[seam-dev] @Unwrap implementation in weld-extensions

[Stuart Douglas]

I think that there is a real use case for something similar to the @Unwrap feature of seam 2.

I think that it would be possible to implement something like this:

@ConversationScoped
public class ManagedPersistenceContext
{

  EntityManager entityManager;

  @Unwrap
  @SomeQualifier
  public EntityManager produce(InjectionPoint injectionPoint)
  {
    entityManager.joinTransaction();
    return entityManager;
  }
}

public class MyClass
{
  @Inject @SomeQualifier EntityManager entityManager;
}

the way I envisage this working is that a proxy gets injected into MyClass, and this proxy calls ManagedPersistenceContext.produce to resolve the correct EntityManager to pass the call to every time a method is invoked on the proxy.

I am pretty sure I can implement this in weld-extensions using JDK proxies, does this sound like a good idea?

Stuart