Autofac Constructor Injection by Attribute

Question

I have a class that currently takes an IIndex in order to select an indexed dependency. I'd like to change that to somehow using an attribute on the constructor argument, in order to directly specify which one to use.

I'm pretty sure Autofac doesn't support this natively, but I'm not afraid to write my own attribute for this. I've messed around with the source side of Autofac before (custom registration sources, etc.) but I've never seen a way of tailoring the injection side. Can anyone help?

P.S.: I've seen this question but it turned into a discussion on the benefits of attribute-based injection. OTOH, I already decided I don't want to have to manually register each one of my types that depends on this particular dependency one-by-one, so I'd prefer it.

Answer 1

You can achieve this by scanning your class metadata on resolving an interface. When you get info about its parameters you can resolve actual implementation of the interface. See my answer here.

Answer 2

I noticed http://code.google.com/p/autofac/wiki/WebFormsIntegration says we can create a Custom Dependency Injection Models by implementing IInjectionBehaviour, I think it worth a try.