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  • Registering NUnit DynamicMock Instances in a UnityContainer

    - by Phil
    I'm somewhat new to Unity and dependency injection. I'm trying to write a unit test that goes something like this: [Test] public void Test() { UnityContainer container = new UnityContainer(); DynamicMock myMock = new DynamicMock(typeof(IMyInterface)); container.RegisterInstance(typeof(IMyInterface), myMock.MockInstance); //Error here // Continue unit test... } When this test executes, the container throws an ArgumentNullException inside the RegisterInstance method with the message Value cannot be null. Parameter name: assignmentValueType. The top line of the stack trace is at Microsoft.Practices.Unity.Utility.Guard.TypeIsAssignable(Type assignmentTargetType, Type assignmentValueType, String argumentName). Why can't I register a MockInstance with the UnityContainer, and how do I work around this?

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  • Resolving HttpRequestScoped Instances outside of a HttpRequest in Autofac

    - by Page Brooks
    Suppose I have a dependency that is registered as HttpRequestScoped so there is only one instance per request. How could I resolve a dependency of the same type outside of an HttpRequest? For example: // Global.asax.cs Registration builder.Register(c => new MyDataContext(connString)).As<IDatabase>().HttpRequestScoped(); _containerProvider = new ContainerProvider(builder.Build()); // This event handler gets fired outside of a request // when a cached item is removed from the cache. public void CacheItemRemoved(string k, object v, CacheItemRemovedReason r) { // I'm trying to resolve like so, but this doesn't work... var dataContext = _containerProvider.ApplicationContainer.Resolve<IDatabase>(); // Do stuff with data context. } The above code throws a DependencyResolutionException when it executes the CacheItemRemoved handler: No scope matching the expression 'value(Autofac.Builder.RegistrationBuilder`3+<c__DisplayClass0[MyApp.Core.Data.MyDataContext,Autofac.Builder.SimpleActivatorData,Autofac.Builder.SingleRegistrationStyle]).lifetimeScopeTag.Equals(scope.Tag)' is visible from the scope in which the instance was requested.

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  • How does WAS/IIS manage ServiceHost instances?

    - by foosnazzy
    It appears that WAS will call ServiceHostFactory.CreateHost() once per each service implementation. How does WAS manage the lifetime of the ServiceHost/ServiceHostFactory? We have a custom factory/host that is occasionally being re-initialized. I'm wondering if WAS is recycling itself or it has some other reason to re-create the ServiceHostFactory/ServiceHost. I'm guessing the ServiceHostFactory gets fired up for the AppDomain and is a singleton, can someone confirm?

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  • App Engine webapp.RequestHandler child instances has no self.request during __init__

    - by grucha
    i use modified webapp.RequestHandler for handling requests in my app: class MyRequestHandler(webapp.RequestHandler): """ Request handler with some facilities like user. self.out is the dictionary to pass to templates """ def __init__(self, *args, **kwargs): super(MyRequestHandler, self).__init__(*args, **kwargs) self.out = { 'user': users.get_current_user(), 'logout_url': users.create_logout_url(self.request.uri) } def render(self, template_name): """ Shortcut to render templates """ self.response.out.write(template.render(template_name, self.out)) class DeviceList(MyRequestHandler): def get(self): self.out['devices'] = GPSDevice.all().fetch(1000) self.render('templates/device_list.html') but I get an exception: line 28, in __init__ self.out['logout_url'] = users.create_logout_url(self.request.uri) AttributeError: 'DeviceList' object has no attribute 'request' When the code causing exception is moved out of __init__ everything's fine: class MyRequestHandler(webapp.RequestHandler): """ Request handler with some facilities like user. self.out is the dictionary to pass to templates and initially it contains user object for example """ def __init__(self, *args, **kwargs): super(MyRequestHandler, self).__init__(*args, **kwargs) self.out = { 'user': users.get_current_user(), } def render(self, template_name): """ Shortcut to render templates """ self.out['logout_url'] = users.create_logout_url(self.request.uri) self.response.out.write(template.render(template_name, self.out)) Whi is that? Why there's no self.request after parent's (i.e. webapp.RequestHandler's) __init__ was executed?

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  • Confusion Matrix with number of classified/misclassified instances on it (Python/Matplotlib)

    - by Pinkie
    I am plotting a confusion matrix with matplotlib with the following code: from numpy import * import matplotlib.pyplot as plt from pylab import * conf_arr = [[33,2,0,0,0,0,0,0,0,1,3], [3,31,0,0,0,0,0,0,0,0,0], [0,4,41,0,0,0,0,0,0,0,1], [0,1,0,30,0,6,0,0,0,0,1], [0,0,0,0,38,10,0,0,0,0,0], [0,0,0,3,1,39,0,0,0,0,4], [0,2,2,0,4,1,31,0,0,0,2], [0,1,0,0,0,0,0,36,0,2,0], [0,0,0,0,0,0,1,5,37,5,1], [3,0,0,0,0,0,0,0,0,39,0], [0,0,0,0,0,0,0,0,0,0,38] ] norm_conf = [] for i in conf_arr: a = 0 tmp_arr = [] a = sum(i,0) for j in i: tmp_arr.append(float(j)/float(a)) norm_conf.append(tmp_arr) plt.clf() fig = plt.figure() ax = fig.add_subplot(111) res = ax.imshow(array(norm_conf), cmap=cm.jet, interpolation='nearest') cb = fig.colorbar(res) savefig("confmat.png", format="png") But I want to the confusion matrix to show the numbers on it like this graphic (the right one): http://i48.tinypic.com/2e30kup.jpg How can I plot the conf_arr on the graphic?

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  • Flex wordwrap issue with multiple text instances

    - by Craig Myles
    Hi, I have a scenario where I want to dynamically add words of text to a container so that it forms a paragraph of text which is wrapped neatly according to the size of the parent container. Each text element will have differing formatting, and will have differing user interaction options. For example, imagine the text " has just spoken out about ". Each word will be added to the container one at a time, at run time. The username in this case would be bold, and if clicked on will trigger an event. Same with the news article. The rest of the text is just plain text which, when clicked on, would do nothing. Now, I'm using Flex 3 so I don't have access to the fancy new text formatting tools. I've implemented a solution where the words are plotted onto a canvas, but this means that the words are wrapped at a particular y position (an arbitrary value I've chosen). When the container is resized, the words still wrap at that position which leaves lots of space. I thought about adding each text element to an Array Collection and using this as a datasource for a Tile List, but Tile Lists don't support variable column widths (in my limited knowledge) so each word would use the same amount of space which isn't ideal. Does anyone know how I can plot words onto a container so that I can retain formatting, events and word wrapping at paragraph level, even if the container is resized?

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  • Accessing previous activity instances in a sequence activity

    - by Dan Revell
    This has a rather SharePoint spin to it but the problem is straight workflow. I've got a parallel replication activity which contains a sequence activity. The sequence activity contains a CreateTask activity, a CodeActivity, a OnTaskChanged activity and finally a CompleteTask activity. The idea is to create a task for each username passed into the ReplicatorActivity.InitialChildData property. Typically in workflow I bind a field to the CreateTask.TaskId and CreateTask.TaskProperties and inside the CreateTask.MethodInvoking I set these through the local bound fields. This works and my tasks all get created properly. However in the CodeActivity that follows, I want to then access the TaskProperties. The problem I am encountering is that this field holds the values of the final task to be created as the CreateTask runs for all the replications before the CodeActivity gets to runs. From the CodeActivity, here are two ways I've tried to access the CreateTask activity instance from the same context or instance or whatever the terminology is for the replicated sequence. CreateTask task = ((CreateTask)sender.Parent.GetActivityByName("createSoftwareRequestTask", true)); CreateTask createTask = (CreateTask)sender.Parent.Activities[0]; Unfortunately the CreateTask activities both refer back to the last task to be created and not the task from the context that the CodeActivity is executing within. Two reasons why this might be that I can think of. I'm not accessing the correct instance with my code. I am accessing the correct instance, but as the properties I require were bound to and set through local fields then their previous data was overwritten. I'm hitting a brick wall with my understanding of workflow with this and would very much appreciate some assistance here.

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  • How would you gather client's data on Google App Engine without using Datastore/Backend Instances too much?

    - by ruslan
    I'm relatively new to StackExchange and not sure if it's appropriate place to ask design question. Site gives me a hint "The question you're asking appears subjective and is likely to be closed". Please let me know. Anyway.. One of the projects I'm working on is online survey engine. It's my first big commercial project on Google App Engine. I need your advice on how to collect stats and efficiently record them in DataStore without bankrupting me. Initial requirements are: After user finishes survey client sends list of pairs [ID (int) + PercentHit (double)]. This list shows how close answers of this user match predefined answers of reference answerers (which identified by IDs). I call them "target IDs". Creator of the survey wants to see aggregated % for given IDs for last hour, particular timeframe or from the beginning of the survey. Some surveys may have thousands of target/reference answerers. So I created entity public class HitsStatsDO implements Serializable { @Id transient private Long id; transient private Long version = (long) 0; transient private Long startDate; @Parent transient private Key parent; // fake parent which contains target id @Transient int targetId; private double avgPercent; private long hitCount; } But writing HitsStatsDO for each target from each user would give a lot of data. For instance I had a survey with 3000 targets which was answered by ~4 million people within one week with 300K people taking survey in first day. Even if we assume they were answering it evenly for 24 hours it would give us ~1040 writes/second. Obviously it hits concurrent writes limit of Datastore. I decided I'll collect data for one hour and save that, that's why there are avgPercent and hitCount in HitsStatsDO. GAE instances are stateless so I had to use dynamic backend instance. There I have something like this: // Contains stats for one hour private class Shard { ReadWriteLock lock = new ReentrantReadWriteLock(); Map<Integer, HitsStatsDO> map = new HashMap<Integer, HitsStatsDO>(); // Key is target ID public void saveToDatastore(); public void updateStats(Long startDate, Map<Integer, Double> hits); } and map with shard for current hour and previous hour (which doesn't stay here for long) private HashMap<Long, Shard> shards = new HashMap<Long, Shard>(); // Key is HitsStatsDO.startDate So once per hour I dump Shard for previous hour to Datastore. Plus I have class LifetimeStats which keeps Map<Integer, HitsStatsDO> in memcached where map-key is target ID. Also in my backend shutdown hook method I dump stats for unfinished hour to Datastore. There is only one major issue here - I have only ONE backend instance :) It raises following questions on which I'd like to hear your opinion: Can I do this without using backend instance ? What if one instance is not enough ? How can I split data between multiple dynamic backend instances? It hard because I don't know how many I have because Google creates new one as load increases. I know I can launch exact number of resident backend instances. But how many ? 2, 5, 10 ? What if I have no load at all for a week. Constantly running 10 backend instances is too expensive. What do I do with data from clients while backend instance is dead/restarting? Thank you very much in advance for your thoughts.

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  • Memory leak in Websphere 7 + EJB3, a lot of instances of ClassMapping

    - by user179168
    Hi, sorry for my english, I speak spanish. I recently migrate an application from ejb 2.x to ejb3 (approx. 300 entities), Im using WebSphere 7.0.0.9. After 10 hours of work, the system crash with an OutOfMemoryError. Analyzing the coredump, I see a lot of instance of the org.apache.openjpa.jdbc.meta.ClassMapping class (please see the attached a screenshot). I believe that the culprit is the list of ValueListeners of the Value class, but I'm not sure, and I dont know how to fix this problem. Thanks

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  • Toggling between instances of NiftyPlayer on a page - won't stop playing when hidden on IE

    - by Ashley
    Hi, i've got a page with links to MP3s, when the link is clicked I use javascript to show a small Flash player (NiftyPlayer) under the link. When a different link is clicked, the old player is hidden and the new player is revealed. The player auto-starts when the element is shown, and auto-stops when hidden - in Firefox. In IE it will only auto-start and NOT auto-stop. This is what I would like to solve. This is an example HTML with link and player <a href="Beat The Radar - Misunderstood What You Said.mp3" onclick="toggle_visibility('player662431');return false;" class="mp3caption">Misunderstood What You Said</a> <div id="player662431" class="playerhide"><embed src="http://www.xxx.com/shop/flash/player.swf?file=/mp3/Beat The Radar - Misunderstood What You Said.mp3&as=1" quality="high" bgcolor="#000000" width="161" height="13" name="niftyPlayer662431" align="" type="application/x-shockwave-flash" swLiveConnect="true" pluginspage="http://www.macromedia.com/go/getflashplayer"></embed> Here is the javascript (i've got jquery installed to let me hide all the open players on this page apart from the new one) function toggle_visibility(id) { $('.playerhide').hide(); var e = document.getElementById(id); e.style.display = 'block'; } I think what I need to do is start the player manually with javascript (rather than using the autostart as=1 function in the URL string) There is some javascript that comes with NiftyPlayer to allow this EG niftyplayer('niftyPlayer1').play() there is also a stop method. I need some help with javascript - how do I add this call to play into my toggle_visibility function (it has the same unique ID number added to the name of the player as the ID of the div that's being shown, but I don't know how to pull this ID number out of one thing and put it in another) I also would like to be able to do niftyplayer('niftyPlayer1').stop() to stop the audio of the previously running player. Is it possible to store the current ID number somewhere and call it back when needed? Thanks for the help, i'm a PHP programmer who needs some support with Javascript - I know what I want to achieve, just don't know the commands to do it! Thanks

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  • Delphi TRttiType.GetMethods return zero TRttiMethod instances

    - by conciliator
    I've recently been able to fetch a TRttiType for an interface using TRttiContext.FindType using Robert Loves "GetType"-workaround ("registering" the interface by an explicit call to ctx.GetType, e.g. RType := ctx.GetType(TypeInfo(IMyPrettyLittleInterface));). One logical next step would be to iterate the methods of said interface. Consider program rtti_sb_1; {$APPTYPE CONSOLE} uses SysUtils, Rtti, mynamespace in 'mynamespace.pas'; var ctx: TRttiContext; RType: TRttiType; Method: TRttiMethod; begin ctx := TRttiContext.Create; RType := ctx.GetType(TypeInfo(IMyPrettyLittleInterface)); if RType <> nil then begin for Method in RType.GetMethods do WriteLn(Method.Name); end; ReadLn; end. This time, my mynamespace.pas looks like this: IMyPrettyLittleInterface = interface ['{6F89487E-5BB7-42FC-A760-38DA2329E0C5}'] procedure SomeProcedure; end; Unfortunately, RType.GetMethods returns a zero-length TArray-instance. Are there anyone able to reproduce my troubles? (Note that in my example I've explicitly fetched the TRttiType using TRttiContext.GetType, not the workaround; the introduction is included to warn readers that there might be some unresolved issues regarding rtti and interfaces.) Thanks!

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  • Injecting all registered instances of a type

    - by James L
    I can successfully perform container.ResolveAll<IMyInterface>(), and I get back an Enumerable containing every registered IMyInterface. However, I can't find a way to have these injected into the constructor of my class. I have tried using ResolvedArrayParameter(), but this gives me an empty enumerator. Am I doing something wrong, or could this be a bug in Unity?

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  • How can I gather client's data on Google App Engine without using Datastore/Backend Instances too much?

    - by ruslan
    One of the projects I'm working on is online survey engine. It's my first big commercial project on Google App Engine. I need your advice on how to collect stats and efficiently record them in DataStore without bankrupting me. Initial requirements are: After user finishes survey client sends list of pairs [ID (int) + PercentHit (double)]. This list shows how close answers of this user match predefined answers of reference answerers (which identified by IDs). I call them "target IDs". Creator of the survey wants to see aggregated % for given IDs for last hour, particular timeframe or from the beginning of the survey. Some surveys may have thousands of target/reference answerers. So I created entity public class HitsStatsDO implements Serializable { @Id transient private Long id; transient private Long version = (long) 0; transient private Long startDate; @Parent transient private Key parent; // fake parent which contains target id @Transient int targetId; private double avgPercent; private long hitCount; } But writing HitsStatsDO for each target from each user would give a lot of data. For instance I had a survey with 3000 targets which was answered by ~4 million people within one week with 300K people taking survey in first day. Even if we assume they were answering it evenly for 24 hours it would give us ~1040 writes/second. Obviously it hits concurrent writes limit of Datastore. I decided I'll collect data for one hour and save that, that's why there are avgPercent and hitCount in HitsStatsDO. GAE instances are stateless so I had to use dynamic backend instance. There I have something like this: // Contains stats for one hour private class Shard { ReadWriteLock lock = new ReentrantReadWriteLock(); Map<Integer, HitsStatsDO> map = new HashMap<Integer, HitsStatsDO>(); // Key is target ID public void saveToDatastore(); public void updateStats(Long startDate, Map<Integer, Double> hits); } and map with shard for current hour and previous hour (which doesn't stay here for long) private HashMap<Long, Shard> shards = new HashMap<Long, Shard>(); // Key is HitsStatsDO.startDate So once per hour I dump Shard for previous hour to Datastore. Plus I have class LifetimeStats which keeps Map<Integer, HitsStatsDO> in memcached where map-key is target ID. Also in my backend shutdown hook method I dump stats for unfinished hour to Datastore. There is only one major issue here - I have only ONE backend instance :) It raises following questions on which I'd like to hear your opinion: Can I do this without using backend instance ? What if one instance is not enough ? How can I split data between multiple dynamic backend instances? It hard because I don't know how many I have because Google creates new one as load increases. I know I can launch exact number of resident backend instances. But how many ? 2, 5, 10 ? What if I have no load at all for a week. Constantly running 10 backend instances is too expensive. What do I do with data from clients while backend instance is dead/restarting?

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  • IBOutlet instances are (null) after loading from NIB

    - by Zach
    I am working on an iPhone app and am getting (null) references to IBOutlet fields in my controller. I have a UIViewController subclass that is set as the File's Owner in my XIB. I have a set of UI elements that are wired into the controller. After loading from NIB and attempting to set properties on those UI elements, I find that they are (null). To clarify, some code: ExpandSearchPageController.h: @interface ExpandSearchPageController : UIViewController { IBOutlet UITextView * completeMessageView; } -(void)checkTextField; @property (nonatomic, retain) IBOutlet UITextView * completeMessageView; ExpandSearchPageController.m: @implementation ExpandSearchPageController @synthesize completeMessageView; -(void)checkTextField { NSLog(@"text field: %@",completeMessageView); } ExpandSearchPageController is set as the File's Owner for ExpandSearchPage.xib. ExpandSearchPage.xib's UITextView is wired to the completeMessageView. When I call ExpandSearchPageController * searchExpanderPage = [[ExpandSearchPageController alloc] initWithNibName:@"ExpandSearchPage" bundle:[NSBundle mainBundle]]; [searchExpanderPage checkTextField]; the result is "text field: (null)" Sorry if this is a total newb question, but I guess I'm still a newb at iPhone programming! Thanks in advance!

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  • Passing Derived Class Instances as void* to Generic Callbacks in C++

    - by Matthew Iselin
    This is a bit of an involved problem, so I'll do the best I can to explain what's going on. If I miss something, please tell me so I can clarify. We have a callback system where on one side a module or application provides a "Service" and clients can perform actions with this Service (A very rudimentary IPC, basically). For future reference let's say we have some definitions like so: typedef int (*callback)(void*); // This is NOT in our code, but makes explaining easier. installCallback(string serviceName, callback cb); // Really handled by a proper management system sendMessage(string serviceName, void* arg); // arg = value to pass to callback This works fine for basic types such as structs or builtins. We have an MI structure a bit like this: Device <- Disk <- MyDiskProvider class Disk : public virtual Device class MyDiskProvider : public Disk The provider may be anything from a hardware driver to a bit of glue that handles disk images. The point is that classes inherit Disk. We have a "service" which is to be notified of all new Disks in the system, and this is where things unravel: void diskHandler(void *p) { Disk *pDisk = reinterpret_cast<Disk*>(p); // Uh oh! // Remainder is not important } SomeDiskProvider::initialise() { // Probe hardware, whatever... // Tell the disk system we're here! sendMessage("disk-handler", reinterpret_cast<void*>(this)); // Uh oh! } The problem is, SomeDiskProvider inherits Disk, but the callback handler can't receive that type (as the callback function pointer must be generic). Could RTTI and templates help here? Any suggestions would be greatly appreciated.

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  • Creating many new instances vs reusing them?

    - by Hugo Riley
    I have multiple business entities in VB.NET Windows Forms application. Right now they are instanced on application startup and used when needed. They hold descriptions of business entities and methods for storing and retrieving data. To cut the long story short, they are somewhat heavy objects to construct (they have some internal dictionaries and references to other objects) created and held in one big global variable called "BLogic". Should I refactor this so that each object is created when needed and released when out of scope? Then every event on UI will probably create a few of this objects. Should I strive to minimize creation of new objects or to minimize number of static and global objects? Generally I am trying to minimize the scope of every variable but should I treat this business logic objects specially?

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  • Apply Alloy UI 1.5 datepicker to multiple instances

    - by MyTitle
    I want to create Alloy UI datapickers on multiple form fields: <div id="date_1_wrapper"> <input type="text" class="datepick" id="date_1" /> </div> <div id="date_2_wrapper"> <input type="text" class="datepick" id="date_2" /> </div> Using JQuery I can do it using following code: $('.datepick').each(function(){ $(this).datepicker(); }); But how to achieve same functionality in Alloy UI? For now I use following code, but this code apply DatePickers by ID, not by CSS class in loop: AUI().use( 'aui-datepicker', function(A) { new A.DatePicker ( { calendar: { dateFormat: '%d/%m/%Y' }, trigger: '#date_1' } ).render('#date_1_wrapper'); new A.DatePicker( { calendar: { dateFormat: '%d/%m/% }, trigger: '#date_2' } ).render('#date_2_wrapper'); } ); I think it this code can be used in beginning, but how to deal with input's and div's ID's? (A.all('.datepcik').each(function() {)

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  • [IE 7/8] Loading HTML content in via Javascript nulls my <title> tag in some instances

    - by Simon
    This is an Explorer only problem and the symptoms are: I have links that when clicked will load in HTML chunks (none of which contain html header tags) using javascript. The html chunks are placed in various <div>s around the page, perhaps 3 different places with 3 different chunks brought in via javascript. When these chunks load in the <title> tag of the page gets set to <title></title> for some unknown (to me) reason. I've used the IE developer toolbar to confirm this by inspecting the DOM tree. I have other pages that do similar things but it does not seem to be a problem there.

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  • How to copy generically superclass instances to subclass instances?

    - by gerry
    Hi @all, I have a class hierarchy / inheritance like this: public class A { private String name; // with getters & setters public void doAWithName(){ ... } } public class B extends A { public void doBWithName(){ // a differnt implementation to what I do in class A } } public class C extends B { public void doCWithName(){ // a differnt implementation to what I do in class A and B } } So at one time there is a instance of class A with the initialized field "name". Later I want this instance of A get wrapped into instance of B or C. So the superclasses should be get wrapped with a subclass! How can I make this most efficent with respect to DRY? I've thought about a constructor that does some copying with the getters/setters. But in this case I have to repeat myself - and this doesn't respect anymore to my initial requirement of DRY! So, how can I warp A to B by just initializing B's new fields (with default values) and delegating the rest to a method in A (which knows more than B about which fields of A should be accessed...). In the same way: If A should be wrapped into C only a method in c should init C's 'new' fields, delegate to B's wrap method (which therefore inits B's 'new' fields in C) and at last B delegates to A which copies it's fields to the fields of C). So in the end I have a new instance of C which has the values of A wrapped (and some default init values to the fields which the inheritance hierarchy has added).

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  • awakeFromNib and loadView execute for different instances

    - by Kamchatka
    Hi, I'm trying to understand why: NSLog(@"self = %p", self); in awakeFromNib prints a different value than the same NSLog in viewDidLoad? This isn't a huge problem because I don't need the awakeFromNib but I would like to understand how it works. The code that creates the controller is the following: MyViewController *myViewController = [[MyViewController alloc] initWithNibName:@"MyViewController" bundle:nil]; myViewController.image = tmpImage; [self.navigationController pushViewController:myViewController animated:YES]; [myViewController release]; Thanks for any advices!

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  • Mutual class instances in C++

    - by SepiDev
    Hi guys. What is the issue with this code? Here we have two files: classA.h and classB.h classA.h: #ifndef _class_a_h_ #define _class_a_h_ #include "classB.h" class B; //???? class A { public: A() { ptr_b = new B(); //???? } virtual ~A() { if(ptr_b) delete ptr_b; //???? num_a = 0; } int num_a; B* ptr_b; //???? }; #endif //_class_a_h_ classB.h: #ifndef _class_b_h_ #define _class_b_h_ #include "classA.h" class A; //???? class B { public: B() { ptr_a = new A(); //???? num_b = 0; } virtual ~B() { if(ptr_a) delete ptr_a; //???? } int num_b; A* ptr_a; //???? }; #endif //_class_b_h_ when I try to compile it, the compiler (g++) says: classB.h: In constructor ‘B::B()’: classB.h:12: error: invalid use of incomplete type ‘struct A’ classB.h:6: error: forward declaration of ‘struct A’ classB.h: In destructor ‘virtual B::~B()’: classB.h:16: warning: possible problem detected in invocation of delete operator: classB.h:16: warning: invalid use of incomplete type ‘struct A’ classB.h:6: warning: forward declaration of ‘struct A’ classB.h:16: note: neither the destructor nor the class-specific operator delete will be called, even if they are declared when the class is defined.

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  • methods of metaclasses on class instances.

    - by Stefano Borini
    I was wondering what happens to methods declared on a metaclass. I expected that if you declare a method on a metaclass, it will end up being a classmethod, however, the behavior is different. Example >>> class A(object): ... @classmethod ... def foo(cls): ... print "foo" ... >>> a=A() >>> a.foo() foo >>> A.foo() foo However, if I try to define a metaclass and give it a method foo, it seems to work the same for the class, not for the instance. >>> class Meta(type): ... def foo(self): ... print "foo" ... >>> class A(object): ... __metaclass__=Meta ... def __init__(self): ... print "hello" ... >>> >>> a=A() hello >>> A.foo() foo >>> a.foo() Traceback (most recent call last): File "<stdin>", line 1, in <module> AttributeError: 'A' object has no attribute 'foo' What's going on here exactly ? edit: bumping the question

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