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  • WPF HiercharchicalDataTemplate.DataType: How to react on interfaces?

    - by David Schmitt
    Problem I've got a collection of IThings and I'd like to create a HierarchicalDataTemplate for a TreeView. The straightforward DataType={x:Type local:IThing} of course doesn't work, probably because the WPF creators didn't want to handle the possible ambiguities. Since this should handle IThings from different sources at the same time, referencing the implementing class is out of question. Current solution For now I'm using a ViewModel which proxies IThing through a concrete implementation: public interface IThing { string SomeString { get; } ObservableCollection<IThing> SomeThings { get; } // many more stuff } public class IThingViewModel { public IThing Thing { get; } public IThingViewModel(IThing it) { this.Thing = it; } } <!-- is never applied --> <HierarchicalDataTemplate DataType="{x:Type local:IThing}"> <!-- is applied, but looks strange --> <HierarchicalDataTemplate DataType="{x:Type local:IThingViewModel}" ItemsSource="{Binding Thing.SomeThings}"> <TextBox Text="{Binding Thing.SomeString}"/> </HierarchicalDataTemplate> Question Is there a better (i.e. no proxy) way?

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  • Storing class constants (for use as bitmask) in a database?

    - by fireeyedboy
    Let's say I have a class called Medium which can represent different types of media. For instance: uploaded video embedded video uploaded image embedded image I represent these types with contants, like this: class MediumAbstract { const UPLOAD = 0x0001; const EMBED = 0x0010; const VIDEO = 0x0100; const IMAGE = 0x1000; const VIDEO_UPLOAD = 0x0101; // for convenience const VIDEO_EMBED = 0x0110; // for convenience const IMAGE_UPLOAD = 0x1001; // for convenience const IMAGE_EMBED = 0x1010; // for convenience const ALL = 0x1111; // for convenience } Thus, it is easy for me to do a combined search on them on an (abstract) repository, with something like: { public function findAllByType( $type ) { ... } } $media = $repo->findAllByType( MediumAbstract::VIDEO | MediumAbstract::IMAGE_UPLOAD ); // or $media = $repo->findAllByType( MediumAbstract::ALL ); // etc.. How do you feel about using these constant values in a concrete repository like a database? Is it ok? Or should I substitute them with meaningful data in the database. Table medium: | id | type | location | etc.. ------------------------------------------------- | 1 | use constants here? | /some/path | etc.. (Of course I'll only be using the meaningful constants: VIDEO_UPLOAD, VIDEO_EMBED, IMAGE_UPLOAD and IMAGE_EMBED)

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  • Add fields to Django ModelForm that aren't in the model

    - by Cyclic
    I have a model that looks like: class MySchedule(models.Model): start_datetime=models.DateTimeField() name=models.CharField('Name',max_length=75) With it comes its ModelForm: class MyScheduleForm(forms.ModelForm): startdate=forms.DateField() starthour=forms.ChoiceField(choices=((6,"6am"),(7,"7am"),(8,"8am"),(9,"9am"),(10,"10am"),(11,"11am"), (12,"noon"),(13,"1pm"),(14,"2pm"),(15,"3pm"),(16,"4pm"),(17,"5pm"), (18,"6pm" startminute=forms.ChoiceField(choices=((0,":00"),(15,":15"),(30,":30"),(45,":45")))),(19,"7pm"),(20,"8pm"),(21,"9pm"),(22,"10pm"),(23,"11pm"))) class Meta: model=MySchedule def clean(self): starttime=time(int(self.cleaned_data.get('starthour')),int(self.cleaned_data.get('startminute'))) return self.cleaned_data try: self.instance.start_datetime=datetime.combine(self.cleaned_data.get("startdate"),starttime) except TypeError: raise forms.ValidationError("There's a problem with your start or end date") Basically, I'm trying to break the DateTime field in the model into 3 more easily usable form fields -- a date picker, an hour dropdown, and a minute dropdown. Then, once I've gotten the three inputs, I reassemble them into a DateTime and save it to the model. A few questions: 1) Is this totally the wrong way to go about doing it? I don't want to create fields in the model for hours, minutes, etc, since that's all basically just intermediary data, so I'd like a way to break the DateTime field into sub-fields. 2) The difficulty I'm running into is when the startdate field is blank -- it seems like it never gets checked for non-blankness, and just ends up throwing up a TypeError later when the program expects a date and gets None. Where does Django check for blank inputs, and raise the error that eventually goes back to the form? Is this my responsibility? If so, how do I do it, since it doesn't evaluate clean_startdate() since startdate isn't in the model. 3) Is there some better way to do this with inheritance? Perhaps inherit the MyScheduleForm in BetterScheduleForm and add the fields there? How would I do this? (I've been playing around with it for over an hours and can't seem to get it) Thanks! [Edit:] Left off the return self.cleaned_data -- lost it in the copy/paste originally

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  • What is the best practice for using lock within inherited classes

    - by JDMX
    I want to know if one class is inheriting from another, is it better to have the classes share a lock object that is defined at the base class or to have a lock object defined at each inheritance level. A very simple example of a lock object on each level of the class public class Foo { private object thisLock = new object(); private int ivalue; public int Value { get { lock( thisLock ) { return ivalue; } } set { lock( thisLock ) { ivalue= value; } } } } public class Foo2: Foo { private object thisLock2 = new object(); public int DoubleValue { get { lock( thisLock2 ) { return base.Value * 2; } } set { lock( thisLock2 ) { base.Value = value / 2; } } } } public class Foo6: Foo2 { private object thisLock6 = new object(); public int TripleDoubleValue { get { lock( thisLock6 ) { return base.DoubleValue * 3; } } set { lock( thisLock6 ) { base.DoubleValue = value / 3; } } } } A very simple example of a shared lock object public class Foo { protected object thisLock = new object(); private int ivalue; public int Value { get { lock( thisLock ) { return ivalue; } } set { lock( thisLock ) { ivalue= value; } } } } public class Foo2: Foo { public int DoubleValue { get { lock( thisLock ) { return base.Value * 2; } } set { lock( thisLock ) { base.Value = value / 2; } } } } public class Foo6: Foo2 { public int TripleDoubleValue { get { lock( thisLock ) { return base.DoubleValue * 3; } } set { lock( thisLock ) { base.DoubleValue = value / 3; } } } } Which example is the preferred way to manage locking within an inherited class?

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  • What type of things can cause sgen msbuild task to fail intermittantly with Access Violation?

    - by Mark Allanson
    In our MSBuild file for our project we sgen an assembly containing classes used during xml serialization. The classes are generated via xsd.exe. We use the following SGen task configuration. <SGen ToolPath="$(SdkPath)" ShouldGenerateSerializer="true" UseProxyTypes="false" BuildAssemblyName="AssemblyName.dll" BuildAssemblyPath="Outputs" ContinueOnError="false" /> Intermittantly the following error is thrown when executing the msbuild script on our build server. Originally this error might have occurred once out of every 50 (CI) builds, recently the frequency has been increasing and it now occurs maybe 5-6 out of every 10 builds. The size of the assembly that is being Sgenned is about 410k (circa 35,000 lines of generated code), and when successfull the serialization assembly is about 1.7M in size. When it fails, the output is as follows: Unhandled Exception: System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt. E:\Path_ToBuild_Workspace\SolutionBuild.MSBuild(74,5): error MSB6006: "sgen.exe" exited with code -1073741819. We are using Hudson to manage our builds, so the msbuild and sgen processes are therefore spwaned by the Hudson.exe. There's not much out there on the interwebs regarding this type of error from SGen. Certainly nothing concrete.

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  • Why are all objects in this extension of usercontrol null at runtime?

    - by csciguy
    All, I have a simple class. public class Container : UserControl { public bool IsClickable { get; set; } } I have a class that extends this class. public class ScrollingContainer : Container { public void Draw() { } public void Update() { } } I have a custom class, that then extends ScrollingContainer. public partial class MaskContainer : ScrollingContainer { public MaskContainer() { InitializeComponent(); } } XAML <local:ScrollingContainer x:Class="Test.Types.MaskContainer" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:local="clr-namespace:GameObjects;assembly=GameObjects" mc:Ignorable="d" > </local:ScrollingContainer> In my mainpage.xaml, I have the following. <types:MaskContainer x:Name="maskContainer" Canvas.ZIndex="1" Width="Auto" Height="Auto"> <Canvas x:Name="maskCanvas"> <Button x:Name="button1" Content="test button"/> </Canvas> </types:MaskContainer> Why, at runtime, are both maskCanvas and button1 null? maskContainer is not null. The inheritance should be straightforward here. Container inherits usercontrol. Scrollable container inherits container. Mask Container inherits scrollable container. Why am I losing the fucntionality of the original base class at this level? Is it incorrect to add the element (button1) to the maskcontainer inside of the main.xaml? My end goal is to create a container that is reusable, but inherits all properties/methods that I've specified throughout the chain. Any help is appreciated.

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  • Prevent Ninject from calling Initialize multiple times when binding to several interfaces

    - by Ahe
    Hi We have a concrete singleton service which implements Ninject.IInitializable and 2 interfaces. Problem is that services Initialize-methdod is called 2 times, when only one is desired. We are using .NET 3.5 and Ninject 2.0.0.0. Is there a pattern in Ninject prevent this from happening. Neither of the interfaces implement Ninject.IInitializable. the service class is: public class ConcreteService : IService1, IService2, Ninject.IInitializable { public void Initialize() { // This is called twice! } } And module looks like this: public class ServiceModule : NinjectModule { public override void Load() { this.Singleton<Iservice1, Iservice2, ConcreteService>(); } } where Singleton is an extension method defined like this: public static void Singleton<K, T>(this NinjectModule module) where T : K { module.Bind<K>().To<T>().InSingletonScope(); } public static void Singleton<K, L, T>(this NinjectModule module) where T : K, L { Singleton<K, T>(module); module.Bind<L>().ToMethod(n => n.Kernel.Get<T>()); } Of course we could add bool initialized-member to ConcreteService and initialize only when it is false, but it seems quite a bit of a hack. And it would require repeating the same logic in every service that implements two or more interfaces. Thanks for all the answers! I learned something from all of them! (I am having a hard time to decide which one mark correct). We ended up creating IActivable interface and extending ninject kernel (it also removed nicely code level dependencies to ninject, allthough attributes still remain).

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  • executing stored procedure from Spring-Hibernate using Annotations

    - by HanuAthena
    I'm trying to execute a simple stored procedure with Spring/Hibernate using Annotations. Here are my code snippets: DAO class: public class UserDAO extends HibernateDaoSupport { public List selectUsers(final String eid){ return (List) getHibernateTemplate().execute(new HibernateCallback() { public Object doInHibernate(Session session) throws HibernateException, SQLException { Query q = session.getNamedQuery("SP_APPL_USER"); System.out.println(q); q.setString("eid", eid); return q.list(); } }); } } my entity class: @Entity @Table(name = "APPL_USER") @Inheritance(strategy = InheritanceType.SINGLE_TABLE) @DiscriminatorFormula(value = "SUBSCRIBER_IND") @DiscriminatorValue("N") @NamedQuery(name = "req.all", query = "select n from Requestor n") @org.hibernate.annotations.NamedNativeQuery(name = "SP_APPL_USER", query = "call SP_APPL_USER(?, :eid)", callable = true, readOnly = true, resultClass = Requestor.class) public class Requestor { @Id @Column(name = "EMPL_ID") public String getEmpid() { return empid; } public void setEmpid(String empid) { this.empid = empid; } @Column(name = "EMPL_FRST_NM") public String getFirstname() { return firstname; } ... } public class Test { public static void main(String[] args) { ApplicationContext ctx = new ClassPathXmlApplicationContext( "applicationContext.xml"); APFUser user = (APFUser)ctx.getBean("apfUser"); List selectUsers = user.getUserDAO().selectUsers("EMP456"); System.out.println(selectUsers); } } and the stored procedure: create or replace PROCEDURE SP_APPL_USER (p_cursor out sys_refcursor, eid in varchar2) as empId varchar2(8); fname varchar2(50); lname varchar2(50); begin empId := null; fname := null; lname := null; open p_cursor for select l.EMPL_ID, l.EMPL_FRST_NM, l.EMPL_LST_NM into empId, fname, lname from APPL_USER l where l.EMPL_ID = eid; end; If i enter invalid EID, its returning empty list which is OK. But when record is there, following exception is thrown: Exception in thread "main" org.springframework.jdbc.BadSqlGrammarException: Hibernate operation: could not execute query; bad SQL grammar [call SP_APPL_USER(?, ?)]; nested exception is java.sql.SQLException: Invalid column name Do I need to modify the entity(Requestor.class) ? How will the REFCURSOR be converted to the List? The stored procedure is expected to return more than one record.

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  • How do I setup NInject? (I'm getting can't resolve "Bind", in the line "Bind<IWeapon>().To<Sword>()

    - by Greg
    Hi, I'm getting confused in the doco how I should be setting up Ninject. I'm seeing different ways of doing it, some v2 versus v1 confusion probably included... Question - What is the best way in my WinForms application to set things up for NInject (i.e. what are the few lines of code required). I'm assuming this would go into the MainForm Load method. In other words what code do I have to have prior to getting to: Bind<IWeapon>().To<Sword>(); I have the following code, so effectively I just want to get clarification on the setup and bind code that would be required in my MainForm.Load() to end up with a concrete Samurai instance? internal interface IWeapon { void Hit(string target); } class Sword : IWeapon { public void Hit(string target) { Console.WriteLine("Chopped {0} clean in half", target); } } class Samurai { private IWeapon _weapon; [Inject] public Samurai(IWeapon weapon) { _weapon = weapon; } public void Attack(string target) { _weapon.Hit(target); } } thanks PS. I've tried the following code, however I can't resolve the "Bind". Where does this come from? what DLL or "using" statement would I be missing? private void MainForm_Load(object sender, EventArgs e) { Bind<IWeapon>().To<Sword>(); // <== *** CAN NOT RESOLVE Bind *** IKernel kernel = new StandardKernel(); var samurai = kernel.Get<Samurai>();

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  • Can the Diamond Problem be really solved?

    - by Mecki
    A typical problem in OO programming is the diamond problem. I have parent class A with two sub-classes B and C. A has an abstract method, B and C implement it. Now I have a sub-class D, that inherits of B and C. The diamond problem is now, what implementation shall D use, the one of B or the one of C? People claim Java knows no diamond problem. I can only have multiple inheritance with interfaces and since they have no implementation, I have no diamond problem. Is this really true? I don't think so. See below: [removed vehicle example] Is a diamond problem always the cause of bad class design and something neither programmer nor compiler needs to solve, because it shouldn't exist in the first place? Update: Maybe my example was poorly chosen. See this image Of course you can make Person virtual in C++ and thus you will only have one instance of person in memory, but the real problem persists IMHO. How would you implement getDepartment() for GradTeachingFellow? Consider, he might be student in one department and teach in another one. So you can either return one department or the other one; there is no perfect solution to the problem and the fact that no implementation might be inherited (e.g. Student and Teacher could both be interfaces) doesn't seem to solve the problem to me.

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  • What's it like being a financial programmer?

    - by Mike
    As a student who's done an internship at a Silicon Valley company(non-financial), I'm curious to know what it's like working for a financial company doing software development. I'd expect the hours to be longer, and the pay to be higher. Specifically, I have the following questions: What's the work/life balance really like? Are you expected to work 80 hours a week most weeks? For those who have worked in non-financial software engineering jobs, how does being a financial software engineer compare in terms of work/life balance? How much does it pay? I'm curious as to starting(i.e. just got a BS) pay, as well as "top out" pay. (I'd prefer concrete numbers - ballpark is fine). Also, bonuses would be useful information. What jobs do financial programmers typically have? Are most just general software engineers, or do people typically have very specialized(i.e. AI or systems) backgrounds? Also, do most programmers have PhDs? Are programmers typically required to be at work, or are financial companies generally flexible about letting programmers work from home? When at work, do programmers have to dress formally? What are the technology environments like? Are finance companies using state-of-the-art hardware and software, or are they generally more conservative in upgrading their equipment? What programming languages are typically used? If VBA(shudder) is used, is it a large part of a finance company's workflow? If you could turn back the clock, would you still be a financial programmer? I'm going to keep this post open a little bit longer to get some more responses.

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  • How to implement or emulate an "abstract" OCUnit test class?

    - by Quinn Taylor
    I have a number of Objective-C classes organized in an inheritance hierarchy. They all share a common parent which implements all the behaviors shared among the children. Each child class defines a few methods that make it work, and the parent class raises an exception for the methods designed to be implemented/overridden by its children. This effectively makes the parent a pseudo-abstract class (since it's useless on its own) even though Objective-C doesn't explicitly support abstract classes. The crux of this problem is that I'm unit testing this class hierarchy using OCUnit, and the tests are structured similarly: one test class that exercises the common behavior, with a subclass corresponding to each of the child classes under test. However, running the test cases on the (effectively abstract) parent class is problematic, since the unit tests will fail in spectacular fashion without the key methods. (The alternative of repeating the common tests across 5 test classes is not really an acceptable option.) The non-ideal solution I've been using is to check (in each test method) whether the instance is the parent test class, and bail out if it is. This leads to repeated code in every test method, a problem that becomes increasingly annoying if one's unit tests are highly granular. In addition, all such tests are still executed and reported as successes, skewing the number of meaningful tests that were actually run. What I'd prefer is a way to signal to OCUnit "Don't run any tests in this class, only run them in its child classes." To my knowledge, there isn't (yet) a way to do that, something similar to a +(BOOL)isAbstractTest method I can implement/override. Any ideas on a better way to solve this problem with minimal repetition? Does OCUnit have any ability to flag a test class in this way, or is it time to file a Radar? Edit: Here's a link to the test code in question. Notice the frequent repetition of if (...) return; to start a method, including use of the NonConcreteClass() macro for brevity.

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  • How to make designer generated .Net application settings portable

    - by Ville Koskinen
    Hello, I've been looking at modifying the source of the Doppler podcast aggregator with the goal of being able to run the program directly from my mp3 player. Doppler stores application settings using a Visual Studio designer generated Settings class, which by default serializes user settings to the user's home directory. I'd like to change this so that all settings would be stored in the same directory as the exe. It seems that this would be possible by creating a custom provider class which inherits the SettingsProvider class. Has anyone created such a provider and would like to share code? Update: I was able to get a custom settings provider nearly working by using this MSDN sample, i.e. with simple inheritance. I was initially confused as Windows Forms designer stopped working until I did this trick suggested at Codeproject: internal sealed partial class Settings { private MySettingsProvider settingsprovider = new MySettingsProvider(); public Settings() { foreach (SettingsProperty property in this.Properties) { property.Provider = settingsprovider; } ... The program still starts with window size 0;0 though. Anyone with any insight to this? Why the need to assing the provider in runtime---instead of using attributes as suggested by MSDN? Why the changes in how the default settings are passed to the application with the default settings provider vs. the custom one?

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  • How does it affect me as a developer/engineer/company that Android is open source

    - by danke
    I understand the concept of open source, but I just realized now that I understand it from only one view: when I open source my own code. I don't really understand what benefit I'm getting from receiving the same thing. As a regular developer (like the majority of us here), I did not spend the past 4 years of my life working on "developing" the android. So even though I'm a developer, I'm at the end of the developers chain when it comes to the Android (like most of us). I'm really more of an end user. So my interest in Android isn't really to dedicate all my time to it or work on improving its kernel or anything overly ambitious. So with that clear, as a developer considering developing for the Android, how does it really benefit me that it's open source? What's the added benefit that I'm missing? Can other developers share some concrete ways that its open source status actually affects us as developers. Basically I'm trying to understand how we, at this developer level, can make sense of the fact that it's open source, or is its open source status just hype for us at our end developer level. Thanks

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  • Considerations when architecting an extensible application using MEF

    - by Dan Bryant
    I've begun experimenting with dependency injection (in particular, MEF) for one of my projects, which has a number of different extensibility points. I'm starting to get a feel for what I can do with MEF, but I'd like to hear from others who have more experience with the technology. A few specific cases: My main use case at the moment is exposing various singleton-like services that my extensions make use of. My Framework assembly exposes service interfaces and my Engine assembly contains concrete implementations. This works well, but I may not want to allow all of my extensions to have access to all of my services. Is there a good way within MEF to limit which particular imports I allow a newly instantiated extension to resolve? This particular application has extension objects that I repeatedly instantiate. I can import multiple types of Controllers and Machines, which are instantiated in different combinations for a Project. I couldn't find a good way to do this with MEF, so I'm doing my own type discovery and instantiation. Is there a good way to do this within MEF or other DI frameworks? I welcome input on any other things to watch out for or surprising capabilities you've discovered that have changed the way you architect.

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  • Entity Framework - Foreign key constraints not added for inherited entity

    - by Tri Q
    Hello, It appears to me that a strange phenomenon is occurring with inherited entities (TPT) in EF4. I have three entities. 1. Asset 2. Property 3. Activity Property is a derived-type of Asset. Property has many activities (many-to-many) When modeling this in my EDMX, everything seems fine until I try to insert a new Property into the database. If the property does not contain any Activity, it works, but all hell breaks loose when I add some new activities to the new Property. As it turns out after 2 days of crawling the web and fiddling around, I noticed that in the EF store (SSDL) some of the constraints between entities were not picked up during the update process. Property_Activity table which links properties and activities show only one constraint FK_Property_Activity_Activity but FK_Property_Activity_Property was missing. I knew this is an Entity Framework anomoly because when I switched the relationship in the database to: Asset <-- Asset_Activity <-- Activity After an update, all foreign key constraints are picked up and the save is successful, with or without activities in the new property. Is this intended or a bug in EF? How do I get around this problem? Should I abandon inheritance altogether?

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  • How to get around the jslint error 'Don't make functions within a loop.'

    - by Ernelli
    I am working on making all of our JS code pass through jslint, sometimes with a lot of tweaking with the options to get legacy code pass for now on with the intention to fix it properly later. There is one thing that jslint complains about that I do not have a workround for. That is when using constructs like this, we get the error 'Don't make functions within a loop.' for (prop in newObject) { // Check if we're overwriting an existing function if (typeof newObject[prop] === "function" && typeof _super[prop] === "function" && fnTest.test(newObject[prop])) { prototype[prop] = (function (name, func) { return function () { var result, old_super; old_super = this._super; this._super = _super[name]; result = func.apply(this, arguments); this._super = old_super; return result; }; })(prop, newObject[prop]); } This loop is part of a JS implementation of classical inheritance where classes that extend existing classes retain the super property of the extended class when invoking a member of the extended class. Just to clarify, the implementation above is inspired by this blog post by John Resig. But we also have other instances of functions created within a loop. The only workaround so far is to exclude these JS files from jslint, but we would like to use jslint for code validation and syntax checking as part of our continuous integration and build workflow. Is there a better way to implement functionality like this or is there a way to tweak code like this through jslint?

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  • Force compile-time linking of all classes in a SWC

    - by aaaidan
    Using Flash CS4, I am making a game that has a dozen or so sounds and a couple of music tracks. To cut down on publish/compile time, I have moved the sounds and music into an (external) SWC, which is located in a "Library Path" for the project. This works, but with a caveat... Until before I externalised the assets, I had been dynamically instantiating the Sound objects of the embedded sound by getting their classes with getDefinitionByName. // something like... var soundSubClass:Class = Class(getDefinitionByName(soundClassName)); var mySound:Sound = new soundSubClass(); But now that they're located in an external SWC, I need to have "concrete" references to the classes in order to load them like this, otherwise they are not included in the published SWF, and there is a runtime error when getDefinitionByName tries to get a class that doesn't exist. So, my question: in Flash Professional CS4, is there any way to force a library's assets to be included, regardless of whether they are statically linked? FlashDevelop has a compiler option "SWC Include Libraries", which is exactly what I want, and is distinct from the "SWC Libraries" option. The description of the "SWC Include Libraries" option is "Links all classes inside a SWC file to the resulting application SWF file, regardless of whether or not they are used." (Also, it's important to me that all the assets are contained within the one compiled SWF. Linking at runtime isn't what I'm after.)

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  • How can I improve this design?

    - by klausbyskov
    Let's assume that our system can perform actions, and that an action requires some parameters to do its work. I have defined the following base class for all actions (simplified for your reading pleasure): public abstract class BaseBusinessAction<TActionParameters> : where TActionParameters : IActionParameters { protected BaseBusinessAction(TActionParameters actionParameters) { if (actionParameters == null) throw new ArgumentNullException("actionParameters"); this.Parameters = actionParameters; if (!ParametersAreValid()) throw new ArgumentException("Valid parameters must be supplied", "actionParameters"); } protected TActionParameters Parameters { get; private set; } protected abstract bool ParametersAreValid(); public void CommonMethod() { ... } } Only a concrete implementation of BaseBusinessAction knows how to validate that the parameters passed to it are valid, and therefore the ParametersAreValid is an abstract function. However, I want the base class constructor to enforce that the parameters passed are always valid, so I've added a call to ParametersAreValid to the constructor and I throw an exception when the function returns false. So far so good, right? Well, no. Code analysis is telling me to "not call overridable methods in constructors" which actually makes a lot of sense because when the base class's constructor is called the child class's constructor has not yet been called, and therefore the ParametersAreValid method may not have access to some critical member variable that the child class's constructor would set. So the question is this: How do I improve this design? Do I add a Func<bool, TActionParameters> parameter to the base class constructor? If I did: public class MyAction<MyParameters> { public MyAction(MyParameters actionParameters, bool something) : base(actionParameters, ValidateIt) { this.something = something; } private bool something; public static bool ValidateIt() { return something; } } This would work because ValidateIt is static, but I don't know... Is there a better way? Comments are very welcome.

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  • Import package problem in GWT

    - by Krt_Malta
    Hi! I'm developing an app using GWT Eclipse plug-in. (I'm also using GWT Designer but I don't think the problem is here). Previously when I wanted to communicate with a web service I created, I produced the "skeleton" classes from the WSDL url using Sun's wsimport tool. Then I would add the classes generated to a class folder in my Eclipse project. All worked well. However this doesn't seem to be working with GWT. I have these: VideoTutorialServiceService service = new VideoTutorialServiceService(); VideoTutorialService port = service.getVideoTutorialServicePort(); and I have VideoTutorialServiceService and VideoTutorialService underlined in red, the error saying videotutorialservice.VideoTutorialServiceService can not be found in source packages. Check the inheritance chain from your module; it may not be inheriting a required module or a module may not be adding its source path entries properly. .... I googled about it but I got confused. I'm a beginnier in GWT. How can I resolve this please? Thanks and regards, Krt_Malta

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  • using indexer to retrieve Linq to SQL object from datastore

    - by fearofawhackplanet
    class UserDatastore : IUserDatastore { ... public IUser this[Guid userId] { get { User user = (from u in _dataContext.Users where u.Id == userId select u).FirstOrDefault(); return user; } } ... } One of the developers in our team is arguing that an indexer in the above situation is not appropriate and that a GetUser(Guid id) method should be prefered. The arguments being that: 1) We aren't indexing into an in-memory collection, the indexer is basically performing a hidden SQL query 2) Using a Guid in an indexer is bad (FxCop flagged this also) 3) Returning null from an indexer isn't normal behaviour 4) An API user generally wouldn't expect any of this behaviour I agree to an extent with (most of) these points. But I'm also inclined to argue that one of the characteristics of Linq is to abstract the database access to make it appear that you're simply working with a bunch of collections, even though the lazy evaluation paradigm means those collections aren't evaluated until you run a query over them. It doesn't seem inconsistent to me to access the datastore in the same manner as if it was a concrete in-memory collection here. Also bearing in mind this is an inherited codebase which uses this pattern extensively and consistently, is it worth the refactoring? I accept that it might have been better to use a Get method from the start, but I'm not yet convinced that it's completely incorrect to be using an indexer. I'd be interested to hear all opinions, thanks.

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  • Drupal workflow action access integrated with taxonomy access control?

    - by groovehunter
    hi, I am building a DMS for our intranet and use a taxonomy hierarchy because we need access control that way. All company locations manage (upload,edit) their own documents but should be able to access all. This is inherited to the child terms and works fine. Additionally we want simple 3-step workflow (draft,published,archived). So i introduced roles for editor, publisher and docadmin and set permissions for the transitions. Also triggers to effectivly (un)publish documents. But (of course) a user of role publisher can do the transition for ALL documents. But we want publisher for each company location (top taxonomy level, see above). Could this be achieved? Do i have to set it up by myself (i guess "rules" is appropriate to do this) or is there another module helping. role inheritance was a guess, but that is only about roles (naturally). "module grants" i use and checked first option. That way my thoughts are going. I hope you get my idea resp. problem. drupal 6.16 current edit: I reread the docs and found ie. http://drupal.org/node/408018 Revisioning for categorized content. Will reread that.

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  • Where do you take mocking - immediate dependencies, or do you grow the boundaries...?

    - by Peter Mounce
    So, I'm reasonably new to both unit testing and mocking in C# and .NET; I'm using xUnit.net and Rhino Mocks respectively. I'm a convert, and I'm focussing on writing behaviour specifications, I guess, instead of being purely TDD. Bah, semantics; I want an automated safety net to work above, essentially. A thought struck me though. I get programming against interfaces, and the benefits as far as breaking apart dependencies goes there. Sold. However, in my behaviour verification suite (aka unit tests ;-) ), I'm asserting behaviour one interface at a time. As in, one implementation of an interface at a time, with all of its dependencies mocked out and expectations set up. The approach seems to be that if we verify that a class behaves as it should against its collaborating dependencies, and in turn relies on each of those collaborating dependencies to have signed that same quality contract, we're golden. Seems reasonable enough. Back to the thought, though. Is there any value in semi-integration tests, where a test-fixture is asserting against a unit of concrete implementations that are wired together, and we're testing its internal behaviour against mocked dependencies? I just re-read that and I think I could probably have worded it better. Obviously, there's going to be a certain amount of "well, if it adds value for you, keep doing it", I suppose - but has anyone else thought about doing that, and reaped benefits from it outweighing the costs?

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  • Fluent NHibernate automap a HasManyToMany using a generic type

    - by zulkamal
    I have a bunch of domain entities that can be keyword tagged (a Tag is also an entity.) I want to do a normal many-to-many (Tag - TagReview <- Review) table relationship but I don't want to have to create a new concrete relationship on both the Entity and Tag every single time I add a new entity. I was hoping to do a generic based Tag and do this: // Tag public class Tag<T> { public virtual int Id { get; private set; } public virtual string Name { get; set; } public virtual IList<T> Entities { get; set; } public Tag() { Entities = new List<T>(); } } // Review public class Review { public virtual string Id { get; private set; } public virtual string Title { get; set; } public virtual string Content { get; set; } public virtual IList<Tag<Review>> Tags { get; set; } public Review() { Tags = new List<Tag<Review>>(); } } Unfortunately I get an exception: ----> System.ArgumentException : Cannot create an instance of FluentNHibernate.Automapping.AutoMapping`1[Example.Entities.Tag`1[T]] because Type.ContainsGenericParameters is true. I anticipate there will be maybe 5-10 entities so mapping normally would be ok but is there a way to do something like this?

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  • chrome extension login security with iframe

    - by Weaver
    I should note, I'm not a chrome extension expert. However, I'm looking for some advice or high level solution to a security concern I have with my chrome extension. I've searched quite a bit but can't seem to find a concrete answer. The situation I have a chrome extension that needs to have the user login to our backend server. However, it was decided for design reasons that the default chrome popup balloon was undesirable. Thus I've used a modal dialog and jquery to make a styled popup that is injected with content scripts. Hence, the popup is injected into the DOM o the page you are visiting. The Problem Everything works, however now that I need to implement login functionality I've noticed a vulnerability: If the site we've injected our popup into knows the password fields ID they could run a script to continuously monitor the password and username field and store that data. Call me paranoid, but I see it as a risk. In fact,I wrote a mockup attack site that can correctly pull the user and password when entered into the given fields. My devised solution I took a look at some other chrome extensions, like Buffer, and noticed what they do is load their popup from their website and, instead, embed an iFrame which contains the popup in it. The popup would interact with the server inside the iframe. My understanding is iframes are subject to same-origin scripting policies as other websites, but I may be mistaken. As such, would doing the same thing be secure? TLDR To simplify, if I embedded an https login form from our server into a given DOM, via a chrome extension, are there security concerns to password sniffing? If this is not the best way to deal with chrome extension logins, do you have suggestions with what is? Perhaps there is a way to declare text fields that javascript can simply not interact with? Not too sure! Thank you so much for your time! I will happily clarify anything required.

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