How to register many for open generic in Autofac

Question

I'm new to Autofac (not to DI). Here is the situation:

I have these interfaces:

public interface IQuery<out TResult> : IQuery { }

public interface IQueryHandler<in TQuery, out TResult> where TQuery : IQuery<TResult> {
    TResult Handle(TQuery query);
}

and there is a lot of implementation of them in my solution:

class GetPersonQuery : IQuery<PersonModel> { }
class GetPersonQueryHandler : IQueryHandler<GetPersonQuery, PersonModel> { }

class GetArticleQuery : IQuery<ArticleModel> { }
class GetArticleQueryHandler : IQueryHandler<GetArticleQuery, ArticleModel> { }

class GetSomethingQuery : IQuery<IEnumerable<SomeModel>> { }
class GetSomethingQueryHandler : IQueryHandler<GetSomethingQuery, IEnumerable<SomeModel>> { }

and so on. I'm currently registering them like this:

builder.RegisterType<GetPersonQueryHandler>()
    .As<IQueryHandler<GetPersonQuery, PersonModel>>();

builder.RegisterType<GetArticleQueryHandler>()
    .As<IQueryHandler<GetArticleQuery, ArticleModel>>();

builder.RegisterType<GetSomethingQueryHandler>()
    .As<IQueryHandler<GetSomethingQuery, SomeModel>>();

// blah blah blah

As you can see, I have a many same registrations. In SimpleInjector (which I was using before), I could register all of them by a single line:

container.RegisterManyForOpenGeneric(
    typeof(IQueryHandler<,>),
    AppDomain.CurrentDomain.GetAssemblies());

Is it possible to do this stuff in Autofac?

Solution

You can do this with Autofac you just need to use the scanning feature and use the AsClosedTypesOf method:

AsClosedTypesOf(open) - register types that are assignable to a closed instance of the open generic type.

So your registration will look like this:

builder.RegisterAssemblyTypes(AppDomain.CurrentDomain.GetAssemblies())
       .AsClosedTypesOf(typeof (IQueryHandler<,>)).AsImplementedInterfaces();

Comments

[amiry jd]

Sorry ): I'm working with @Javad_Amiry's team (Kavand). That is because of the problem Javad_Amiry asked before (here and on codeplex). Unfortunately in this project we cannot use simple injector. But our main DI lib still is SimpleInjector. We used it in many projects and we'll continue using it. :)