ASP.NET MVC3 Model Validation using Interface Attributes

After reading Brad Wilson’s post on that, I thought to myself:

Brad is 100% correct regarding the way the CLR treat interface attributes, but this does not mean the users should not be able to use validation attributes on model interfaces

So I sat down to extend the model validation to do just that: (see https://gist.github.com/1163635 if it is broken here)

Now I know it is hacky – it should not go on a FilterAttributes() method. If I had access to the sources I’d have added a virtual “GetValidationAttribute” method on DataAnnotationsModelMetadataProvider… (hint hint hint)