Autofac - global callback when object resolved

Question

How can I register global callback on Autofac container which is triggered whenever any object is resolved?

I want to use reflection and check if an object has a method called Initialize() and call it if it does. I want it to be duck typed i.e. no interfaces are required.

Thanks!

Answer 1

In Autofac you can use the IComponentRegistration interface to subscribe on various lifetime events:

• OnActivating
• OnActivated
• OnRelease

You can get the IComponentRegistration instance by creating a Module and override the AttachToComponentRegistration method:

public class EventModule : Module
{
    protected override void AttachToComponentRegistration(
        IComponentRegistry componentRegistry, 
        IComponentRegistration registration)
    {
        registration.Activated += OnActivated;
    }

    private void OnActivated(object sender, ActivatedEventArgs<object> e)
    {
        e.Instance.GetType().GetMethod("Initialize").Invoke(e.Instance, null);
    }
}

Now you only need to register your module in your container builder:

var builder = new ContainerBuilder();
builder.RegisterModule<EventModule>();

and the OnActivated method will be called after every component activation no mater in which module you have registered the component.