Ninject dependency injection with Decorator pattern

Question

Say, I have such classes hierarchy:

public interface IRepository { }  public class SomeSimpleRepository : IRepository {} 

Now I want to "decorate" SomeSimpleRepository with additional functions

public class MoreAdvancedRespository : IRepository  {      private readonly IRepository _originalRepository;      public MoreAdvancedRespository(IRepository original)      { } } 

After awhile another one..

public class TrickyRepository : IRepository {     private readonly IRepository _originalRepository;      public TrickyRepository (IRepository original)      { } } 

Now, I need to accomplish binding. In application I need the instance of TrickyRepository, to be initialized with MoreAdvancedRespository. So, I need to write something like:

Bind<IRepository>().To<TrickyRepository>.With ?? 

Here I'm confused, I need somehow to say, take MoreAdvancedRespository but initialize it with SomeSimpleRepository. This is a kind of chain of dependencies that have to be resolved against one interface.

Does any one have suggestion on this?

Answer 1

Use WhenInjectedInto:

Bind<IRepository>().To<MoreAdvancedRespository>                    .WhenInjectedInto<TrickyRepository>(); Bind<IRepository>().To<SomeSimpleRepository>                    .WhenInjectedInto<MoreAdvancedRespository>(); 

See this blog post for more info.