What is the best way to configure structuremap to instantiate a different class depending on the lifecycle..
e.g. for IUser, when it is HTTP context, I want to instantiate a User class, if there is no Http context I want structuremap to instantiate a ServiceUser class?
Related
I'm fairly new to Castle Windsor and in particular using Interceptors and am wondering if it is possible to register an Interceptor across all implementations of a particular interface without specifying each implementation in turn. For example, I have an interface called IComponent which will be implemented by a number of classes. I have a ComponentInterceptor class written to act on these classes when they have executed a particular method. I would like to do something like:
_container.Register(
Component.For<IComponent>()
.Interceptors("ComponentInterceptor")
.LifestyleSingleton())
Rather than having to do:
_container.Register(
Component.For<IComponent>()
.ImplementedBy<ComponentA>()
.Interceptors("ComponentInterceptor")
.LifestyleSingleton()),
_container.Register(
Component.For<IComponent>()
.ImplementedBy<ComponentB>()
.Interceptors("ComponentInterceptor")
.LifestyleSingleton())
I found another approach, I wanted to register this interceptor for all components being registered and do this hopefully minimal fuss. To do this I follow this article and created a new class like this:
public class MyContributeComponentConstruct : IContributeComponentModelConstruction
{
public void ProcessModel(IKernel kernel, ComponentModel model)
{
if (model.Services.Any(s => s == typeof(IComponent)))
{
model.Interceptors.Add(InterceptorReference.ForType<ComponentInterceptor>());
}
}
}
and then add this contribute with the Castle Windsor container
container.Kernel.ComponentModelBuilder.AddContributor(new MyContributeComponentConstruct ());
You can register components in the container using conventions via the Classes class. The following registers all classes in the current assembly that implement IComponent under the service IComponent and with your ComponentInterceptor interceptor:
container.Register(
Classes.FromThisAssembly()
.BasedOn<IComponent>()
.WithService.FromInterface()
.Configure(c => c.Interceptors<ComponentInterceptor>())
);
The Windsor documentation provides a bunch of other examples and explains in detail what different classes are for.
I have a REST service class in which uriInfo object is automatically injected through #UriInfo annotation. Now, while writing JUnit for this class, I want to get a mock object created for this UriInfo object without introducing any new setter methods into the tested class just for the sake of setting the mocked UriInfo into it. Kindly let me know if you have any suggestions. We are using EasyMock and PowerMock.
You can use Powermock's Whitebox to modify the internal state of an object. One of the simplest invocations is:
Whitebox.setInternalState(tested, myMock);
The AS3 Proxy class extends Object and exposes methods that you can override to handle the addition/removal and getting/setting of properties on the object in a universal fashion.
It appears that existing objects such as MovieClip, Sprite, etc. do not inherit from the Proxy class, so it would seem to preclude the possibility of adding such functionality to existing display object classes.
I've created a layout framework with a base display object class called GUIControl that inherits from MovieClip, and I was hoping to add data-binding functionality to it by overriding the Proxy class's setProperty method, so I could handle property assignments with a single handler to make all properties function as binding sources by default.
Is there some way to utilize the Proxy class's functionality on existing classes, or am I stuck building classes from scratch based on Proxy?
You may create a wrapper class for MovieClip and set property on the wrapper. You should override other functions in Proxy and call the relative functions on MovieClip.
Here is an example
import flash.display.MovieClip;
import flash.utils.Proxy;
import flash.utils.flash_proxy;
public class MovieClipWrapper extends Proxy
{
public function MovieClipWrapper(target:MovieClip)
{
super();
_target = target;
}
private var _target:MovieClip;
override flash_proxy function setProperty(name:*, value:*):void
{
//set data on target movieClip, or call the notify functions
}
}
No, it cannot be used on existing classes. The worst part is that rules out using Proxy on any display list classes. There is no way to alter a property on a display list class and have the Proxy class intercept and handle the setting or getting of such a property value. Proxy is useful only as a base class for new classes (ideally dynamic classes), where you want to intercept and run logic when properties are set/retreived/removed.
Futhermore, Proxy is useless for trying to wrap something like the Dictionary class, since Proxy's interface methods rely on QName and String-type keys exclusively, which makes it impossible to enumerate over, get, or set Dictionary values that use object instances as keys... something Dictionary supports unlike associative arrays or normal Objects.
I'm using NServiceBus (3.2.2), RavenDB (1.2.2017-Unstable) and Windsor (3.0.0.4001) in an MVC 4 project.
I have a IHandleMessages class that handles 3 different messages, and that needs an IDocumentSession, and therefore defines a property such as:
public IDocumentSession DocumentSession { get; set; }
I've copied the RavenDbUnitOfWork implementation from NServiceBus' website
I've registered IDocumentStore, IDocumentSession and IManageUnitsOfWork in my Windsor container as follow:
container.Register(
Component
.For<IManageUnitsOfWork>()
.ImplementedBy<RavenUnitOfWork>()
.LifestyleTransient()
);
container.Register(
Component
.For<IDocumentStore>()
.UsingFactoryMethod(k => DocumentStoreHolder.DocumentStore)
.LifestyleSingleton(),
Component
.For<IDocumentSession>()
.UsingFactoryMethod(k => k.Resolve<IDocumentStore>().OpenSession())
.LifestyleTransient()
);
NServiceBus is configured to use my container:
Configure.With()
.CastleWindsorBuilder(container);
I'm encountering the problem that the UnitOfWork and the message handler receive different instances of the DocumentSession. This means that objects stored in the session in the message handler are not saved, since SaveChanges() is called on a different DocumentSession.
Removing the Transient lifestyle causes different kind of problems, that result in concurrency/conflicts when updating objects from RavenDb, since (probably) the message handler keeps getting the same instance of the DocumentSession, which holds a cached version of the updated object.
Update:
As suggested, I've tried changing the registration of the IDocumentSession in Windsor, to the Scope lifestyle, like this:
Component
.For<IDocumentSession>()
.UsingFactoryMethod(k => k.Resolve<IDocumentStore>().OpenSession())
.LifestyleScope()
This causes exceptions when the container tries to resolve the MVC Controller, saying that the scope was not found, and asking if I forgot to call BeginScope().
You need to have a scope of Per Message, not transient or singleton.
I am assuming that your mvc controller has a direct dependency on the IDocumentStore. You need to call container.BeginScope() before each request from the web. You can either do this as an action filter attribute http://msdn.microsoft.com/en-us/library/system.web.mvc.actionfilterattribute.aspx or as an AOP aspect on the controller itself http://cangencer.wordpress.com/2011/06/02/asp-net-mvc-3-aspect-oriented-programming-with-castle-interceptors/.
The issue is you need different lifestyles when using nservicebus in an asp.net mvc website when sharing the IDocumentSession in the same container.
For ASP.NET MVC you need a PerWebRequest lifestyle and for NServiceBus you need the Scoped lifestyle.
To do that i've used the hybrid lifestyle code in the castle contrib project:
https://github.com/castleprojectcontrib/Castle.Windsor.Lifestyles/tree/master/Castle.Windsor.Lifestyles
When calling from an ASP.NET context, it uses the WebRequestScopeAccessor. For NServicebus you need the LifetimeScopeAccessor. This is not in the contrib project, but is easy to add:
public class HybridPerWebRequestLifetimeScopeScopeAccessor : HybridPerWebRequestScopeAccessor
{
public HybridPerWebRequestLifetimeScopeScopeAccessor()
: base(new LifetimeScopeAccessor())
{
}
}
And in your registration code you need something like:
container.Register(Component.For<IDocumentSession>().LifestyleScoped<HybridPerWebRequestLifetimeScopeScopeAccessor>().UsingFactoryMethod(() => RavenDbManager.DocumentStore.OpenSession()));
And here's an implementation for Rhino Service Bus i used before switching to nservicebus:
https://gist.github.com/4655544
A reference to the prototype object of a class or function object. The
prototype property is automatically created and attached to any class
or function object that you create. This property is static in that it
is specific to the class or function that you create. For example, if
you create a class, the value of the prototype property is shared by
all instances of the class and is accessible only as a class property.
Instances of your class cannot directly access the prototype property.
A class’s prototype object is a special instance of that class that
provides a mechanism for sharing state across all instances of a
class. At run time, when a property is not found on a class instance,
the delegate, which is the class prototype object, is checked for that
property. If the prototype object does not contain the property, the
process continues with the prototype object’s delegate checking in
consecutively higher levels in the hierarchy until Flash Player or the
Adobe Integrated Runtime finds the property.
Note: In ActionScript 3.0, prototype inheritance is not the primary
mechanism for inheritance. Class inheritance, which drives the
inheritance of fixed properties in class definitions, is the primary
inheritance mechanism in ActionScript 3.0.
So, from this I get the impression that prototypes are just static variables.. am I right?
Not exactly, a function implemented as a prototype is still executed as instance method. In a static function you don't have access to this.
Also it doesn't mean setting a prototype value to something is setting the value for every instance. It's only the fallback value, if an object of that class isn't setting it explicitly.
var o1:Object= {};
var o2:Object= {};
Object.prototype.foo = "foo";
o1.foo = "bar"
trace(o1.foo) // bar
trace(o2.foo) // foo