Pattern for implementing Sense-Think-Act components?

    - by Rosarch
    I'm developing a game. Each entity in the game is a GameObject. Each GameObject is composed of a GameObjectController, GameObjectModel, and GameObjectView. (Or inheritants thereof.) For NPCs, the GameObjectController is split into: IThinkNPC: reads current state and makes a decision about what to do IActNPC: updates state based on what needs to be done ISenseNPC: reads current state to answer world queries (eg "am I being in the shadows?") My question: Is this ok for the ISenseNPC interface? public interface ISenseNPC { // ... /// <summary> /// True if `dest` is a safe point to which to retreat. /// </summary> /// <param name="dest"></param> /// <param name="angleToThreat"></param> /// <param name="range"></param> /// <returns></returns> bool IsSafeToRetreat(Vector2 dest, float angleToThreat, float range); /// <summary> /// Finds a new location to which to retreat. /// </summary> /// <param name="angleToThreat"></param> /// <returns></returns> Vector2 newRetreatDest(float angleToThreat); /// <summary> /// Returns the closest LightSource that illuminates the NPC. /// Null if the NPC is not illuminated. /// </summary> /// <returns></returns> ILightSource ClosestIlluminatingLight(); /// <summary> /// True if the NPC is sufficiently far away from target. /// Assumes that target is the only entity it could ever run from. /// </summary> /// <returns></returns> bool IsSafeFromTarget(); } None of the methods take any parameters. Instead, the implementation is expected to maintain a reference to the relevant GameObjectController and read that. However, I'm now trying to write unit tests for this. Obviously, it's necessary to use mocking, since I can't pass arguments directly. The way I'm doing it feels really brittle - what if another implementation comes along that uses the world query utilities in a different way? Really, I'm not testing the interface, I'm testing the implementation. Poor. The reason I used this pattern in the first place was to keep IThinkNPC implementation code clean: public BehaviorState RetreatTransition(BehaviorState currentBehavior) { if (sense.IsCollidingWithTarget()) { NPCUtils.TraceTransitionIfNeeded(ToString(), BehaviorState.ATTACK.ToString(), "is colliding with target"); return BehaviorState.ATTACK; } if (sense.IsSafeFromTarget() && sense.ClosestIlluminatingLight() == null) { return BehaviorState.WANDER; } if (sense.ClosestIlluminatingLight() != null && sense.SeesTarget()) { NPCUtils.TraceTransitionIfNeeded(ToString(), BehaviorState.ATTACK.ToString(), "collides with target"); return BehaviorState.CHASE; } return currentBehavior; } Perhaps the cleanliness isn't worth it, however. So, if ISenseNPC takes all the params it needs every time, I could make it static. Is there any problem with that?

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  • Why does my program not read full files?

    - by user593395
    I have written code in Java to read the content of a file. But it is working for small line of file only not for more than 1000 line of file. Please tell me me what error I have made in the below program. program: import java.io.DataInputStream; import java.io.DataOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.util.regex.Matcher; import java.util.regex.Pattern; public class aaru { public static void main(String args[]) throws FileNotFoundException { File sourceFile = new File("E:\\parser\\parse3.txt"); File destinationFile = new File("E:\\parser\\new.txt"); FileInputStream fileIn = new FileInputStream(sourceFile); FileOutputStream fileOut = new FileOutputStream(destinationFile); DataInputStream dataIn = new DataInputStream(fileIn); DataOutputStream dataOut = new DataOutputStream(fileOut); String str=""; String[] st; String sub[]=null; String word=""; String contents=""; String total=""; String stri="";; try { while((contents=dataIn.readLine())!=null) { total = contents.replaceAll(",",""); String str1=total.replaceAll("--",""); String str2=str1.replaceAll(";","" ); String str3=str2.replaceAll("&","" ); String str4=str3.replaceAll("^","" ); String str5=str4.replaceAll("#","" ); String str6=str5.replaceAll("!","" ); String str7=str6.replaceAll("/","" ); String str8=str7.replaceAll(":","" ); String str9=str8.replaceAll("]","" ); String str10=str9.replaceAll("\\?",""); String str11=str10.replaceAll("\\*",""); String str12=str11.replaceAll("\\'",""); Pattern pattern = Pattern.compile("\\s+", Pattern.CASE_INSENSITIVE | Pattern.DOTALL | Pattern.MULTILINE); Matcher matcher = pattern.matcher(str12); //boolean check = matcher.find(); String result=str12; Pattern p=Pattern.compile("^www\\.|\\@"); Matcher m=p.matcher(result); stri = m.replaceAll(" "); int i; int j; st=stri.split("\\."); for(i=0;i<st.length;i++) { st[i]=st[i].trim(); /*if(st[i].startsWith(" ")) st[i]=st[i].substring(1,st[i].length);*/ sub=st[i].split(" "); if(sub.length>1) { for(j=0;j<sub.length-1;j++) { word = word+sub[j]+","+sub[j+1]+"\r\n"; } } else { word = word+st[i]+"\r\n"; } } } System.out.println(word); dataOut.writeBytes(word+"\r\n"); fileIn.close(); fileOut.close(); dataIn.close(); dataOut.close(); } catch(Exception e) { System.out.print(e); } } }

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  • Number Algorithm

    - by James
    I've been struggling to wrap my head around this for some reason. I have 15 bits that represent a number. The bits must match a pattern. The pattern is defined in the way the bits start out: they are in the most flush-right representation of that pattern. So say the pattern is 1 4 1. The bits will be: 000000010111101 So the general rule is, take each number in the pattern, create that many bits (1, 4 or 1 in this case) and then have at least one space separating them. So if it's 1 2 6 1 (it will be random): 001011011111101 Starting with the flush-right version, I want to generate every single possible number that meets that pattern. The # of bits will be stored in a variable. So for a simple case, assume it's 5 bits and the initial bit pattern is: 00101. I want to generate: 00101 01001 01010 10001 10010 10100 I'm trying to do this in Objective-C, but anything resembling C would be fine. I just can't seem to come up with a good recursive algorithm for this. It makes sense in the above example, but when I start getting into 12431 and having to keep track of everything it breaks down.

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  • Using SiteMesh with RequestDispatcher's forward()

    - by Rob Hruska
    I'm attempting to integrate SiteMesh into a legacy application using Tomcat 5 as my a container. I have a main.jsp that I'm decorating with a simple decorator. In decorators.xml, I've just got one decorator defined: <decorators defaultdir="/decorators"> <decorator name="layout-main" page="layout-main.jsp"> <pattern>/jsp/main.jsp</pattern> </decorator> </decorators> This decorator works if I manually go to http://example.com/my-webapp/jsp/main.jsp. However, there are a few places where a servlet, instead of doing a redirect to a jsp, does a forward: getServletContext().getRequestDispatcher("/jsp/main.jsp").forward(request, response); This means that the URL remains at something like http://example.com/my-webapp/servlet/MyServlet instead of the jsp file and is therefore not being decorated, I presume since it doesn't match the pattern in decorators.xml. I can't do a <pattern>/*</pattern> because there are other jsps that do not need to be decorated by layout-main.jsp. I can't do a <pattern>/servlet/MyServlet*</pattern> because MyServlet may forward to main.jsp sometimes and perhaps error.jsp at other times. Is there a way to work around this without expansive changes to how the servlets work? Since it's a legacy app I don't have as much freedom to change things, so I'm hoping for something configuration-wise that will fix this. SiteMesh's documentation really isn't that great. I've been working mostly off the example application that comes with the distribution. I really like SiteMesh, and am hoping I can get it to work in this case.

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  • Splitting a string which contain multiple symbols to get specific values

    - by Eon Rusted du Plessis
    I cannot believe I am having trouble with this following string String filter = "name=Default;pattern=%%;start=Last;end=Now"; This is a short and possibly duplicate question, but how would I split this string to get: string Name = "Default"; string Pattern = "%%" ; string start = "Last" ; string end = "Now" ; Reason why I ask is my deadline is very soon, and this is literally the last thing I must do. I'm Panicking, and I'm stuck on this basic command. I tried: pattern = filter.Split(new string[] { "pattern=", ";" }, StringSplitOptions.RemoveEmptyEntries)[1]; //Gets the pattern startDate = filter.Split(new string[] { "start=", ";" }, StringSplitOptions.RemoveEmptyEntries)[1]; //Gets the start date I happen to get the pattern which I needed, but as soon as I try to split start, I get the value as "Pattern=%%" What can I do? Forgot to mention The list in this string which needs splitting may not be in any particular order . this is a single sample of a string which will be read out of a stringCollection (reading these filters from Properties.Settings.Filters

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  • Spring 3.0: Handler mapping issue

    - by Yaniv Cohen
    I am having a trouble mapping a specific URL request to one of the controllers in my project. the URL is : http://HOSTNAME/api/v1/profiles.json the war which is deployed is: api.war the error I get is the following: [PageNotFound] No mapping found for HTTP request with URI [/api/v1/profiles.json] in DispatcherServlet with name 'action' The configuration I have is the following: web.xml : <context-param> <param-name>contextConfigLocation</param-name> <param-value>/WEB-INF/applicationContext.xml,/WEB-INF/applicationContext-security.xml</param-value> </context-param> <!-- Cache Control filter --> <filter> <filter-name>cacheControlFilter</filter-name> <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class> </filter> <!-- Cache Control filter mapping --> <filter-mapping> <filter-name>cacheControlFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <!-- Spring security filter --> <filter> <filter-name>springSecurityFilterChain</filter-name> <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class> </filter> <!-- Spring security filter mapping --> <filter-mapping> <filter-name>springSecurityFilterChain</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <!-- Spring listener --> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <!-- Spring Controller --> <servlet> <servlet-name>action</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>action</servlet-name> <url-pattern>/v1/*</url-pattern> </servlet-mapping> The action-servlet.xml: <mvc:annotation-driven/> <bean id="contentNegotiatingViewResolver" class="org.springframework.web.servlet.view.ContentNegotiatingViewResolver"> <property name="favorPathExtension" value="true" /> <property name="favorParameter" value="true" /> <!-- default media format parameter name is 'format' --> <property name="ignoreAcceptHeader" value="false" /> <property name="order" value="1" /> <property name="mediaTypes"> <map> <entry key="html" value="text/html"/> <entry key="json" value="application/json" /> <entry key="xml" value="application/xml" /> </map> </property> <property name="viewResolvers"> <list> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/WEB-INF/jsp/"/> <property name="suffix" value=".jsp"/> <property name="viewClass" value="org.springframework.web.servlet.view.JstlView" /> </bean> </list> </property> <property name="defaultViews"> <list> <bean class="org.springframework.web.servlet.view.json.MappingJacksonJsonView" /> <bean class="org.springframework.web.servlet.view.xml.MarshallingView"> <constructor-arg> <bean class="org.springframework.oxm.xstream.XStreamMarshaller" /> </constructor-arg> </bean> </list> </property> </bean> the application context security: <sec:http auto-config='true' > <sec:intercept-url pattern="/login.*" filters="none"/> <sec:intercept-url pattern="/oauth/**" access="ROLE_USER" /> <sec:intercept-url pattern="/v1/**" access="ROLE_USER" /> <sec:intercept-url pattern="/request_token_authorized.jsp" access="ROLE_USER" /> <sec:intercept-url pattern="/**" access="ROLE_USER"/> <sec:form-login authentication-failure-url ="/login.html" default-target-url ="/login.html" login-page ="/login.html" login-processing-url ="/login.html" /> <sec:logout logout-success-url="/index.html" logout-url="/logout.html" /> </sec:http> the controller: @Controller public class ProfilesController { @RequestMapping(value = {"/v1/profiles"}, method = {RequestMethod.GET,RequestMethod.POST}) public void getProfilesList(@ModelAttribute("response") Response response) { .... } } the request never reaches this controller. Any ideas?

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  • grepping a substring from a grep result

    - by allentown
    Given a log file, I will usually do something like this: grep 'marker-1234' filter_log What is the difference in using '' or "" or nothing in the pattern? The above grep command will yield many thousands of lines; what I desire. Within those lines, There is usually one chunk of data I am after. Sometimes, I use awk to print out the fields I am after. In this case, the log format changes, I can't rely on position exclusively, not to mention, the actual logged data can push position forward. To make this understandable, lets say the log line contained an IP address, and that was all I was after, so I can later pipe it to sort and unique and get some tally counts. An example may be: 2010-04-08 some logged data, indetermineate chars - [marker-1234] (123.123.123.123) from: [email protected] to [email protected] [stat-xyz9876] The first grep command will give me many thousands of lines like the above, from there, I want to pipe it to something, probably sed, which can pull out a pattern within, and print only the pattern. For this example, using an the IP address would suffice. I tried. Is sed not able to understand [0-9]{1,3}. as a pattern? I had to [0-9][0-9][0-9]. which yielded strange results until the entire pattern created. This is not specific to an IP address, the pattern will change, but I can use that as a learning template. Thank you all.

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  • regexp uppercase to lowercase

    - by luccio
    Hi, is it possible to transform regexp pattern match to lowercase? var pattern:RegExp; var str:String = "HI guys"; pattern = /([A-Z]+)/g; str = str.replace(pattern, thisShouldBeLowerCase); Output should look like this: "hi guys" Thx

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  • Regular expressions

    - by Infinity
    Hello guys! I need a regular expression for findin a pattern. This is the pattern: id|name|code|mobile I created a pattern for this if I want to search by id (if id = 1): .*1.*|.*|.*|.* But it matches every pattern that contains number 1. What's the problem with it?

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  • Windows Azure Service Bus Scatter-Gather Implementation

    - by Alan Smith
    One of the more challenging enterprise integration patterns that developers may wish to implement is the Scatter-Gather pattern. In this article I will show the basic implementation of a scatter-gather pattern using the topic-subscription model of the windows azure service bus. I’ll be using the implementation in demos, and also as a lab in my training courses, and the pattern will also be included in the next release of my free e-book the “Windows Azure Service Bus Developer Guide”. The Scatter-Gather pattern answers the following scenario. How do you maintain the overall message flow when a message needs to be sent to multiple recipients, each of which may send a reply? Use a Scatter-Gather that broadcasts a message to multiple recipients and re-aggregates the responses back into a single message. The Enterprise Integration Patterns website provides a description of the Scatter-Gather pattern here.   The scatter-gather pattern uses a composite of the publish-subscribe channel pattern and the aggregator pattern. The publish-subscribe channel is used to broadcast messages to a number of receivers, and the aggregator is used to gather the response messages and aggregate them together to form a single message. Scatter-Gather Scenario The scenario for this scatter-gather implementation is an application that allows users to answer questions in a poll based voting scenario. A poll manager application will be used to broadcast questions to users, the users will use a voting application that will receive and display the questions and send the votes back to the poll manager. The poll manager application will receive the users’ votes and aggregate them together to display the results. The scenario should be able to scale to support a large number of users.   Scatter-Gather Implementation The diagram below shows the overall architecture for the scatter-gather implementation.       Messaging Entities Looking at the scatter-gather pattern diagram it can be seen that the topic-subscription architecture is well suited for broadcasting a message to a number of subscribers. The poll manager application can send the question messages to a topic, and each voting application can receive the question message on its own subscription. The static limit of 2,000 subscriptions per topic in the current release means that 2,000 voting applications can receive question messages and take part in voting. The vote messages can then be sent to the poll manager application using a queue. The voting applications will send their vote messages to the queue, and the poll manager will receive and process the vote messages. The questions topic and answer queue are created using the Windows Azure Developer Portal. Each instance of the voting application will create its own subscription in the questions topic when it starts, allowing the question messages to be broadcast to all subscribing voting applications. Data Contracts Two simple data contracts will be used to serialize the questions and votes as brokered messages. The code for these is shown below.   [DataContract] public class Question {     [DataMember]     public string QuestionText { get; set; } }     To keep the implementation of the voting functionality simple and focus on the pattern implementation, the users can only vote yes or no to the questions.   [DataContract] public class Vote {     [DataMember]     public string QuestionText { get; set; }       [DataMember]     public bool IsYes { get; set; } }     Poll Manager Application The poll manager application has been implemented as a simple WPF application; the user interface is shown below. A question can be entered in the text box, and sent to the topic by clicking the Add button. The topic and subscriptions used for broadcasting the messages are shown in a TreeView control. The questions that have been broadcast and the resulting votes are shown in a ListView control. When the application is started any existing subscriptions are cleared form the topic, clients are then created for the questions topic and votes queue, along with background workers for receiving and processing the vote messages, and updating the display of subscriptions.   public MainWindow() {     InitializeComponent();       // Create a new results list and data bind it.     Results = new ObservableCollection<Result>();     lsvResults.ItemsSource = Results;       // Create a token provider with the relevant credentials.     TokenProvider credentials =         TokenProvider.CreateSharedSecretTokenProvider         (AccountDetails.Name, AccountDetails.Key);       // Create a URI for the serivce bus.     Uri serviceBusUri = ServiceBusEnvironment.CreateServiceUri         ("sb", AccountDetails.Namespace, string.Empty);       // Clear out any old subscriptions.     NamespaceManager = new NamespaceManager(serviceBusUri, credentials);     IEnumerable<SubscriptionDescription> subs =         NamespaceManager.GetSubscriptions(AccountDetails.ScatterGatherTopic);     foreach (SubscriptionDescription sub in subs)     {         NamespaceManager.DeleteSubscription(sub.TopicPath, sub.Name);     }       // Create the MessagingFactory     MessagingFactory factory = MessagingFactory.Create(serviceBusUri, credentials);       // Create the topic and queue clients.     ScatterGatherTopicClient =         factory.CreateTopicClient(AccountDetails.ScatterGatherTopic);     ScatterGatherQueueClient =         factory.CreateQueueClient(AccountDetails.ScatterGatherQueue);       // Start the background worker threads.     VotesBackgroundWorker = new BackgroundWorker();     VotesBackgroundWorker.DoWork += new DoWorkEventHandler(ReceiveMessages);     VotesBackgroundWorker.RunWorkerAsync();       SubscriptionsBackgroundWorker = new BackgroundWorker();     SubscriptionsBackgroundWorker.DoWork += new DoWorkEventHandler(UpdateSubscriptions);     SubscriptionsBackgroundWorker.RunWorkerAsync(); }     When the poll manager user nters a question in the text box and clicks the Add button a question message is created and sent to the topic. This message will be broadcast to all the subscribing voting applications. An instance of the Result class is also created to keep track of the votes cast, this is then added to an observable collection named Results, which is data-bound to the ListView control.   private void btnAddQuestion_Click(object sender, RoutedEventArgs e) {     // Create a new result for recording votes.     Result result = new Result()     {         Question = txtQuestion.Text     };     Results.Add(result);       // Send the question to the topic     Question question = new Question()     {         QuestionText = result.Question     };     BrokeredMessage msg = new BrokeredMessage(question);     ScatterGatherTopicClient.Send(msg);       txtQuestion.Text = ""; }     The Results class is implemented as follows.   public class Result : INotifyPropertyChanged {     public string Question { get; set; }       private int m_YesVotes;     private int m_NoVotes;       public event PropertyChangedEventHandler PropertyChanged;       public int YesVotes     {         get { return m_YesVotes; }         set         {             m_YesVotes = value;             NotifyPropertyChanged("YesVotes");         }     }       public int NoVotes     {         get { return m_NoVotes; }         set         {             m_NoVotes = value;             NotifyPropertyChanged("NoVotes");         }     }       private void NotifyPropertyChanged(string prop)     {         if(PropertyChanged != null)         {             PropertyChanged(this, new PropertyChangedEventArgs(prop));         }     } }     The INotifyPropertyChanged interface is implemented so that changes to the number of yes and no votes will be updated in the ListView control. Receiving the vote messages from the voting applications is done asynchronously, using a background worker thread.   // This runs on a background worker. private void ReceiveMessages(object sender, DoWorkEventArgs e) {     while (true)     {         // Receive a vote message from the queue         BrokeredMessage msg = ScatterGatherQueueClient.Receive();         if (msg != null)         {             // Deserialize the message.             Vote vote = msg.GetBody<Vote>();               // Update the results.             foreach (Result result in Results)             {                 if (result.Question.Equals(vote.QuestionText))                 {                     if (vote.IsYes)                     {                         result.YesVotes++;                     }                     else                     {                         result.NoVotes++;                     }                     break;                 }             }               // Mark the message as complete.             msg.Complete();         }       } }     When a vote message is received, the result that matches the vote question is updated with the vote from the user. The message is then marked as complete. A second background thread is used to update the display of subscriptions in the TreeView, with a dispatcher used to update the user interface. // This runs on a background worker. private void UpdateSubscriptions(object sender, DoWorkEventArgs e) {     while (true)     {         // Get a list of subscriptions.         IEnumerable<SubscriptionDescription> subscriptions =             NamespaceManager.GetSubscriptions(AccountDetails.ScatterGatherTopic);           // Update the user interface.         SimpleDelegate setQuestion = delegate()         {             trvSubscriptions.Items.Clear();             TreeViewItem topicItem = new TreeViewItem()             {                 Header = AccountDetails.ScatterGatherTopic             };               foreach (SubscriptionDescription subscription in subscriptions)             {                 TreeViewItem subscriptionItem = new TreeViewItem()                 {                     Header = subscription.Name                 };                 topicItem.Items.Add(subscriptionItem);             }             trvSubscriptions.Items.Add(topicItem);               topicItem.ExpandSubtree();         };         this.Dispatcher.BeginInvoke(DispatcherPriority.Send, setQuestion);           Thread.Sleep(3000);     } }       Voting Application The voting application is implemented as another WPF application. This one is more basic, and allows the user to vote “Yes” or “No” for the questions sent by the poll manager application. The user interface for that application is shown below. When an instance of the voting application is created it will create a subscription in the questions topic using a GUID as the subscription name. The application can then receive copies of every question message that is sent to the topic. Clients for the new subscription and the votes queue are created, along with a background worker to receive the question messages. The voting application is set to receiving mode, meaning it is ready to receive a question message from the subscription.   public MainWindow() {     InitializeComponent();       // Set the mode to receiving.     IsReceiving = true;       // Create a token provider with the relevant credentials.     TokenProvider credentials =         TokenProvider.CreateSharedSecretTokenProvider         (AccountDetails.Name, AccountDetails.Key);       // Create a URI for the serivce bus.     Uri serviceBusUri = ServiceBusEnvironment.CreateServiceUri         ("sb", AccountDetails.Namespace, string.Empty);       // Create the MessagingFactory     MessagingFactory factory = MessagingFactory.Create(serviceBusUri, credentials);       // Create a subcription for this instance     NamespaceManager mgr = new NamespaceManager(serviceBusUri, credentials);     string subscriptionName = Guid.NewGuid().ToString();     mgr.CreateSubscription(AccountDetails.ScatterGatherTopic, subscriptionName);       // Create the subscription and queue clients.     ScatterGatherSubscriptionClient = factory.CreateSubscriptionClient         (AccountDetails.ScatterGatherTopic, subscriptionName);     ScatterGatherQueueClient =         factory.CreateQueueClient(AccountDetails.ScatterGatherQueue);       // Start the background worker thread.     BackgroundWorker = new BackgroundWorker();     BackgroundWorker.DoWork += new DoWorkEventHandler(ReceiveMessages);     BackgroundWorker.RunWorkerAsync(); }     I took the inspiration for creating the subscriptions in the voting application from the chat application that uses topics and subscriptions blogged by Ovais Akhter here. The method that receives the question messages runs on a background thread. If the application is in receive mode, a question message will be received from the subscription, the question will be displayed in the user interface, the voting buttons enabled, and IsReceiving set to false to prevent more questing from being received before the current one is answered.   // This runs on a background worker. private void ReceiveMessages(object sender, DoWorkEventArgs e) {     while (true)     {         if (IsReceiving)         {             // Receive a question message from the topic.             BrokeredMessage msg = ScatterGatherSubscriptionClient.Receive();             if (msg != null)             {                 // Deserialize the message.                 Question question = msg.GetBody<Question>();                   // Update the user interface.                 SimpleDelegate setQuestion = delegate()                 {                     lblQuestion.Content = question.QuestionText;                     btnYes.IsEnabled = true;                     btnNo.IsEnabled = true;                 };                 this.Dispatcher.BeginInvoke(DispatcherPriority.Send, setQuestion);                 IsReceiving = false;                   // Mark the message as complete.                 msg.Complete();             }         }         else         {             Thread.Sleep(1000);         }     } }     When the user clicks on the Yes or No button, the btnVote_Click method is called. This will create a new Vote data contract with the appropriate question and answer and send the message to the poll manager application using the votes queue. The user voting buttons are then disabled, the question text cleared, and the IsReceiving flag set to true to allow a new message to be received.   private void btnVote_Click(object sender, RoutedEventArgs e) {     // Create a new vote.     Vote vote = new Vote()     {         QuestionText = (string)lblQuestion.Content,         IsYes = ((sender as Button).Content as string).Equals("Yes")     };       // Send the vote message.     BrokeredMessage msg = new BrokeredMessage(vote);     ScatterGatherQueueClient.Send(msg);       // Update the user interface.     lblQuestion.Content = "";     btnYes.IsEnabled = false;     btnNo.IsEnabled = false;     IsReceiving = true; }     Testing the Application In order to test the application, an instance of the poll manager application is started; the user interface is shown below. As no instances of the voting application have been created there are no subscriptions present in the topic. When an instance of the voting application is created the subscription will be displayed in the poll manager. Now that a voting application is subscribing, a questing can be sent from the poll manager application. When the message is sent to the topic, the voting application will receive the message and display the question. The voter can then answer the question by clicking on the appropriate button. The results of the vote are updated in the poll manager application. When two more instances of the voting application are created, the poll manager will display the new subscriptions. More questions can then be broadcast to the voting applications. As the question messages are queued up in the subscription for each voting application, the users can answer the questions in their own time. The vote messages will be received by the poll manager application and aggregated to display the results. The screenshots of the applications part way through voting are shown below. The messages for each voting application are queued up in sequence on the voting application subscriptions, allowing the questions to be answered at different speeds by the voters.

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  • How can we implement change notification propagation for WPF and SL in the MVVM pattern?

    - by Firoso
    Here's an example scenario targetting MVVM WPF/SL development: View data binds to view model Property "Target" "Target" exposes a field of an object called "data" that exists in the local application model, called "Original" when "Original" changes, it should raise notification to the view model and then propogate that change notification to the View. Here are the solutions I've come up with, but I don't like any of them all that much. I'm looking for other ideas, by the time we come up with something rock solid I'm certain Microsoft will have released .NET 5 with WPF/SL extensions for better tools for MVVM development. For now the question is, "What have you done to solve this problem and how has it worked out for you?" Option 1. Proposal: Attach a handler to data's PropertyChanged event that watches for string values of properties it cares about that might have changed, and raises the appropriate notification. Why I don't like it: Changes don't bubble naturally, objects must be explicitly watched, if data changes to a new source, events must be un-registered/registered. Why I kind of like it: I get explicit control over propogation of changes, and I don't have to use any types that belong at a higher level of the application such as dependancy properties. Option 2. Proposal: Attach a handler to data's PropertyChanged event that re-raises the event across all properties using the name property name. Why I don't like it: This is essentially the same as option 1, but less intelligent, and forces me to never change my property names, as they have to be the same as the property names on data Why I kind of like it: It's very easy to set up and I don't have to think about it... Then again if I try to think, and change names to things that make sense, I shoot myself in the foot, and then I have to think about it! Option 3. Proposal: Inherit my view model from dependancy object, and notify binding sources of changes directly. Why I don't like it: I'm not even 100% sure dependancy properties/objects can DO this, it was just a thought to look into. Also I don't personally feel that WPF/SL types like Dep Obj belong at the view model level. Why I kind of like it: IF it has the capability that I'm seeking then it's a good answer! minus that pesky layering issue. Option 4. Proposal: Use a consistant agent messaging system based off of Task Parallels DataFlow Library to propogate everything through linked pipelining. Why I don't like it: I've never tried this, and somehow I think it will be lacking, plus it requires me to think about my code completely differently all the way around. Why I kind of like it: It has the possiblity of allowing me to do some VERY fun manipulations with a push based data model and using ActionBlocks as validation AND setters to then privately change view model properties and explicitly control PropertyChanged notifications.

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  • How can I print lines that match a pattern in Perl?

    - by kivien
    Assuming the file.txt having just one sentence per line as follows:- John Depp is a great guy. He is very inteligent. He can do anything. Come and meet John Depp. The perl code is as follows:- open ( FILE, "file.txt" ) || die "can't open file!"; @lines = <FILE>; close (FILE); $string = "John Depp"; foreach $line (@lines) { if ($line =~ $string) { print "$line"; } } The output is going to be first and fourth line. I want to make it working for the file having random line breaks rather than one English sentence per line. I mean it should also work for the following:- John Depp is a great guy. He is very inteligent. He can do anything. Come and meet John Depp. The output should be first and fourth sentence. Any ideas please?

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  • What's the best Communication Pattern for EJB3-based applications?

    - by Hank
    I'm starting a JEE project that needs to be strongly scalable. So far, the concept was: several Message Driven Beans, responsible for different parts of the architecture each MDB has a Session Bean injected, handling the business logic a couple of Entity Beans, providing access to the persistence layer communication between the different parts of the architecture via Request/Reply concept via JMS messages: MDB receives msg containing activity request uses its session bean to execute necessary business logic returns response object in msg to original requester The idea was that by de-coupling parts of the architecture from each other via the message bus, there is no limit to the scalability. Simply start more components - as long as they are connected to the same bus, we can grow and grow. Unfortunately, we're having massive problems with the request-reply concept. Transaction Mgmt seems to be in our way plenty. It seams that session beans are not supposed to consume messages?! Reading http://blogs.sun.com/fkieviet/entry/request_reply_from_an_ejb and http://forums.sun.com/message.jspa?messageID=10338789, I get the feeling that people actually recommend against the request/reply concept for EJBs. If that is the case, how do you communicate between your EJBs? (Remember, scalability is what I'm after) Details of my current setup: MDB 1 'TestController', uses (local) SLSB 1 'TestService' for business logic TestController.onMessage() makes TestService send a message to queue XYZ and requests a reply TestService uses Bean Managed Transactions TestService establishes a connection & session to the JMS broker via a joint connection factory upon initialization (@PostConstruct) TestService commits the transaction after sending, then begins another transaction and waits 10 sec for the response Message gets to MDB 2 'LocationController', which uses (local) SLSB 2 'LocationService' for business logic LocationController.onMessage() makes LocationService send a message back to the requested JMSReplyTo queue Same BMT concept, same @PostConstruct concept all use the same connection factory to access the broker Problem: The first message gets send (by SLSB 1) and received (by MDB 2) ok. The sending of the returning message (by SLSB 2) is fine as well. However, SLSB 1 never receives anything - it just times out. I tried without the messageSelector, no change, still no receiving message. Is it not ok to consume message by a session bean? SLSB 1 - TestService.java @Resource(name = "jms/mvs.MVSControllerFactory") private javax.jms.ConnectionFactory connectionFactory; @PostConstruct public void initialize() { try { jmsConnection = connectionFactory.createConnection(); session = jmsConnection.createSession(false, Session.AUTO_ACKNOWLEDGE); System.out.println("Connection to JMS Provider established"); } catch (Exception e) { } } public Serializable sendMessageWithResponse(Destination reqDest, Destination respDest, Serializable request) { Serializable response = null; try { utx.begin(); Random rand = new Random(); String correlationId = rand.nextLong() + "-" + (new Date()).getTime(); // prepare the sending message object ObjectMessage reqMsg = session.createObjectMessage(); reqMsg.setObject(request); reqMsg.setJMSReplyTo(respDest); reqMsg.setJMSCorrelationID(correlationId); // prepare the publishers and subscribers MessageProducer producer = session.createProducer(reqDest); // send the message producer.send(reqMsg); System.out.println("Request Message has been sent!"); utx.commit(); // need to start second transaction, otherwise the first msg never gets sent utx.begin(); MessageConsumer consumer = session.createConsumer(respDest, "JMSCorrelationID = '" + correlationId + "'"); jmsConnection.start(); ObjectMessage respMsg = (ObjectMessage) consumer.receive(10000L); utx.commit(); if (respMsg != null) { response = respMsg.getObject(); System.out.println("Response Message has been received!"); } else { // timeout waiting for response System.out.println("Timeout waiting for response!"); } } catch (Exception e) { } return response; } SLSB 2 - LocationService.Java (only the reply method, rest is same as above) public boolean reply(Message origMsg, Serializable o) { boolean rc = false; try { // check if we have necessary correlationID and replyTo destination if (!origMsg.getJMSCorrelationID().equals("") && (origMsg.getJMSReplyTo() != null)) { // prepare the payload utx.begin(); ObjectMessage msg = session.createObjectMessage(); msg.setObject(o); // make it a response msg.setJMSCorrelationID(origMsg.getJMSCorrelationID()); Destination dest = origMsg.getJMSReplyTo(); // send it MessageProducer producer = session.createProducer(dest); producer.send(msg); producer.close(); System.out.println("Reply Message has been sent"); utx.commit(); rc = true; } } catch (Exception e) {} return rc; } sun-resources.xml <admin-object-resource enabled="true" jndi-name="jms/mvs.LocationControllerRequest" res-type="javax.jms.Queue" res-adapter="jmsra"> <property name="Name" value="mvs.LocationControllerRequestQueue"/> </admin-object-resource> <admin-object-resource enabled="true" jndi-name="jms/mvs.LocationControllerResponse" res-type="javax.jms.Queue" res-adapter="jmsra"> <property name="Name" value="mvs.LocationControllerResponseQueue"/> </admin-object-resource> <connector-connection-pool name="jms/mvs.MVSControllerFactoryPool" connection-definition-name="javax.jms.QueueConnectionFactory" resource-adapter-name="jmsra"/> <connector-resource enabled="true" jndi-name="jms/mvs.MVSControllerFactory" pool-name="jms/mvs.MVSControllerFactoryPool" />

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  • where to set wait cursor in long operation in MVP pattern?

    - by Benny
    For a long operation that will be executed in presenter, where to set the wait cursor? in View? the view shouldn't know too much about business logic, it is passive. in presenter? seems odd in presenter to call UI code. add method to View interface, like SetWait(bool), and call it in presenter? So what do you think?

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  • Wrappers/law of demeter seems to be an anti-pattern...

    - by Robert Fraser
    I've been reading up on this "Law of Demeter" thing, and it (and pure "wrapper" classes in general) seem to generally be anti patterns. Consider an implementation class: class Foo { void doSomething() { /* whatever */ } } Now consider two different implementations of another class: class Bar1 { private static Foo _foo = new Foo(); public static Foo getFoo() { return _foo; } } class Bar2 { private static Foo _foo = new Foo(); public static void doSomething() { _foo.doSomething(); } } And the ways to call said methods: callingMethod() { Bar1.getFoo().doSomething(); // Version 1 Bar2.doSomething(); // Version 2 } At first blush, version 1 seems a bit simpler, and follows the "rule of Demeter", hide Foo's implementation, etc, etc. But this ties any changes in Foo to Bar. For example, if a parameter is added to doSomething, then we have: class Foo { void doSomething(int x) { /* whatever */ } } class Bar1 { private static Foo _foo = new Foo(); public static Foo getFoo() { return _foo; } } class Bar2 { private static Foo _foo = new Foo(); public static void doSomething(int x) { _foo.doSomething(x); } } callingMethod() { Bar1.getFoo().doSomething(5); // Version 1 Bar2.doSomething(5); // Version 2 } In both versions, Foo and callingMethod need to be changed, but in Version 2, Bar also needs to be changed. Can someone explain the advantage of having a wrapper/facade (with the exception of adapters or wrapping an external API or exposing an internal one).

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  • How to use Page Object pattern with Cucumber and Webrat / Selenium?

    - by Will Sargent
    I'm looking at a cucumber test suite that is somewhat brittle right now; many small steps, and no knowledge of the page itself. I'd like to factor out the logic involved in the step definitions inside a series of Selenium PageObjects. As seen here. However, because I'm using Webrat and not Selenium, everything has to go through the Webrat model. So I cannot do class MyPage < Selenium::WebPage end because that adds a direct dependency. So I have to route everything through Webrat while still maintaining the Selenium Page object goodness. No documentation on this that I can see: if someone has anything on Webrat + PageModel I'd love to see it.

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  • Can you find a pattern to sync files knowing only dates and filenames?

    - by Robert MacLean
    Imagine if you will a operating system that had the following methods for files Create File: Creates (writes) a new file to disk. Calling this if a file exists causes a fault. Update File: Updates an existing file. Call this if a file doesn't exist causes a fault. Read File: Reads data from a file. Enumerate files: Gets all files in a folder. Files themselves in this operating system only have the following meta data: Created Time: The original date and time the file was created, by the Create File method. Modified Time: The date and time the file was last modified by the Update File method. If the file has never been modified, this will equal the Create Time. You have been given the task of writing an application which will sync the files between two directories (lets call them bill and ted) on a machine. However it is not that simple, the client has required that The application never faults (see methods above). That while the application is running the users can add and update files and those will be sync'd next time the application runs. Files can be added to either the ted or bill directories. File names cannot be altered. The application will perform one sync per time it is run. The application must be almost entirely in memory, in other words you cannot create a log of filenames and write that to disk and then check that the next time. The exception to point 6 is that you can store date and times between runs. Each date/time is associated with a key labeled A through J (so you have 10 to use) so you can compare keys between runs. There is no way to catch exceptions in the application. Answer will be accepted based on the following conditions: First answer to meet all requirements will be accepted. If there is no way to meet all requirements, the answer which ensures the smallest amount of missed changes per sync will be accepted. A bounty will be created (100 points) as soon as possible for the prize. The winner will be selected one day before the bounty ends. Please ask questions in the comments and I will gladly update and refine the question on those.

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