Question

Is it possible to group components’ registrations by name using autofac?
For instance, the bellow code has two registrations for IDbContextProvider.
And I want WfcService to resolve only a named instance (“proxyless”) of IDbContextProvider.
I’d like to use something like DependsOnNamed(“proxyless”) method to explicitly set a dependency on a set of named instances that have the same name.

I want the whole system to use the default implementation of IDbContextProvider while successors of IWfcService should use their own named instances.

var builder = new ContainerBuilder();
builder.RegisterType<DbContextProvider>().As<IDbContextProvider>().As<IDbContextProvider>();
builder.RegisterType<ProxyLessDbContextProvider>().Named<IDbContextProvider>("proxyless");

builder.RegisterType<Repository>().As<IRepository>();//depends on IDbContextProvider 
builder.RegisterType<BusinessService>().As<IBusinessService>();//depends on IRepository

builder.RegisterType<WfcService>().As<IWfcService>().DependsOnNamed("proxyless");//depends on IBusinessService

IContainer container = builder.Build();

var wcf = container.Resolve<IWfcService>(); // should depend on "proxyless" IDbContextProvider

Answer 1

The most appropriate way to achieve described behavior is to use the separate scope with overridden registration. If you want to override a registration for WCF services you should

var _wcfScope = _container.BeginLifetimeScope(b=> 
{
    b.RegisterType<NewDbContextProvider>().As<DbContextProvider>();
    //put wcf services registration here because of the issue http://code.google.com/p/autofac/issues/detail?id=365
});
AutofacHostFactory.Container = _wcfScope;