Automatic component registrations in Autofac

I just had to adapt my favorite IoC container to do some of the things MEF does out of the box, namely registering all classes that have a certain attribute (in MEF’s case, [Export]).

This is very easy with Autofac. I first created the attribute that would mark my “components” for registration (aka “exports”):

/// <summary>
/// Marks the decorated class as a component that will be available from 
/// the service locator / component container.
/// </summary>
[AttributeUsage(AttributeTargets.Class, AllowMultiple = false)]
public class ComponentAttribute : Attribute
{
    /// <summary>
    /// Initializes a new instance of the <see cref="ComponentAttribute"/> class, 
    /// marking the decorated class as a component that will be available from 
    /// the service locator / component container, registered with all 
    /// implemented interfaces as well as the concrete type.
    /// </summary>
    public ComponentAttribute()
    {
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="ComponentAttribute"/> class, 
    /// marking the decorated class as a component that will be available from 
    /// the service locator / component container using the specified 
    /// <paramref name="registerAs"/> type.
    /// </summary>
    /// <param name="registerAs">The type to use to register the decorated component.</param>
    public ComponentAttribute(Type registerAs)
    {
        this.RegisterAs = registerAs;
    }

    /// <summary>
    /// Type to use for the component registration.
    /// </summary>
    public Type RegisterAs { get; private set; }
}...

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