Is there a way to explicitly register open generic decorators with castle windsor

Question

I use castle windsor a lot in a project i'm working on and use decorators a little so I might have something like this in my installer

Component.For<IMyViewModelService>().ImplementedBy<MyViewModelServiceCacheDecorator>().LifestyleTransient()
Component.For<IMyViewModelService>().ImplementedBy<MyViewModelService>().LifestyleTransient()

So doing this is easy enough and works well. I started reading around the simple injector framework and I really like they way you can specifically set the decorators on open generics when using the command pattern.

https://simpleinjector.readthedocs.org/en/latest/advanced.html#decorators

Does castle windsor have any functionality that allows you to do the same thing in this declarative manner? I'm using castle windsor 3.3 and always stay with the latest.

I see this question which is kind of similar but doesn't have a full outcome registering open generic decorators for typed implementations in castle windsor

Answer 1

Perhaps I'm not understanding what you're trying to do, but Castle supports open generic decorators just fine. Given these objects:

public interface IService<T>
{
    void Info();
}

public class Service<T> : IService<T>
{
    public void Info()
    {
        Console.WriteLine(GetType());
    }
}

public class ServiceDecorator<T> : IService<T>
{
    readonly IService<T> service;

    public ServiceDecorator(IService<T> service)
    {
        this.service = service;
    }

    public void Info()
    {
        Console.WriteLine(GetType());
        service.Info();
    }
}

And this registration and resolution:

container.Register(Component.For(typeof(IService<>)).ImplementedBy(typeof(ServiceDecorator<>)));
container.Register(Component.For(typeof(IService<>)).ImplementedBy(typeof(Service<>)));

Then resolving the service and calling Info:

IService<int> service = container.Resolve<IService<int>>();
service.Info();

Will print:

Sample.ServiceDecorator`1[System.Int32]
Sample.Service`1[System.Int32]

If this is not what you're trying to do, please update your question with a more precise example.