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• Aggregate Pattern and Performance Issues

  - by Mosh

  Hello, I have read about the Aggregate Pattern but I'm confused about something here. The pattern states that all the objects belonging to the aggregate should be accessed via the Aggregate Root, and not directly. And I'm assuming that is the reason why they say you should have a single Repository per Aggregate. But I think this adds a noticeable overhead to the application. For example, in a typical Web-based application, what if I want to get an object belonging to an aggregate (which is NOT the aggregate root)? I'll have to call Repository.GetAggregateRootObject(), which loads the aggregate root and all its child objects, and then iterate through the child objects to find the one I'm looking for. In other words, I'm loading lots of data and throwing them out except the particular object I'm looking for. Is there something I'm missing here? PS: I know some of you may suggest that we can improve performance with Lazy Loading. But that's not what I'm asking here... The aggregate pattern requires that all objects belonging to the aggregate be loaded together, so we can enforce business rules.

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• Convert Form to UserControl

  - by Joe

  I have a 3rd party code library that I'm using; part of this library is a winforms application for editing the configuration files used by this library. I would like to embed their configuration editor app into my application. I have the source code to their library and the configuration editor is (as far as I can tell) a straight forward Winforms app using standard controls. I'm trying to convert the app's main form into a UserControl so that I can host it inside my application which is WPF (WPF's WindowsFormsHost won't host a Form object, I get an exception). I changed the form object to inherit from UserControl instead of Form and fixed all the compiler errors (there weren't many, just property initializations that don't exist on UserControls) but what's happening is my newly converted control is just blank. When I run my test app I don't see any of the controls that make up the original form, just a blank page. Any ideas? I really don't want to have to re-implement their app from scratch, that would suck. Edit: I forgot to mention I'm testing this in a WinForms application, not WPF, to just get the control working before trying to use it from WPF.

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• Hazelcast Distributed Executor Service KeyOwner

  - by János Veres

  I have problem understanding the concept of Hazelcast Distributed Execution. It is said to be able to perform the execution on the owner instance of a specific key. From Documentation: <T> Future<T> submitToKeyOwner(Callable<T> task, Object key) Submits task to owner of the specified key and returns a Future representing that task. Parameters: task - task key - key Returns: a Future representing pending completion of the task I believe that I'm not alone to have a cluster built with multiple maps which might actually use the same key for different purposes, holding different objects (e.g. something along the following setup): IMap<String, ObjectTypeA> firstMap = HazelcastInstance.getMap("firstMap"); IMap<String, ObjectTypeA_AppendixClass> secondMap = HazelcastInstance.getMap("secondMap"); To me it seems quite confusing what documentation says about the owner of a key. My real frustration is that I don't know WHICH - in which map - key does it refer to? The documentation also gives a "demo" of this approach: import com.hazelcast.core.Member; import com.hazelcast.core.Hazelcast; import com.hazelcast.core.IExecutorService; import java.util.concurrent.Callable; import java.util.concurrent.Future; import java.util.Set; import com.hazelcast.config.Config; public void echoOnTheMemberOwningTheKey(String input, Object key) throws Exception { Callable<String> task = new Echo(input); HazelcastInstance hz = Hazelcast.newHazelcastInstance(); IExecutorService executorService = hz.getExecutorService("default"); Future<String> future = executorService.submitToKeyOwner(task, key); String echoResult = future.get(); } Here's a link to the documentation site: Hazelcast MultiHTML Documentation 3.0 - Distributed Execution Did any of you guys figure out in the past what key does it want?

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• jQuery error when aborting an ajax call only in Internet Explorer

  - by Rob Crowell

  When mousing over an image in a jcarousel, my site displays a popup whose contents are loaded via ajax. I'm doing what I thought was fairly straightforward; keeping a handle to the xhrRequest object, and aborting the existing one before making a new request. It works great in all browsers except IE, where I receive an error "Object doesn't support this property or method" Here's the code that is triggering it: function showPopup { // ... code snipped ... // cancel the existing xhr request if (showPopup.xhrRequest != null) { showPopup.xhrRequest.abort(); showPopup.xhrRequest = null; } showPopup.xhrRequest = $.ajax({url: url, type: "GET", success:function(data) { $("#popup-content").html(data); } }); // ... code snipped ... } showPopup.xhrRequest = null; Works great in Firefox and Chrome. I traced the error down to this bit of code in jquery.js inside the ajax function (line 5233 in my copy of jQuery): // Override the abort handler, if we can (IE doesn't allow it, but that's OK) // Opera doesn't fire onreadystatechange at all on abort try { var oldAbort = xhr.abort; xhr.abort = function() { if (xhr ) { oldAbort.call( xhr ); } onreadystatechange( "abort" ); } catch(e) { } The specific error occurs on the oldAbort.call( xhr ) line. Any ideas?

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• Mouse move panning

  - by Rudy

  Hi all, I'm trying to scroll a series of thumbnails horizontally based on the mouseX position. I can get it to scroll but it's very choppy and for some reason it's not reading my start and end numbers so it will stop scrolling. Can anyone point me in the right direction? Thanks. var thumbBounds:Object = new Object(); thumbBounds = thumbContainer.getBounds(this); thumbContainer.addEventListener(MouseEvent.MOUSE_OVER, setScrolling); private function setScrolling(me:MouseEvent):void { thumbContainer.removeEventListener(MouseEvent.MOUSE_OVER, setScrolling); stage.addEventListener(Event.ENTER_FRAME, scrollThumbs); } private function scrollThumbs(e:Event):void { if(mouseX <= thumbBounds.x || mouseX thumbBounds.width || mouseX < thumbBounds.y || mouseX thumbBounds.height) { thumbContainer.addEventListener(MouseEvent.MOUSE_OVER, setScrolling); stage.removeEventListener(Event.ENTER_FRAME, scrollThumbs); } if(thumbContainer.x = 0) { thumbContainer.x = 0; } if(thumbContainer.x <= -842) { thumbContainer.x = -842; } var xdist:Number = new Number(); xdist = mouseX - 382; thumbContainer.x += Math.round(-xdist / 10); }

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• iPhone - Memory Management - Using Leaks tool and getting some bizarre readings.

  - by Robert

  Hey all, putting the finishing touches on a project of mine so I figured I would run through it and see if and where I had any memory leaks. Found and fixed most of them but there are a couple of things regarding the memory leaks and object alloc that I am confused about. 1) There are 2 memory leaks that do not show me as responsible. There are 8 leaks attributed to AudioToolbox with the function being RegisterEmbeddedAudioCodecs(). This accounts for about 1.5 kb of leaks. The other one is detected immediately when the app begins. Core Graphics is responsible with the extra info being open_handle_to_dylib_path. For the audio leak I have looked over my audio code and to me it seems ok. self.musicPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:songFilePath] error:NULL]; [musicPlayer prepareToPlay]; [musicPlayer play] is called later on in a function. 2) Is it normal for there to be a spike in Object Allocation whenever a new view or controller is presented? My total memory usage is very, very low except for whenever I present a view controller. It spikes then immediately goes back down. I am guessing that this is just the phone handling all the information for switching or something. Blegh. Wall of text. Thanks in advance to anyone who helps! =)

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• Help passing reference to class subroutine in Perl.

  - by stephenmm

  I am trying to pass a routine to another subroutine within a Perl module. But when I pass the sub reference the passed in ref no longer has the object data. Maybe its not possible to do it this way. The line I have a question about is the "unless" lines below: sub get_flag_end { my $self = shift; return ( -e "$self->{file}" ); } sub wait_for_end { my $self = shift; my $timeout = shift; my $poll_interval = shift; # Is it even possible to pass the oject subroutine and retain the objects data? #unless ( $self->timeout( $timeout, $poll_interval, $self->get_flag_end ) ) { # does not work unless ( $self->timeout( $timeout, $poll_interval, \&get_flag_end ) ) { # call happens but members are empty die "!!!ERROR!!! Timed out while waiting for wait_for_end: timeout=$timeout, poll_interval=$poll_interval \n"; } } sub timeout { my $self = shift; my $timeout = shift; my $poll_interval = shift; my $test_condition = shift; until ($test_condition->() || $timeout <= 0) { $timeout -= $poll_interval; sleep $poll_interval; } return $timeout > 0; # condition was met before timeout } I know that I could change the "get_flag_end" routine to take the value as an argument to the subroutine but what if there was a bunch of stuff done in "get_flag_end" and I needed more members from the object. I simplified the code a bit to make it a little easier to follow.

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• How do i write this jpql query? java

  - by Nitesh Panchal

  Hello, Say i have 5 tables, tblBlogs tblBlogPosts tblBlogPostComment tblUser tblBlogMember BlogId BlogPostsId BlogPostCommentId UserId BlogMemberId BlogTitle BlogId CommentText FirstName UserId PostTitle BlogPostsId BlogId BlogMemberId Now i want to retrieve only those blogs and posts for which blogMember has actually commented. So in short, how do i write this plain old sql :- Select b.BlogTitle, bp.PostTitle, bpc.CommentText from tblBlogs b Inner join tblBlogPosts bp on b.BlogId = bp.BlogId Inner Join tblBlogPostComment bpc on bp.BlogPostsId = bpc.BlogPostsId Inner Join tblBlogMember bm On bpc.BlogMemberId = bm.BlogMemberId Where bm.UserId = 1; As you can see, everything is Inner join, so only that row will be retrieved for which the user has commented on some post of some blog. So, suppose he has joined 3 blogs whose ids are 1,2,3 (The blogs which user has joined are in tblBlogMembers) but the user has only commented in blog 2 (of say BlogPostId = 1). So that row will be retrieved and 1,3 won't as it is Inner Join. How do i write this kind of query in jpql? In jpql, we can only write simple queries like say :- Select bm.blogId from tblBlogMember Where bm.UserId = objUser; Where objUser is supplied using :- em.find(User.class,1); Thus once we get all blogs(Here blogId represents a blog object) which user has joined, we can loop through and do all fancy things. But i don't want to fall in this looping business and write all this things in my java code. Instead, i want to leave that for database engine to do. So, how do i write the above plain sql into jpql? and what type of object the jpql query will return? because i am only selecting few fields from all table. In which class should i typecast the result to? I think i posted my requirement correctly, if i am not clear please let me know. Thanks in advance :).

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• Ruby on Rails field_for Form Helper Problems

  - by schone

  Hi all, I'm using the field_for form helper with a loop: <% f.fields_for :permissions do |permission_form| %> <tr> <td><%= permission_form.object.security_module.name %><%= permission_form.hidden_field(:security_module_id) %></td> <td><%= permission_form.object.security_module.description %></td> <tr> <% end %> The resulting output of the above code is this: <input id="role_permissions_attributes_0_id" name="role[permissions_attributes][0][id]" type="hidden" value="76" /> <tr> <td>Diary<input id="role_permissions_attributes_0_security_module_id" name="role[permissions_attributes][0][security_module_id]" type="hidden" value="13" /></td> <td>Access to the Diary Module</td> </tr> <!-- next input field then <tr> tag --> The problem with this markup is that the input tag falls outside of the tr tag which there for causes validation issues with XHTML. Does anyone know how I can have the input tag fall inside the tr tag therefore giving me valid XHTML 1.0 STRICT markup? Thanks

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• Is it possible to use boost::bind to effectively concatenate functions?

  - by Catskul

  Assume that I have a boost::function of with an arbitrary signature called type CallbackType. Is it possible to use boost::bind to compose a function that takes the same arguments as the CallbackType but calls the two functors in succession? Hypothetical example using a magic template: Template<typename CallbackType> class MyClass { public: CallbackType doBoth; MyClass( CallbackType callback ) { doBoth = bind( magic<CallbackType>, protect( bind(&MyClass::alert, this) ), protect( callback ) ); } void alert() { cout << "It has been called\n"; } }; void doIt( int a, int b, int c) { cout << "Doing it!" << a << b << c << "\n"; } int main() { typedef boost::function<void (int, int, int)> CallbackType; MyClass<CallbackType> object( boost::bind(doIt) ); object.doBoth(); return 0; }

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• Creating a custom Configuration

  - by Rob

  I created a customer configuration class Reports. I then created another class called "ReportsCollection". When I try and do the "ConfigurationManager.GetSection()", it doesn't populate my collection variable. Can anyone see any mistakes in my code? Here is the collection class: public class ReportsCollection : ConfigurationElementCollection { public ReportsCollection() { } protected override ConfigurationElement CreateNewElement() { throw new NotImplementedException(); } protected override ConfigurationElement CreateNewElement(string elementName) { return base.CreateNewElement(elementName); } protected override object GetElementKey(ConfigurationElement element) { throw new NotImplementedException(); } public Report this[int index] { get { return (Report)BaseGet(index); } } } Here is the reports class: public class Report : ConfigurationSection { [ConfigurationProperty("reportName", IsRequired = true)] public string ReportName { get { return (string)this["reportName"]; } //set { this["reportName"] = value; } } [ConfigurationProperty("storedProcedures", IsRequired = true)] public StoredProceduresCollection StoredProcedures { get { return (StoredProceduresCollection)this["storedProcedures"]; } } [ConfigurationProperty("parameters", IsRequired = false)] public ParametersCollection Parameters { get { return (ParametersCollection)this["parameters"]; } } [ConfigurationProperty("saveLocation", IsRequired = true)] public string SaveLocation { get { return (string)this["saveLocation"]; } } [ConfigurationProperty("recipients", IsRequired = true)] public RecipientsCollection Recipients { get { return (RecipientsCollection)this["recipients"]; } } } public class StoredProcedure : ConfigurationElement { [ConfigurationProperty("storedProcedureName", IsRequired = true)] public string StoredProcedureName { get { return (string)this["storedProcedureName"]; } } } public class StoredProceduresCollection : ConfigurationElementCollection { protected override ConfigurationElement CreateNewElement() { throw new NotImplementedException(); } protected override ConfigurationElement CreateNewElement(string elementName) { return base.CreateNewElement(elementName); } protected override object GetElementKey(ConfigurationElement element) { throw new NotImplementedException(); } public StoredProcedure this[int index] { get { return (StoredProcedure)base.BaseGet(index); } } } } And here is the very straight-forward code to create the variable: ReportsCollection reportsCollection = (ReportsCollection) System.Configuration.ConfigurationManager.GetSection("ReportGroup");

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• WCF service with PHP client - complex type as parameter not working

  - by Matt F

  Hi, I have a WCF service with three methods. Two of the methods return custom types (these work as expected), and the third method takes a custom type as a parameter and returns a boolean. When calling the third method via a PHP soap client it returns an 'Object reference not set to an instance of an object' exception. Example Custom Type: _ Public Class MyClass Private _propertyA As Double <DataMember()> _ Public Property PropertyA() As Double Get Return _propertyA End Get Set(ByVal value As Double) _propertyA = value End Set End Property Private _propertyB As Double <DataMember()> _ Public Property PropertyB() As Double Get Return _propertyB End Get Set(ByVal value As Double) _propertyB = value End Set End Property Private _propertyC As Date <DataMember()> _ Public Property PropertyC() As Date Get Return _propertyC End Get Set(ByVal value As Date) _propertyC = value End Set End Property End Class Method: Public Function Add(ByVal param As MyClass) As Boolean Implements IService1.Add ' ... End Function PHP client call: $client-Add(array('param'=array( 'PropertyA' = 1, 'PropertyB' = 2, 'PropertyC' = "2009-01-01" ))); The WCF service works fine with a .Net client but I'm new to PHP and can't get this to work. Is it possible to create an instance of 'MyClass' in PHP. Any help would be appreciated. Note: I'm using PHP 5 (XAMPP 1.7.0 for Windows). Thanks Matt

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• youtube embeded player: change video link with javascript, dinamically

  - by Anthony Koval'

  here is a part of html code (video urls marked with a django-template language variables): <div class="mainPlayer"> <object width="580" height="326"> <param name="movie" value="{{main_video.video_url}}"></param> <param name="allowFullScreen" value="true"></param> <param name="allowscriptaccess" value="always"></param> <embed src="{{main_video.video_url}}" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="580" height="326"></embed> </object> </div> and JS-code (using jQuery 1.4.x) $(document).ready(function(){ ..... $(".activeMovie img").live("click", function(){ video_url = ($(this).parent().find('input').val()); $('.mainPlayer').find('param:eq(0)').val(video_url); $('.mainPlayer').find('embed').attr('src', video_url); }) ... }) such a algorithm works fine in ff 3.6.3, but any luck in chrome4 or opera 10.x., src and value are changed, but youtube player still shows an old video.

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• Use Lambda in Attribute constructor to get method's parameters

  - by Anthony Shaw

  I'm not even sure if this is possible, but I've exhausted all of my ideas trying to figure this out, so I figured I'd send this out to the community and see what you thought. And, if it's not possible, maybe you'd have some ideas as well. I'm trying to make an Attribute class that I can add to a method that would allow me to use a lambda expression to get each parameter of the method public ExampleAttribute : Attribute { public object Value { get; set; } public ExampleAttribute(--something here to make the lambda work--, object value) { Value = value; } } I'd like to be able to something like this below: [Example(x=x.Id, 4)] [Example(x=x.filter, "string value")] public ActionResult Index(int Id, string filter) { return View(); } I understand that I might be completely dreaming with this idea. I'm basically trying to write a model to allow for self-documenting REST API Documentation. In a recent project here at work we wrote a dozen or so services with 5 to 15 methods on each, I figure it's easier to write something to do this, than to hand code a documentation page for each. I would plan to eventually release this as an open-source project once I have it in a place that I feel it's releasable.

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• Weird .net 4.0 exception when running unit tests

  - by vdh_ant

  Hi guys I am receiving the following exception when trying to run my unit tests using .net 4.0 under VS2010 with moq 3.1. Attempt by security transparent method 'SPPD.Backend.DataAccess.Test.Specs_for_Core.When_using_base.Can_create_mapper()' to access security critical method 'Microsoft.VisualStudio.TestTools.UnitTesting.Assert.IsNotNull(System.Object)' failed. Assembly 'SPPD.Backend.DataAccess.Test, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' is marked with the AllowPartiallyTrustedCallersAttribute, and uses the level 2 security transparency model. Level 2 transparency causes all methods in AllowPartiallyTrustedCallers assemblies to become security transparent by default, which may be the cause of this exception. The test I am running is really straight forward and looks something like the following: [TestMethod] public void Can_create_mapper() { this.SetupTest(); var mockMapper = new Moq.Mock<IMapper>().Object; this._Resolver.Setup(x => x.Resolve<IMapper>()).Returns(mockMapper).Verifiable(); var testBaseDa = new TestBaseDa(); var result = testBaseDa.TestCreateMapper<IMapper>(); Assert.IsNotNull(result); //<<< THROWS EXCEPTION HERE Assert.AreSame(mockMapper, result); this._Resolver.Verify(); } I have no idea what this means and I have been looking around and have found very little on the topic. The closest reference I have found is this http://dotnetzip.codeplex.com/Thread/View.aspx?ThreadId=80274 but its not very clear on what they did to fix it... Anyone got any ideas?

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• LotusScript - Setting element in for loop

  - by Kris.Mitchell

  I have an array set up Dim managerList(1 To 50, 1 To 100) As String what I am trying to do, is set the first, second, and third elements in the row managerList(index,1) = tempManagerName managerList(index,2) = tempIdeaNumber managerList(index,3) = 1 But get an error when I try to do that saying that the object variable is not set. I maintain index as an integer, and the value corresponds to a single manager, but I can't seem to manually set the third element. The first and second elements set correctly. On the flip side, I have the following code that will allow for the element to be set, For x=1 To 50 If StrConv(tempManagerName,3) = managerList(x,1) Then found = x For y=3 to 100 If managerList(x,y) = "" Then managerList(x,y) = tempIdeaNumber Exit for End If Next Exit For End If Next It spins through the array (laterally) trying to find an empty element. Ideally I would like to set the index of the element the y variable is on into the 3rd element in the row, to keep a count of how many ideas are on the row. What is the best way to keep a count like this? Any idea why I am getting a Object variable not set error when I try to manually set the element?

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• How do I unit test controllers for an asp.net mvc site that uses StructureMap and NHibernate?

  - by Jim Geurts

  I have an asp.net mvc2 application that is using StructureMap 2.6 and NHibernate 3.x. I would like to add unit tests to the application but am sort of at a loss for how to accomplish it. Say I have a basic controller called Posts that has an action called Index. The controller looks something like: public class PostsController : Controller { private readonly IPostService _postService; public PostsController(IPostService postService) { _postService = postService; } public ActionResult Index() { return View(_postService.QueryOver<Post>().Future()); } } If I wanted to create an nunit test that would verify that the index action is returning all of the posts, how do I go about that? If mocking is recommended, do you just assume that interaction with the database will work? Sorry for asking such a broad question, but my web searches haven't turned up anything decent for how to unit test asp.net mvc actions that use StructureMap (or any other IOC) and NHibernate. btw, if you don't like that I return a QueryOver object from my post service, pretend it is an IQueryable object. I'm using it essentially in the same way.

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• Modeling multiple polymorphic relationships using Hibernate

  - by f-potter

  Ruby on Rails has polymorphic relations which are really useful for implementing functionality such as commenting, tagging and rating to name a few. We can have a comment, tag or rating class which has a many to one polymorphic relationship with a commentable, taggable and rateable object. Also, a given domain object can choose to implement any combination of such relations. So, it can for example be commentable, taggable and rateable at the same time. I couldn't think up of a straightforward way to duplicate this functionality in Hibernate. Ideally, there would be a Comment class which will have a many to one relationship with a Commentable class and a Commentable class will conversely have a one to many relationship with Comments. It will be ideal if the concrete domain classes can inherit from a number of such classes, say Commentable and Taggable. Things seem a little complicated as a Java class can only extend one other class and some code might end up being duplicated across a number of classes. I wanted to know what are the best practices for modeling such relationships neatly and concisely using Hibernate?

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• Missing Intellisense While Describing Custom Control Properties Declaratively

  - by Albert Bori

  So, I've been working on this project for a few days now, and have been unable to resolve the issue of getting intellisense support for my custom-defined inner properties for a user control (ascx, mind you). I have seen the solution to this (using server controls, .cs mind you) many times. Spelled out in this article very well. Everything works for me while using ascx controls except intellisense. Here's the outline of my code: [PersistChildren(true)] [ParseChildren(typeof(BreadCrumbItem))] [ControlBuilder(typeof(BreadCrumbItem))] public partial class styledcontrols_buttons_BreadCrumb : System.Web.UI.UserControl { ... [PersistenceMode(PersistenceMode.InnerDefaultProperty)] public List<BreadCrumbItem> BreadCrumbItems { get { return _breadCrumbItems; } set { _breadCrumbItems = value; } } ... protected override void AddParsedSubObject(object obj) { base.AddParsedSubObject(obj); if (obj is BreadCrumbItem) BreadCrumbItems.Add(obj as BreadCrumbItem); } ... public class BreadCrumbItem : ControlBuilder { public string Text { get; set; } public string NavigateURL { get; set; } public override Type GetChildControlType(string tagName, System.Collections.IDictionary attribs) { if (String.Compare(tagName, "BreadCrumbItem", true) == 0) { return typeof(BreadCrumbItem); } return null; } } } Here's my mark up (which works fine, just no intellisense on the child object declarations): <%@ Register src="../styledcontrols/buttons/BreadCrumb.ascx" tagname="BreadCrumb" tagprefix="uc1" %> ... <uc1:BreadCrumb ID="BreadCrumb1" runat="server" BreadCrumbTitleText="Current Page"> <BreadCrumbItem Text="Home Page" NavigateURL="~/test/breadcrumbtest.aspx?iwentsomewhere=1" /> <BreadCrumbItem Text="Secondary Page" NavigateURL="~/test/breadcrumbtest.aspx?iwentsomewhere=1" /> </uc1:BreadCrumb> I think the issue lies with how the intellisense engine traverses supporting classes. All the working examples I see of this are not ascx, but Web Server Controls (cs, in a compiled assembly). If anyone could shed some light on how to accomplish this with ascx controls, I'd appreciate it.

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• Thread safe lazy contruction of a singleton in C++

  - by pauldoo

  Is there a way to implement a singleton object in C++ that is: Lazily constructed in a thread safe manner (two threads might simultaneously be the first user of the singleton - it should still only be constructed once). Doesn't rely on static variables being constructed beforehand (so the singleton object is itself safe to use during the construction of static variables). (I don't know my C++ well enough, but is it the case that integral and constant static variables are initialized before any code is executed (ie, even before static constructors are executed - their values may already be "initialized" in the program image)? If so - perhaps this can be exploited to implement a singleton mutex - which can in turn be used to guard the creation of the real singleton..) Excellent, it seems that I have a couple of good answers now (shame I can't mark 2 or 3 as being the answer). There appears to be two broad solutions: Use static initialisation (as opposed to dynamic initialisation) of a POD static varible, and implementing my own mutex with that using the builtin atomic instructions. This was the type of solution I was hinting at in my question, and I believe I knew already. Use some other library function like pthread_once or boost::call_once. These I certainly didn't know about - and am very grateful for the answers posted.

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• ASP.NET MVC Creating a impersonated user.

  - by Malcolm

  Hi, I have a MVC app where I have a User class and the user can also impersonate another user(Admin users only). So I have this code below that authenticates the request and instantiates my version of a User class. It then tries to get the impersonated user from the Session object but Session is not available in this method in the global.asax. Hope this makes sense. How else could I do this? protected void Application_OnAuthenticateRequest(object sender, EventArgs e) { IMylesterService service = ObjectFactory.GetInstance(); if (Context.User != null) { if (Context.User.Identity.IsAuthenticated) { User user = service.GetUser(Context.User.Identity.Name); if (user == null) throw new ApplicationException("Context.user.Identity.name is not a recognized user"); User impersonatedUser = (User)this.Session["ImpersonatedUser"]; if (impersonatedUser == null) user.ImpersonatedUser = user; else user.ImpersonatedUser = impersonatedUser; System.Threading.Thread.CurrentPrincipal = Context.User = user; return; } } User guest = service.GetGuestUser(); guest.ImpersonatedUser = guest; System.Threading.Thread.CurrentPrincipal = Context.User = guest; }

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• Avoiding null point exception in el in JSF

  - by Buddhika Ariyaratne

  I am developing a JSF application with JPA(EclipseLink 2.0) and Primefaces. I want to know is there any way to avoid null point exception when el calls a property of a null object. I have described the situation. I have Bill class. There may be no or more BillItem objects with a Bill objects. Each BillItem object have Objects like Make, Country, Manufacturer, etc objects. I am displaying several properties of a bill within a single JSF file like this. "#{billControlled.bill.billItem.modal.name}" But if a bill is not selected, or when there are no bill items for a selected bill, the properties accessing in the el are null. I can avoid this by creating new objects for every bill, for example, new make for a new bill item, etc or by creating new properties in the controller itself for all the properties. But that is a very long way and feel like rudimentory. Is there any good practice to avoid this null point exception in el in JSF?

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• Problem with looping a video in Flash

  - by Blaze

  I am trying to loop a video and i am having some issues with this in flash. You can view the video here: http://www.healthcarepros.net/travel.html Here the specific code for the flash video: <script language="javascript"> if (AC_FL_RunContent == 0) { alert("This page requires AC_RunActiveContent.js."); } else { AC_FL_RunContent( 'codebase', 'http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=9,0,0,0', 'width', '330', 'height', '245', 'src', 'healthcare-video', 'quality', 'high', 'pluginspage', 'http://www.macromedia.com/go/getflashplayer', 'align', 'middle', 'play', 'true', 'loop', 'true', 'scale', 'showall', 'wmode', 'window', 'devicefont', 'false', 'id', 'healthcare-video', 'bgcolor', '#ffffff', 'name', 'healthcare-video', 'menu', 'true', 'allowFullScreen', 'false', 'allowScriptAccess','sameDomain', 'movie', 'healthcare-video', 'salign', '' ); //end AC code } </script> <noscript> <object classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000" codebase="http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=9,0,0,0" width="330" height="245" id="healthcare-video" align="middle"> <param name="allowScriptAccess" value="sameDomain" /> <param name="allowFullScreen" value="false" /> <param name="loop" value="true" /> <param name="play" value="true" /> <param name="movie" value="healthcare-video.swf" /><param name="quality" value="high" /><param name="bgcolor" value="#ffffff" /> <embed src="healthcare-video.swf" play="true" flashvars="autoplay=true&play=true" quality="high" bgcolor="#ffffff" width="330" height="245" name="healthcare-video" align="middle" allowScriptAccess="sameDomain" allowFullScreen="false" type="application/x-shockwave-flash" pluginspage="http://www.macromedia.com/go/getflashplayer" /> </object> Additionally, i have added in the parameter code that calls the loop function but for some reason it still doesnt seem to work, any suggestions?

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• stuck with enable session state

  - by Shrewd Demon

  hi i have an application wherein i am accessing the Session object in the CommonCode.cs file that resides in the App_Code folder. But when the session object is accessed the application throws me an error: Session state can only be used when enableSessionState is set to true, either in a configuration file or in the Page directive. Please also make sure that System.Web.SessionStateModule or a custom session state module is included in the \\ section in the application configuration. Now i have already enabled the session state property in the web.config file, here is my code from the web.config file: <pages enableSessionState="true" autoEventWireup="true"> <controls> <add tagPrefix="asp" namespace="System.Web.UI" assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/> <add tagPrefix="asp" namespace="System.Web.UI.WebControls" assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/> </controls> </pages> I dont understand why am i still getting that error !! please help ! thanks a lot.

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• desing pattern for related inputs

  - by curiousMo

  My question is a design question : let's say i have a data entry web page with 4 drop down lists, each depending on the previous one, and a bunch of text boxes. country (ddl), state (ddl), city (ddl), boro (ddl), address (txtBox), zipcode(txtbox). and an object that represents a datarow with a value for each. naturally the country, state, city and boro values will be values of primary keys of some lookup tables. when the user chooses to edits that record, i would load it from database and load it into the page. the issue that I have is how to streamline loading the ddls. i have some code that would grab the object, look thru its values and move them to their corresponding input controls in one shot. but in this case i will have to load possible values of country, then assign values, then load values of state, then assign value ans so on. I guess i am looking for an elegant solution. i am using asp.net, but i think it is irrelevant to the question. i am looking more into a design pattern. thanks

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