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  • Business rule validation of hierarchical list of objects ASP.NET MVC

    - by SergeanT
    I have a list of objects that are organized in a tree using a Depth property: public class Quota { [Range(0, int.MaxValue, ErrorMessage = "Please enter an amount above zero.")] public int Amount { get; set; } public int Depth { get; set; } [Required] [RegularExpression("^[a-zA-Z]+$")] public string Origin { get; set; } // ... another properties with validation attributes } For data example (amount - origin) 100 originA 200 originB 50 originC 150 originD the model data looks like: IList<Quota> model = new List<Quota>(); model.Add(new Quota{ Amount = 100, Depth = 0, Origin = "originA"); model.Add(new Quota{ Amount = 200, Depth = 0, Origin = "originB"); model.Add(new Quota{ Amount = 50, Depth = 1, Origin = "originC"); model.Add(new Quota{ Amount = 150, Depth = 1, Orinig = "originD"); Editing of the list Then I use Editing a variable length list, ASP.NET MVC 2-style to raise editing of the list. Controller actions QuotaController.cs: public class QuotaController : Controller { // // GET: /Quota/EditList public ActionResult EditList() { IList<Quota> model = // ... assigments as in example above; return View(viewModel); } // // POST: /Quota/EditList [HttpPost] public ActionResult EditList(IList<Quota> quotas) { if (ModelState.IsValid) { // ... save logic return RedirectToAction("Details"); } return View(quotas); // Redisplay the form with errors } // ... other controller actions } View EditList.aspx: <%@ Page Title="" Language="C#" ... Inherits="System.Web.Mvc.ViewPage<IList<Quota>>" %> ... <h2>Edit Quotas</h2> <%=Html.ValidationSummary("Fix errors:") %> <% using (Html.BeginForm()) { foreach (var quota in Model) { Html.RenderPartial("QuotaEditorRow", quota); } %> <% } %> ... Partial View QuotaEditorRow.ascx: <%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<Quota>" %> <div class="quotas" style="margin-left: <%=Model.Depth*45 %>px"> <% using (Html.BeginCollectionItem("Quotas")) { %> <%=Html.HiddenFor(m=>m.Id) %> <%=Html.HiddenFor(m=>m.Depth) %> <%=Html.TextBoxFor(m=>m.Amount, new {@class = "number", size = 5})%> <%=Html.ValidationMessageFor(m=>m.Amount) %> Origin: <%=Html.TextBoxFor(m=>m.Origin)%> <%=Html.ValidationMessageFor(m=>m.Origin) %> ... <% } %> </div> Business rule validation How do I implement validation of business rule: Amount of quota and sum of amounts of nested quotas should equal (e.a. 200 = 50 + 150 in example)? I want to appropriate inputs Html.TextBoxFor(m=>m.Amount) be highlighted red if the rule is broken for it. In example if user enters not 200, but 201 - it should be red on submit. Using sever validation only. Thanks a lot for any advise.

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  • How to make @BeforeClass run prior Spring TestContext loads up ?

    - by lisak
    Hey, it should be piece of cake for programmers using testNG. I have this scenario @ContextConfiguration(locations={"customer-form-portlet.xml", "classpath:META-INF2/base-spring.xml" }) public class BaseTestCase extends AbstractTestNGSpringContextTests { ... @BeforeClass public void setUpClass() throws Exception { But I'd need the spring context to be load up after @BeforeClass. I I came up with overriding AbstractTestNGSpringContextTests methods : @BeforeClass(alwaysRun = true) protected void springTestContextBeforeTestClass() throws Exception { this.testContextManager.beforeTestClass(); } @BeforeClass(alwaysRun = true, dependsOnMethods = "springTestContextBeforeTestClass") protected void springTestContextPrepareTestInstance() throws Exception { this.testContextManager.prepareTestInstance(this); } and make my method @BeforeClass(alwaysRun = true, dependsOnMethods = "setUpClass") protected void springTestContextPrepareTestClass() throws Exception { } But then I get : Caused by: org.testng.TestNGException: org.springframework.test.context.testng.AbstractTestNGSpringContextTests.springTestContextPrepareTestInstance() is not allowed to depend on protected void org.springframework.test.context.testng.AbstractTestNGSpringContextTests.springTestContextBeforeTestClass() throws java.lang.Exception Make it public also doesn't help. Could please anybody mention here if it can be done in a working manner :-) I know that I could load the testContext manually, but that wouldn't be so fancy. It works like this, but TestContextManager is not visible so I can't call prepareTestInstance() method on it : @Override @BeforeClass(alwaysRun = true, dependsOnMethods = "setUpClass") public void springTestContextPrepareTestInstance() throws Exception { }

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  • using extends with Java Generics

    - by Sandro
    Lets say that I have the following code: public class Shelter<A extends Animal, B extends Animal> { List<A> topFloor = new Vector<A>(); List<B> bottomFloor = new Vector<B>(); public A getFirstTopFloorAnimal(){return topFloor.firstElement();} public B getFirstBottomFloorAnimal(){return bottomFloor.firstElement();} //This compiles but when I try to use it, it only returns objects public List<Animal> getAnimals() { Vector a = new Vector(topFloor); a.addAll(bottomFloor); return a; } } Now for somereason the following code compiles. But when I try to use getAnimals() I get a of objects instead of Animal. Any ideas why this is? Does this have to do with the List is NOT a List idea in the Generics tutorial? Thank you.

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  • Problem with UserControl with custom Dependency Property

    - by Mathias Koch
    Hi, I'm writing a user control with a dependency property for a search text called SearchText. It is a dependency property because I want to allow consumers of the control to use data binding. The user control contains a WPF TextBox where the user can enter the search text. I could use data binding to connect the SearchText dependency property of the user control with the Text dependency property of the TextBox, but this binding only fires when the text box looses input focus. What I want is SearchText to be updated after every change of Text. So I have added a TextChanged event handler to the user control where I set SearchText to the value of Text. My Problem is, the SearchText binding doesn't work, the source never gets updated. What am I doing wrong? Here's the relevant part of the user controls code-behind: public partial class UserControlSearchTextBox : UserControl { public string SearchText { get { return (string)GetValue(SearchTextProperty); } set { SetValue(SearchTextProperty, value); } } public static readonly DependencyProperty SearchTextProperty = DependencyProperty.Register("SearchText", typeof(string), typeof(UserControlSearchTextBox), new UIPropertyMetadata("")); private void TextBox_TextChanged(object sender, TextChangedEventArgs e) { SearchText = ((TextBox)sender).Text; } ... } The window that contains an instance of the user control has its DataContext set to an object that has a property also called SearchText. <uc:UserControlSearchTextBox SearchText="{Binding SearchText}" /> The data context of the Window: public class DataSourceUserManual : DataSourceBase { private string _searchText; public string SearchText { get { return _searchText; } set { _searchText = value; ... OnPropertyChanged("SearchText"); } } } Unfortunately, this setter is not called when I type into the text box. Any ideas?

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  • Injecting Entitymanager via XML and not annnotations.

    - by user355543
    What I am trying to do is inject through XML almost the same way that is done through A @PersistenceContext annotation. I am in need of this because of the fact I have different entity managers I need to inject into the same DAO. The databases mirror one another and I would rather have 1 base class and for instances of that base class then create multiple classes just so I can use the @PersistenceContext annotation. Here is my example. This is what I am doing now and it works. public class ItemDaoImpl { protected EntityManager entityManager; public List<Item> getItems() { Query query = entityManager.createQuery("select i from Item i"); List<Item> s = (List<Item>)query.getResultList(); return s; } public void setEntityManger(EntityManager entityManager) { this.entityManager = entityManager; } } @Repository(value = "itemDaoStore2") public class ItemDaoImplStore2 extends ItemDaoImpl { @PersistenceContext(unitName = "persistence_unit_2") public void setEntityManger(EntityManager entityManager) { this.entityManager = entityManager; } } @Repository(value = "itemDaoStore1") public class ItemDaoImplStore1 extends ItemDaoImpl { @PersistenceContext(unitName = "persistence_unit_1") public void setEntityManger(EntityManager entityManager) { this.entityManager = entityManager; } } TransactionManagers, EntityManagers are defined below... <!-- Registers Spring's standard post-processors for annotation-based configuration like @Repository --> <context:annotation-config /> <!-- For @Transactional annotations --> <tx:annotation-driven transaction-manager="transactionManager1" /> <tx:annotation-driven transaction-manager="transactionManager2" /> <!-- This makes Spring perform @PersistenceContext/@PersitenceUnit injection: --> <bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor"/> <!-- Drives transactions using local JPA APIs --> <bean id="transactionManager1" class="org.springframework.orm.jpa.JpaTransactionManager"> <property name="entityManagerFactory" ref="entityManagerFactory1" /> </bean> <bean id="transactionManager2" class="org.springframework.orm.jpa.JpaTransactionManager"> <property name="entityManagerFactory" ref="entityManagerFactory2" /> </bean> <bean id="entityManagerFactory1" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"> <property name="persistenceUnitName" value="persistence_unit_1"/> ... </bean> <bean id="entityManagerFactory2" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"> <property name="persistenceUnitName" value="persistence_unit_2"/> ... </bean> What I want to do is to NOT create classes ItemDaoImplStore2 or ItemDaoImplStore1. I want to have these as instances of ItemDaoImpl via xml instead. I do not know how to inject the entitymanager properly though. I want to simulate annotating this as a 'Repository' annotation, and I also want to be able to specify what entityManager to inject by the persistence unit name. I want something similar to the below using XML instead. <!-- Somehow annotate this instance as a @Repository annotation --> <bean id="itemDaoStore1" class="ItemDaoImpl"> <!-- Does not work since it is a LocalContainerEntityManagerFactoryBean--> <!-- Also I would perfer to do it the same way PersistenceContext works and only provide the persistence unit name. I would like to be able to specify persistence_unit_1--> <property name="entityManager" ref="entityManagerFactory1"/> </bean> <!-- Somehow annotate this instance as a @Repository annotation --> <bean id="itemDaoStore2" class="ItemDaoImpl"> <!-- Does not work since it is a LocalContainerEntityManagerFactoryBean--> <!-- Also I would perfer to do it the same way PersistenceContext works and only provide the persistence unit name. I would like to be able to specify persistence_unit_2--> <property name="entityManager" ref="entityManagerFactory2"/> </bean>

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  • NoClassDefFoundError: HttpClient 4 (APACHE)

    - by Pujan Srivastava
    Hello All, I am using HC APACHE. I have added both httpcore-4.0.1.jar and httpclient-4.0.1.jar in the classpath of netbeans. I am getting error: java.lang.NoClassDefFoundError: org/apache/http/impl/client/DefaultHttpClient My Code is as follows. Please help. import org.apache.http.client.HttpClient; import org.apache.http.client.ResponseHandler; import org.apache.http.client.methods.HttpGet; import org.apache.http.impl.client.BasicResponseHandler; import org.apache.http.impl.client.DefaultHttpClient; public class HttpClientManager { public HttpClient httpclient; public HttpClientManager() { this.init(); } public void init() { try { httpclient = new DefaultHttpClient(); } catch (Exception e) { e.printStackTrace(); } } public void getCourseList() { String url = "http://exnet.in.th/api.php?username=demoinst&ha=2b62560&type=instructor"; HttpGet httpget = new HttpGet(url); ResponseHandler<String> responseHandler = new BasicResponseHandler(); try { String responseBody = httpclient.execute(httpget, responseHandler); System.out.println(responseBody); } catch (Exception e) { } } }

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  • how to parametrize an import in a View?

    - by Gianluca Colucci
    Hello everybody, I am looking for some help and I hope that some good soul out there will be able to give me a hint :) In the app I am building, I have a View. When an instance of this View gets created, it "imports" (MEF) the corresponding ViewModel. Here some code: public partial class ContractEditorView : Window { public ContractEditorView () { InitializeComponent(); CompositionInitializer.SatisfyImports(this); } [Import(ViewModelTypes.ContractEditorViewModel)] public object ViewModel { set { DataContext = value; } } } and here is the export for the ViewModel: [PartCreationPolicy(CreationPolicy.NonShared)] [Export(ViewModelTypes.ContractEditorViewModel)] public class ContractEditorViewModel: ViewModelBase { public ContractEditorViewModel() { _contract = new Models.Contract(); } } Now, this works if I want to open a new window to create a new contract... But it does not if I want to use the same window to edit an existing contract... In other words, I would like to add a second construct both in the View and in the ViewModel: the original constructor would accept no parameters and therefore it would create a new contract; the new construct - the one I'd like to add - I'd like to pass an ID so that I can load a given entity... What I don't understand is how to pass this ID to the ViewModel import... Thanks in advance, Cheers, Gianluca.

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  • How come this image won't resize to fit the sprite?

    - by George Edison
    I have this snippet of ActionScript code that is supposed to resize an image to fit the sprite: package { import flash.display.Sprite; import flash.display.Bitmap; import flash.events.Event; public class Main extends Sprite { [Embed(source = 'img.png')] private var TheImage:Class; public static const TheImageWidth:Number = 1300; public static const TheImageHeight:Number = 1300; public function Main():void { if (stage) init(); else addEventListener(Event.ADDED_TO_STAGE, init); } private function init(e:Event = null):void { removeEventListener(Event.ADDED_TO_STAGE, init); // entry point var image:Bitmap = new TheImage(); addChild(image); image.scaleX = width / TheImageWidth; image.scaleY = height / TheImageHeight; } } } Why isn't it working?

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  • Is it a jaxb bug?

    - by wd-shuang
    I take a scheme, its element definition as follows: <xs:complexType name="OriginalMessageContents1"> <xs:sequence> <xs:any namespace="##any" processContents="skip"/> <xs:any namespace="##any" processContents="skip" minOccurs="0"/> </xs:sequence> </xs:complexType> I use xjb to export java file,xjb as follow: <jxb:bindings version="2.0" xmlns:jxb="http://java.sun.com/xml/ns/jaxb" xmlns:xs="http://www.w3.org/2001/XMLSchema"> <jxb:bindings schemaLocation="ibps.706.001.01.xsd" node="/xs:schema"> <jxb:bindings node="//xs:complexType[@name='OriginalMessageContents1']/xs:sequence"> <jxb:bindings node=".//xs:any[position()=1]"> <jxb:property name="anyOne"/> </jxb:bindings> <jxb:bindings node=".//xs:any[position()=2]"> <jxb:property name="anyTwo"/> </jxb:bindings> </jxb:bindings> </jxb:bindings> </jxb:bindings> Java as: @XmlAccessorType(XmlAccessType.FIELD) @XmlType(name = "OriginalMessageContents1", propOrder = { "anyOne", "anyTwo" }) public class OriginalMessageContents1 { @XmlAnyElement protected Element anyOne; @XmlAnyElement protected Element anyTwo; public Element getAnyOne() { return anyOne; } public void setAnyOne(Element value) { this.anyOne = value; } public Element getAnyTwo() { return anyTwo; } public void setAnyTwo(Element value) { this.anyTwo = value; } } When I unmashaller this object by using getAnyOne,I get the contents of the second element. I got null by using getAnyTwo. It is a bug? Anybody can help me ?

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  • Declare two classes from eachother.

    - by tumba25
    I'm writing a app in NetBeans. I have two classes MyApp_View and MyApp_Functions. The MyApp_View class starts like this public class MyApp_View extends FrameView { MyApp_Functions My_functions = new MyApp_Functions(); public MyApp_View(SingleFrameApplication app) { super(app); In MyApp_Functions I have MyApp_View my_view = new MyApp_View(null); I want to access the public variables in MyApp_View from MyApp_Functions and the public methods in functions from view, but have no success with this. Is this doable? And how?

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  • How would I set up this enum to return the image I want?

    - by Justen
    I'm trying to set up this enum so that it has the ability to return the correct image, though I'm struggling with a way to incorporate the context since it is in a separate class. public enum CubeType { GREEN { public Drawable getImage() { return Context.getResources().getDrawable( R.drawable.cube_green ); } }; abstract public Drawable getImage(); } The error I'm getting is: Cannot make a static reference to the non-static method getResources() from the type Context

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  • How to call a service operation at a REST style WCF endpoint uri?

    - by Dieter Domanski
    Hi, is it possible to call a service operation at a wcf endpoint uri with a self hosted service? I want to call some default service operation when the client enters the endpoint uri of the service. In the following sample these uris correctly call the declared operations (SayHello, SayHi): - http://localhost:4711/clerk/hello - http://localhost:4711/clerk/hi But the uri - http://localhost:4711/clerk does not call the declared SayWelcome operation. Instead it leads to the well known 'Metadata publishing disabled' page. Enabling mex does not help, in this case the mex page is shown at the endpoint uri. private void StartSampleServiceHost() { ServiceHost serviceHost = new ServiceHost(typeof(Clerk), new Uri( "http://localhost:4711/clerk/")); ServiceEndpoint endpoint = serviceHost.AddServiceEndpoint(typeof(IClerk), new WebHttpBinding(), ""); endpoint.Behaviors.Add(new WebHttpBehavior()); serviceHost.Open(); } [ServiceContract] public interface IClerk { [OperationContract, WebGet(UriTemplate = "")] Stream SayWelcome(); [OperationContract, WebGet(UriTemplate = "/hello/")] Stream SayHello(); [OperationContract, WebGet(UriTemplate = "/hi/")] Stream SayHi(); } public class Clerk : IClerk { public Stream SayWelcome() { return Say("welcome"); } public Stream SayHello() { return Say("hello"); } public Stream SayHi() { return Say("hi"); } private Stream Say(string what) { string page = @"<html><body>" + what + "</body></html>"; return new MemoryStream(Encoding.UTF8.GetBytes(page)); } } Is there any way to disable the mex handling and to enable a declared operation instead? Thanks in advance, Dieter

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  • How can you write a function that accepts multiple types?

    - by matthy
    I have a function that should work on int[] and on String[] now i have made the same function with a int parameter and an String parameter however if it has to go this way its a bit copy paste work and doesn't look very organized is there a way to solve this and put these 4 functions in 2? static public void print(String s) { System.out.println(s); } static public void print(int s) { System.out.println(s); } static public void printArray(String[] s) { for (int i=0; i<s.length; i++) print(s[i]); } static public void printArray(int[] s) { for (int i=0; i<s.length; i++) print(s[i]); } Thanks Matthy

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  • Why does a looser specification in an overriding method compile after the exception specification fo

    - by Everyone
    The code below has an overridden method with a looser exception specification as compared to the method being overridden. //AnotherMain.java public class AnotherMain { public void dummyMethod( String args[] ) throws IOException{ throw new IOException(); } } //SubAnotherMain.java public class SubAnotherMain extends AnotherMain{ @Override public void dummyMethod( String[] args ) throws Exception { // To get this to compile, change the above - throws IOException, Exception super.dummyMethod(args); throw new Exception("This will not compile unless the exception specification has IOException too"); } } Afaik, the overriding method should not compile at all as the looser specification might break substitutability. Why does it compile after the original exception specification is included in the override? What have I misunderstood?

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  • Missing backslashes in filename using C#

    - by CL4NCY
    Hi, I have a string literal as follows: string filename = @"C:\myfolder\myfile.jpg"; When I use File.Exists(filename) it works most of the time but sometimes I get an error saying the following file doesn't exist: C:myfoldermyfile.jpg Something seems to strip the backslashes out of the filename. This code is sometimes accessed via an ajax request. Does anyone know why/how this could be happening? Edit: Here is a more detailed version of the code. public class Feeds { public static string ftpDir = @"C:\website\Feeds\"; } public class Feed { public static void run(string name) { if (!Directory.Exists(Feeds.ftpDir + name)){ Response.Write("Feed doesn't exist '" + Feeds.ftpDir + name + "'"); return; } //run feed... } }

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  • Java multiple class compositing and boiler plate reduction

    - by h2g2java
    We all know why Java does/should not have multiple inheritance. So this is not questioning about what has already been debated till-cows-come-home. This discusses what we would do when we wish to create a class that has the characteristics of two or more other classes. Probably, most of us would do this to "inherit" from three classes. For simplicity, I left out the constructor.: class Car extends Vehicle { final public Transport transport; final public Machine machine; } So that, Car class directly inherits methods and objects of Vehicle class, but would have to refer to transport and machine explicitly to refer to objects instantiated in Transport and Machine. Car car = new Car(); car.drive(); // from Vehicle car.transport.isAmphibious(); // from Transport car.machine.getCO2Footprint(); // from Machine I thought this was a good idea until when I encounter frameworks that require setter and getter methods. For example, the XML <Car amphibious='false' footPrint='1000' model='Fordstatic999'/> would look for the methods setAmphibious(..), setFootPrint(..) and setModel(..). Therefore, I have to project the methods from Transport and Machine classes class Car extends Vehicle { final public Transport transport; final public Machine machine; public void setAmphibious(boolean b){ this.transport.setAmphibious(b); } public void setFootPrint(String fp){ this.machine.setFootPrint(fp); } } This is OK, if there were just a few characteristics. Right now, I am trying to adapt all of SmartGWT into GWT UIBinder, especially those classes that are not a GWT widget. There are lots of characteristics to project. Wouldn't it be nice if there exists some form of annotation framework that is like this: class Car extends Vehicle @projects {Transport @projects{Machine @projects Guzzler}} { /* No need to explicitly instantiate Transport, Machine or Guzzler */ .... } Where, in case of common names of characteristics exist, the characteristics of Machine would take precedence Guzzler's, and Transport's would have precedence over Machine's, and Vehicle's would have precedence over Transport's. The annotation framework would then instantiate Transport, Machine and Guzzler as hidden members of Car and expand to break-out the protected/public characteristics, in the precedence dictated by the @project annotation sequence, into actual source code or into byte-code. Preferably into byte-code. So that the setFootPrint method is found in both Machine and Guzzler, only that of Machine's would be projected. Questions: Don't you think this is a good idea to have such a framework? Does such a framework already exist? Tell me where/what. Is there an eclipse plugin that does it? Is there a proposal or plan anywhere that you know about such an annotation framework? It would be wonderful too, if the annotation/plugin framework lets me specify that boolean, int, or whatever else needs to be converted from String and does the conversion/parsing for me too. Please advise, somebody. I hope wording of my question was clear enough. Thx. Edited: To avoid OO enthusiasts jumping to conclusion, I have renamed the title of this question.

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  • windows phone deserialization json

    - by user2042227
    I have a weird issue. so I am making a few calls in my app to a webservice, which replies with data. However I am using a token based login system, so the first time the user enters the app I get a token from the webservice to login for that specific user and that token returns only that users details. The problem I am having is when the user changes I need to make the calls again, to get the new user's details, but using visual studio's breakpoint debugging, it shows the new user's token making the call however the problem is when the json is getting deserialized, it is as if it still reads the old data and deserializes that, when I exit my app with the new user it works fine, so its as if it is reading cached values, but I have no idea how to clear it? I am sure the new calls are being made and the problem lies with the deserializing, but I have tried clearing the values before deserializing them again, however nothing works. am I missing something with the json deserializer, how van I clear its cached values? here I make the call and set it not to cache so it makes a new call everytime: client.Headers[HttpRequestHeader.CacheControl] = "no-cache"; var token_details = await client.DownloadStringTaskAsync(uri); and here I deserialize the result, it is at this section the old data gets shown, so the raw json being shown inside "token_details" is correct, only once I deserialize the token_details, it shows the wrong data. deserialized = JsonConvert.DeserializeObject(token_details); and the class I am deserializing into is a simple class nothing special happening here, I have even tried making the constructor so that it clears the values each time it gets called. public class test { public string status { get; set; } public string name{ get; set; } public string birthday{ get; set; } public string errorDes{ get; set; } public test() { status = ""; name= ""; birthday= ""; errorDes= ""; } } uri's before making the calls: {https://whatever.co.za/token/?code=BEBCg==&id=WP7&junk=121edcd5-ad4d-4185-bef0-22a4d27f2d0c} - old call "UBCg==" - old reply {https://whatever.co.za/token/?code=ABCg==&id=WP7&junk=56cc2285-a5b8-401e-be21-fec8259de6dd} - new call "UBCg==" - new response which is the same response as old call as you can see i did attach a new GUID everytime i make the call, but then the new uri is read before making the downloadstringtaskasync method call, but it returns with the old data

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  • Using IoC and Dependency Injection, how do I wrap an existing implementation with a new layer of imp

    - by Dividnedium
    I'm trying to figure out how this would be done in practice, so as not to violate the Open Closed principle. Say I have a class called HttpFileDownloader that has one function that takes a url and downloads a file returning the html as a string. This class implements an IFileDownloader interface which just has the one function. So all over my code I have references to the IFileDownloader interface and I have my IoC container returning an instance of HttpFileDownloader whenever an IFileDownloader is Resolved. Then after some use, it becomes clear that occasionally the server is too busy at the time and an exception is thrown. I decide that to get around this, I'm going to auto-retry 3 times if I get an exception, and wait 5 seconds in between each retry. So I create HttpFileDownloaderRetrier which has one function that uses HttpFileDownloader in a for loop with max 3 loops, and a 5 second wait between each loop. So that I can test the "retry" and "wait" abilities of the HttpFileDownloadRetrier I have the HttpFileDownloader dependency injected by having the HttpFileDownloaderRetrier constructor take an IFileDownloader. So now I want all Resolving of IFileDownloader to return the HttpFileDownloaderRetrier. But if I do that, then HttpFileDownloadRetrier's IFileDownloader dependency will get an instance of itself and not of HttpFileDownloader. So I can see that I could create a new interface for HttpFileDownloader called IFileDownloaderNoRetry, and change HttpFileDownloader to implement that. But that means I'm changing HttpFileDownloader, which violates Open Closed. Or I could implement a new interface for HttpFileDownloaderRetrier called IFileDownloaderRetrier, and then change all my other code to refer to that instead of IFileDownloader. But again, I'm now violating Open Closed in all my other code. So what am I missing here? How do I wrap an existing implementation (downloading) with a new layer of implementation (retrying and waiting) without changing existing code? Here's some code if it helps: public interface IFileDownloader { string Download(string url); } public class HttpFileDownloader : IFileDownloader { public string Download(string url) { //Cut for brevity - downloads file here returns as string return html; } } public class HttpFileDownloaderRetrier : IFileDownloader { IFileDownloader fileDownloader; public HttpFileDownloaderRetrier(IFileDownloader fileDownloader) { this.fileDownloader = fileDownloader; } public string Download(string url) { Exception lastException = null; //try 3 shots of pulling a bad URL. And wait 5 seconds after each failed attempt. for (int i = 0; i < 3; i++) { try { fileDownloader.Download(url); } catch (Exception ex) { lastException = ex; } Utilities.WaitForXSeconds(5); } throw lastException; } }

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  • Dependency Property ListBox

    - by developer
    Hi All, I want to use a dependency property, so that my label displays values selected in the listbox. This is just to more clearly understand the working of a dependency property. <Window x:Class="WpfApplication1.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:WPFToolkit="clr-namespace:Microsoft.Windows.Controls;assembly=WPFToolkit" xmlns:local="clr-namespace:WpfApplication1" x:Name="MyWindow" Height="200" Width="300" > <StackPanel> <ListBox x:Name="lbColor" Width="248" Height="56" ItemsSource="{Binding TestColor}"/> <StackPanel> <Label Content="{Binding Path=Test, ElementName=lbColor}" /> </StackPanel> </StackPanel> </Window> Code Behind, namespace WpfApplication1 { /// <summary> /// Interaction logic for Window1.xaml /// </summary> public partial class Window1 : Window { public ObservableCollection<string> TestColor { get; set; } public String Test { get { return (String)GetValue(TestProperty); } set { SetValue(TestProperty, value); } } // Using a DependencyProperty as the backing store for Title. This enables animation, styling, binding, etc... public static readonly DependencyProperty TestProperty = DependencyProperty.Register("Test", typeof(String), typeof(ListBox), new UIPropertyMetadata("Test1")); public Window1() { InitializeComponent(); TestColor = new ObservableCollection<string>(); DataContext = this; TestColor.Add("Red"); TestColor.Add("Orange"); TestColor.Add("Yellow"); TestColor.Add("Green"); TestColor.Add("Blue"); } } } Can anyone explain me how will I accompalish this using a dependency property. Somehow I am very confused with the Dependency Property concept, and I just wanted to see a working example for that.

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  • How does java implement inner class closures?

    - by thecoop
    In Java an anonymous inner class can refer to variables in it's local scope: public class A { public void method() { final int i = 0; doStuff(new Action() { public void doAction() { Console.printf(i); // or whatever } }); } } My question is how is this actually implemented? How does i get to the anonymous inner doAction implementation, and why does it have to be final?

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  • java annotations - problem with calling a locator class from a Vaadin Project

    - by George
    Hello, I'm not sure how to explain this without writing several pages so I hope the actual code is more expressive. I've made a jar containing multiple annotation declaration similar to the following: @Target(ElementType.PACKAGE) @Retention(RetentionPolicy.RUNTIME) public @interface MarkedPackage { } then I have made a test jar containing several classes in several packages and marked just one package with the above annotation (with package-info.java) like below: @myPackage.MarkedPackage package package.test.jar; this jar had in its build path the jar containing the annotations. then I made a static class that has a method (LoadPlugins) that retrieves a list with all the jars of a directory. Then it searches through the jars for the 'package-info' class and checks if that classes package contains the MarkedPackage annotation. by calling this: if (checkPackageAnnotation(thisClass.getPackage())) where thisClass is the package-info class retrieved via a classloader. and: public static boolean checkPackageAnnotation(AnnotatedElement elem) { System.out.println(elem.getAnnotations().length); if (elem == null || !elem.isAnnotationPresent(MarkedPackage.class)) return false; return true; } the elem.getAnnotatios().length is there for debug purposes. And the problem appears when I call the method from the static class: if I call it from a main function: public class MyMain { public static void main(String[] args){ PluginUtils.LoadPlugins(); } } everything works perfectly it displays '1' from that System.out.println(elem.getAnnotations().length); But if I call it from a button from my Vaadin project: header.addComponent(new Button("CallThat", new Button.ClickListener() { public void buttonClick(ClickEvent event) { PluginUtils.LoadPlugins(); } })); It displays '0' from that System.out.println(elem.getAnnotations().length); Also I should mention that I created the main inside my Vaadin project so it would have the exact same build path and resources. Is there a problem with web applications and that "@Retention(RetentionPolicy.RUNTIME)" ? hope I was clear enough... Hope someone has a solution for me... If you need more information - let me know. Thank you.

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  • inheritance and hidden overloads

    - by Caspin
    The following code doesn't compile. struct A {}; struct B {}; class Base { public: virtual void method( A param ) { } virtual void method( B param ) = 0; }; class Derived : public Base { public: //using Base::method; void method( B param ) { } }; int main() { Derived derived; derived.method(A()); } The compiler can't find the overload of method() that has an A parameter. The 'fix' is to add a using declaration in the derived class. My question is why. What is the rational for a weird language rule like this? I verified the error in both GCC and Comeau, so I assume this isn't a compiler bug but a feature of the language. Comeau at least gives me this warning: "ComeauTest.c", line 10: warning: overloaded virtual function "Base::method" is only partially overridden in class "Derived" class Derived : public Base ^

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  • Activator.CreateInstance(string) and Activator.CreateInstance<T>() difference

    - by Juan Manuel Formoso
    No, this is not a question about generics. I have a Factory pattern with several classes with internal constructors (I don't want them being instantiated if not through the factory). My problem is that CreateInstance fails with a "No parameterless constructor defined for this object" error unless I pass "true" on the non-public parameter. Example // Fails Activator.CreateInstance(type); // Works Activator.CreateInstance(type, true); I wanted to make the factory generic to make it a little simpler, like this: public class GenericFactory<T> where T : MyAbstractType { public static T GetInstance() { return Activator.CreateInstance<T>(); } } However, I was unable to find how to pass that "true" parameter for it to accept non-public constructors (internal). Did I miss something or it isn't possible?

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  • Can i override an abstract method written in a parent class, with a different name in a child class?

    - by Ranhiru
    abstract class SettingSaver { public abstract void add(string Name, string Value); public abstract void remove(string SettingName); } class XMLSettings : SettingSaver { public override void add(string Name, string Value) { throw new NotImplementedException(); } public override void remove(string SettingName) { throw new NotImplementedException(); } } Is there anyway that I can change the name of the add function in XMLSettings class to addSetting but make sure it overrides the add function in the SettingSaver? I know it should be definitely overridden in derived classes but just want to know whether I can use a different name :) Thanx in advance :D

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