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  • How to instanciate a class when its property members are not of primitive types?

    - by Richard77
    Hello, 1) Let's say I've a class MyDataInfo public class MyDataInfo { public int MyDataInfoID { get; set; } public string Name { get; set; } } For the purpose of the fuctionality I'm after, I've created another class (MyData) whose property members are of MyDataInfo type. 2) Here's myData public class MyData { public MyDataInfo Prop1 { get; set; } public MyDataInfo Prop2 { get; set; } } 3) And, here's my action method public ActionResult MyAction() { MyData myObject = new MyData(); return View(myObject); } 4) Finally, this in my View template (which is strongly typed and inherits from MyData) <% = Html.Encode (Model.Prop1.Name)%> <% = Html.Encode (Model.Prop2.Name)%> Unfortunately, I got an error "Object not set to an instance of an object." Am I missing something or is there a different way of obtaining the same result? Thanks for helping

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  • Objective-C: Protocols

    - by Stu
    I'd like an instance variable object to adopt a protocol. @interface GameScene : Scene <AVAudioPlayerDelegate> { @private Layer *content <CocosNodeOpacity>; } For example I'd like my Layer object to adopt the <CocosNodeOpacity> so that I can get the methods -(GLubyte) opacity; //and -(void) setOpacity: (GLubyte) opacity; for free. The syntax shown above is invalid. Is it possible to achieve this without creating a new implementation file and creating a custom object? Thanks.

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  • C++/CLI com-Interop: Exposing a reference type property to VBA

    - by Adam
    After long hours of investigation on exposing C# property that accepts a reference type to VBA, I concluded that it was not possible. In brief, a C# property that is of type double[] or even an object cannot be consumed in VBA like this: ' Compile Error: Function or interface marked as restricted, ' or the function uses an Automation type not supported in Visual Basic oComExposedEarlyBinding.ObjectArray = VBArray ' Run-time error 424: Object required oComExposedEarlyBinding.PlainObject = VBArray Or for more details: C# property exposed to VBA (COM) : Run-time error '424': Object required I would like to know if C++/CLI would support such an option? i.e. Allowing a reference-type property to be exposed to VBA so that a syntax like the above is valid. N.B. You can achieve this by using late binding, but losing the intellisense is not an option.

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  • In django models, how to make all table names not have the app label?

    - by Luigi
    I have a database that was already being used by other applications before i began writing a web interface with django for it. The table names follow simple naming standards, so the django model Customer should map to the table "customer" in the db. At the same time I'm adding new tables/models. Since I find it cumbersome to use app_customer every time i have to write a query (django's ORM is definitely not enough for them) in the other applications and I don't want to rename the existing tables, what is the best way to make all models in my django app use tables without applabel_, besides adding a Meta class with db_table= to each model? Is there any reason why I shouldn't do this? I have only one web app that needs to access this db, everything else doesn't use django models.

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  • Adding row to DataGridView from Thread

    - by she hates me
    Hello, I would like to add rows to DataGridView from two seperate threads. I tried something with delegates and BeginInvoke but doesn't work. Here is my row updater function which is called from another function in a thread. public delegate void GRIDLOGDelegate(string ulke, string url, string ip = ""); private void GRIDLOG(string ulke, string url, string ip = "") { if (this.InvokeRequired) { // Pass the same function to BeginInvoke, // but the call would come on the correct // thread and InvokeRequired will be false. object[] myArray = new object[3]; myArray[0] = ulke; myArray[1] = url; myArray[2] = ip; this.BeginInvoke(new GRIDLOGDelegate(GRIDLOG), new object[] { myArray }); return; } //Yeni bir satir daha olustur string[] newRow = new string[] { ulke, url, ip }; dgLogGrid.Rows.Add(newRow); }

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  • Binding command to button in silverlight 4 using mvvm

    - by Archie
    Hello, I have a user control called HomePage.xaml. I'm creating a model instance (using MVVM pattern) in the code behind file in the constructor of page as MainViewModel model = new MainViewModel(); I have a button in HomePage.xaml which I want to bind to the command inside MainViewModel called GetData() and want to populate the data in datagrid. MainViewModel has an ObservableCollection which I would use to bind the data in datagrid. Populating the data in datagrid without binding command works fine. I'm binding the button as: <StackPanel x:Name="stkPanelInput" Orientation="Horizontal" VerticalAlignment="Center" HorizontalAlignment="Center"> <Button x:Name="buttonGetData" Width="70" Content="GetData" Command="{Binding GetData}" Click="buttonGetData_Click"/> </StackPanel> How shall I bind the command using MVVM? Thanks.

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  • nested form & habtm

    - by brewster
    so i am trying to save to a join table in a habtm relationship, but i am having problems. from my view, i pass in a group id with: = link_to "Create New User", new_user_url(:group => 1) User model (user.rb) class User < ActiveRecord::Base has_and_belongs_to_many :user_groups accepts_nested_attributes_for :user_groups end UserGroups model (user_groups.rb) class UserGroup < ActiveRecord::Base has_and_belongs_to_many :users end users_controller.rb def new @user = User.new(:user_group_ids => params[:group]) end in the new user view, i have access to the User.user_groups object, however when i submit the form, not only does it not save into my join table (user_groups_users), but the object is no longer there. all the other objects & attributes of my User object are persistent except for the user group. i just started learning rails, so maybe i am missing something conceptually here, but i have been really struggling with this.

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  • Why aren't these shared_ptrs pointing to the same container?

    - by BeeBand
    I have a class Model: class Model { ... boost::shared_ptr<Deck> _deck; boost::shared_ptr<CardStack> _stack[22]; }; Deck inherits from CardStack. I tried to make _stack[0] point to the same thing that _deck points to by going: { _deck = boost::shared_ptr<Deck>(new Deck()); _stack[0] = _deck; } It seems that the assignment to _deck of _stack[0] results in a copy of _deck being made. How can I get them to point to the same thing?

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  • ToolStripComboBox + objects default string value

    - by Martin
    I am using a ToolStripComboBox to list some data. I am populating this combo with some custom objects: For Each obj As myObject In myObjectList myToolStripComboBox.Items.Add(obj) Next This works great except the text displayed in the combo is the name of the object class. I can understand why and realise that I need to do something to make the combo use a property from my class instead. The help files state: To add objects to the list at run time, assign an array of object references with the AddRange method. The list then displays the default string value for each object. You can add individual objects with the Add method. The bit in bold suggests I need to setup the default string value in my class. How would I go about doing this?

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  • Why is django admin not accepting Nullable foreign keys?

    - by p.g.l.hall
    Here is a simplified version of one of my models: class ImportRule(models.Model): feed = models.ForeignKey(Feed) name = models.CharField(max_length=255) feed_provider_category = models.ForeignKey(FeedProviderCategory, null=True) target_subcategories = models.ManyToManyField(Subcategory) This class manages a rule for importing a list of items from a feed into the database. The admin system won't let me add an ImportRule without selecting a feed_provider_category despite it being declared in the model as nullable. The database (SQLite at the moment) even checks out ok: >>> .schema ... CREATE TABLE "someapp_importrule" ( "id" integer NOT NULL PRIMARY KEY, "feed_id" integer NOT NULL REFERENCES "someapp_feed" ("id"), "name" varchar(255) NOT NULL, "feed_provider_category_id" integer REFERENCES "someapp_feedprovidercategory" ("id"), ); ... I can create the object in the python shell easily enough: f = Feed.objects.get(pk=1) i = ImportRule(name='test', feed=f) i.save() ...but the admin system won't let me edit it, of course. How can I get the admin to let me edit/create objects without specifying that foreign key?

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  • Localized tables and Entity Framework

    - by Pyttroll
    Hi all, I have a scenario where I need to localized values of objects in my database. Let's say you have an application that can create animals, if the user is english the value of the "Name" property of an animal would be entered as "Cat" in the UI whereas it would be entered as "Chat" in french. The animal culture table would contain 2 records pointing to the same animal in the parent table. When reading values back, if the value of "Name" does not exist in the user culture the default value (value the object was originally created with) would be used. The following diagrams demonstrate how the data is stored in SQL: I'm trying to map this schema to an object model using the Entity Framework, I'm a bit confused as to what the best way to approach the problem. Is EF appropriate for this? Should I used EF4? This EF model will be used by .NET RIA Services. Thanks, Pierre-Yves Troel Ayuda Media Systems http://www.ayudasystems.com

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  • Observing an NSMutableArray for insertion/removal

    - by Adam Ernst
    A class has a property (and instance var) of type NSMutableArray with synthesized accessors (via @property). If you observe this array using: [myObj addObserver:self forKeyPath:@"theArray" options:0 context:NULL]; And then insert an object in the array like this: [[myObj theArray] addObject:[NSString string]]; An observeValueForKeyPath... notification is not sent. However, the following does send the proper notification: [[myObj mutableArrayValueForKey:@"theArray"] addObject:[NSString string]]; This is because mutableArrayValueForKey returns a proxy object that takes care of notifying observers. But shouldn't the synthesized accessors automatically return such a proxy object? What's the proper way to work around this--should I write a custom accessor that just invokes [super mutableArrayValueForKey...]?

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  • How to make flash video show up under navigation element?

    - by Deshiknaves
    I know that the wmode needs to be either transparent or opaque for the video to show up under other elements on the page. I've added the wmode to the element and param in object, I still have no luck with it. <object width="400" height="225"><param name="wmode" value="transparent" /><param name="allowfullscreen" value="true" /><param name="allowscriptaccess" value="always" /><param name="movie" value="http://vimeo.com/moogaloop.swf?clip_id=10875088&amp;server=vimeo.com&amp;show_title=1&amp;show_byline=1&amp;show_portrait=0&amp;color=&amp;fullscreen=1" /><embed src="http://vimeo.com/moogaloop.swf?clip_id=10875088&amp;server=vimeo.com&amp;show_title=1&amp;show_byline=1&amp;show_portrait=0&amp;color=&amp;fullscreen=1" type="application/x-shockwave-flash" allowfullscreen="true" allowscriptaccess="always" width="400" height="225" wmode="transparent"></embed></object><p><a href="http://vimeo.com/10875088">Clutchy Hopkins - Verbal Headlock</a> from <a href="http://vimeo.com/ubiquityrecords">Ubiquity Records</a> on <a href="http://vimeo.com">Vimeo</a>.</p>

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  • Best way to check for null values in Java?

    - by Arty-fishL
    I need to check whether the function of an object returns true or false in Java, but that object may be null, so obviously then the function would throw a NullPointerException. This means I need to check if the object is null before checking the value of the function. What is the best way to go about this? I've listed some methods I considered, I just want to know the most sensible one, the one that is best programming practice for Java (opinion?). // method 1 if (foo != null) { if (foo.bar()) { etc... } } // method 2 if (foo != null ? foo.bar() : false) { etc... } // method 3 try { if (foo.bar()) { etc... } } catch (NullPointerException e) { } // method 4 // would this work all the time, would it still call foo.bar()? if (foo != null && foo.bar()) { etc... }

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  • How do I Moq It.IsAny for an array in the setup of a method?

    - by Graham
    I'm brand new to Moq (using v 4) and am struggling a little with the documentation. What I'm trying to do is to Moq a method that takes a byte array and returns an object. Something like: decoderMock.Setup(d => d.Decode(????).Returns(() => tagMock.Object); The ???? is where the byte[] should be, but I can't work out how to make it so that I don't care what's in the byte array, just return the mocked object I've already set up. Moq.It.IsAny expects a generic. Any help please?

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  • Repository vs Data Access

    - by vdh_ant
    Hi guys In the context of the n-tier application, is there a difference between what you would consider your data access classes to be and your repositories? I tend to think yes but I just wanted to see what other thought. My thinking is that the job of the repository is just to contain and execute the raw query itself, where as the data access class would create the context, execute the repository (passing in the context), handle mapping the data model to the domain model and return the result back up... What do you guys think? Also do you see any of this changing in a Linq to XML scenario (assuming that you change the context for the relevant XDocument)? Cheers Anthony

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  • Grails: Property Null error

    - by richardhell
    I've a domain called Modulo with some properties and a Controller with a method that create a object from model and save it, when execute save the shell show this error: La propiedad [{0}] de la clase [{1}] no puede ser nulo But if i set the constraint nullable to true, the error show again. I think that i should not set this cosntraint. The model is linked to a mysql table with all properties except id allow null. I think I am not doing something wrong here. Any advice?? Domain: Modulo class Modulo { String nombre String icon String url //static constraint = { // url(nullable:true) //} } Controller: Example class ExampleController { def index = { def modulo = new Modulo( nombre:'xxx', icon:'xxx' ) if (modulo.save()){ println 'ok' }else{ modulo.errors.allErrors.each { println it.defaultMessage} } } } Thanks. José

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  • How to Cache image when src is some action which returns image?

    - by Bipul
    There are lots of questions about how to force the browser to cache or not to cache any image. But, I am facing slightly different situation. In several places of my web page, I am using following code for the images. <img title="<%= Html.Encode(Model.title)%>" src="<%= Url.Action(MVC.FrontEnd.Actions.RetrieveImage(Model.SystemId))%>"/> So, in the generated HTML it is like <img title="blahblah" src="http://xyz.com/FrontEnd/Actions/RetrieveImage?imageId=X"> Where X is some integer. I have seen that though the browser (IE or Mozilla) caches images by default, it is not caching images generated by above method. Is there any way I can tell browser to cache images of above type? Thanks in advance.

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  • Hierarchical Data in MySQL is fast to retrieve?

    - by ajsie
    i've got a list of all countries - states - cities (- subcities/villages etc) in a XML file and to retrieve for example a state's all cities it's really quick with XML (using xml parser). i wonder, if i put all this information in mysql, is retrieving a state's all cities as fast as with XML? cause XML is designed to store hierarchical data while relational databases like mysql are not. the list contains like 500 000 entities. so i wonder if its as fast as XML using either of: Adjacency list model Nested Set model And which one should i use? Cause (theoretically) there could be unlimited levels under a state. And which is fastest for this huge dataset? Thanks!

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  • How do I get the position of a result in the list after an order_by?

    - by Bob Bob
    I'm trying to find an efficient way to find the rank of an object in the database related to it's score. My naive solution looks like this: rank = 0 for q in Model.objects.all().order_by('score'): if q.name == 'searching_for_this' return rank rank += 1 It should be possible to get the database to do the filtering, using order_by: Model.objects.all().order_by('score').filter(name='searching_for_this') But there doesn't seem to be a way to retrieve the index for the order_by step after the filter. Is there a better way to do this? (Using python/django and/or raw SQL.) My next thought is to pre-compute ranks on insert but that seems messy.

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  • logging in scala

    - by IttayD
    In Java, the standard idiom for logging is to create a static variable for a logger object and use that in the various methods. In Scala, it looks like the idiom is to create a Logging trait with a logger member and mixin the trait in concrete classes. This means that each time an object is created it calls the logging framework to get a logger and also the object is bigger due to the additional reference. Is there an alternative that allows the ease of use of "with Logging" while still using a per-class logger instance? EDIT: My question is not about how one can write a logging framework in Scala, but rather how to use an existing one (log4j) without incurring an overhead of performance (getting a reference for each instance) or code complexity. Also, yes, I want to use log4j, simply because I'll use 3rd party libraries written in Java that are likely to use log4j.

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  • Reading Ontology with Jena, feeding it with RDF triples, and producing correct RDF string output.

    - by JonB
    Hi, I have an ontology, which I read in with Jena to help me scrape some RDFa triples from a website. I don't currently store these triples in a Jena model, but that is fairly straight forward to do, its on my to do next list. The area I am struggling with, though, is to get Jena to output correct RDF for the ontology I have. The ontology uses Owl and RDFS definitions, but when I pass some example triples into the model, they don't appear correctly. Almost as if it doesn't know anything about the ontology. The output is, however, still valid RDF, just it's not coming out in the form I was hoping for. Am I correct in thinking that Jena should be able to produce well written RDF (not just valid) about the triples I have collected, based on the ontology or does this out stretch what it is capable of? Many thanks for any input.

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  • readobject method throws ClassNotFoundException

    - by eruina
    Hi all, I'm trying to pick up Java and wanted to test around with Java's client/server to make the client send a simple object of a self defined class(Message) over to the server. The problem was that I kept getting a ClassNotFoundException on the server side. I think the rest of the codes seem to be alright because other objects such as String can go through without problems. I had two different netbeans projects in different locations for client and server each. Each of them have their own copy of Message class under their respective packages. Message class implements Serializable. On the client side, I attempt to send a Message object through. On the server side, upon calling the readObject method, it seems to be finding Message class from the client's package instead of it's own. printStackTrace showed: "java.lang.ClassNotFoundException: client.Message" on the server side I have not even tried to cast or store the object received yet. Is there something I left out?

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  • pros and cons of TryCatch versus TryParse

    - by Vijesh
    What are the pros and cons of using either of the following approaches to pulling out a double from an object? Beyond just personal preferences, issues I'm looking for feedback on include ease of debugging, performance, maintainability etc. public static double GetDouble(object input, double defaultVal) { try { return Convert.ToDouble(input); } catch { return defaultVal; } } public static double GetDouble(object input, double defaultVal) { double returnVal; if (double.TryParse(input.ToString(), out returnVal)) { return returnVal; } else { return defaultVal; } }

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  • setting value to the instance of primitive types

    - by Samreen
    I have a function which performs some operation i.e. fetches some data from database. The generic it takes is primitive type always i.e. int, char, bool, string etc. I can easily create its instance. But I can't set the value that I have fetched from database to this instance. public T PerformOperation<T>() { object instance = (T)Activator.CreateInstance(typeof(T)); object result=FetchData(); instance = (T)result; //It gives error on this statement } The function is called as: int result = PerformOperation<int>(); Is there some way of casting the object Type to any generic type which is always primitive?

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