How to "bind" attribute to action filter using Autofac?

Question

I have a custom authorization filter that has constructor injected dependencies.

public class CustomAuthorizationFilter : IAuthorizationFilter

And a generic attribute that just holds the data.

[AttributeUsage(AttributeTargets.Method | AttributeTargets.Class, AllowMultiple = false, Inherited = false)]
public class CustomAuthorizeAttribute : FilterAttribute

An approach I "borrowed" from here and I really enjoy the separation. I understand how the filter goes and "gets" the attribute, but I'm missing something with the wire-up.

How do I "bind" the attribute to the filter so that the filter is invoked when the attribute is present? Ninject appears to have a syntax for this. But I haven't figured out an equivalent in Autofac

If this is something I need to setup in the app outside of Autofac, that's fine too.

Thanks! Josh

Answer 1

You could use the same class to be the filter and the attribute. But you can also define another attribute and check if it was defined.

Then you must register your filter/attribute class: inside Global.asax, just like filters.Add(new HandleErrorAttribute());.

Inside the filterMethods (in your case, should be OnAuthorize), you can check if some other attribute IsDefined or if some property was defined.