How do I combine a Controlled Lifetime relationship type (i.e. Owned<T>) with a delegate factory? - autofac

Question

In my application, I have a service that requires a constructor parameter not resolved by Autofac, that I instantiate using a delegate factory:
public class Service
{
public Service(string parameter /*, ... other dependencies */)
{
}
public delegate Service Factory(string parameter);
}
This works great! I really love this feature.
I also like the Controlled Lifetime relationship, so I can let my component depend on a Func<Owned<ISomething>> like this:
public class Component
{
private Func<Owned<ISomething>> _somethingFactory;
/* constructor omitted for brevity */
public void DoSomethingUseful()
{
using (var ownedSomething = _somethingFactory())
{
/* Lots of useful code here */
}
}
}
My problem is that now I want to combine the two. I can't have an instance of Func<Owned<Service>> injected, because it needs that parameter, so my current solution is to abstract the factory away into another service, say IServiceFactory:
public interface IServiceFactory
{
Service Create(string parameter);
}
...implemented as such:
public class ServiceFactory : IServiceFactory
{
private Service.Factory _internalFactory;
public ServiceFactory(Service.Factory internalFactory)
{
_internalFactory = internalFactory;
}
public Service Create(string parameter)
{
return _internalFactory(parameter);
}
}
My component then becomes this:
public class Component
{
Func<Owned<IServiceFactory>> _serviceFactoryFactory;
/* ... */
}
The need for such a field name leaves a bad taste in my mouth to the point that I suspect there must be a cleaner way to handle this case.
Is there another way?

Answer 1

You could change your injected factory to include the string parameter:
private Func<string, Owned<ISomething>> _somethingFactory;
Then you can pass the string to the factory when you want to create a new instance:
public void DoSomethingUseful()
{
using (var ownedSomething = _somethingFactory("my parameter"))
{
/* Lots of useful code here */
}
}
I've created a .NET Fiddle with a small working sample.