How to force only anonymous access to controller action?

Question

I can use the [AllowAnonymous] attribute to permit a user to access a controller action, but is there an attribute to permit only anonymous users to an action? e.g. [AllowAnonymousOnly]

Answer 1

No. It doesn't exist.

However, you can create it by creating your own attribute inheriting from the AuthorizeAttribute.

Here's an example.

Yours would look like:

public class AllowAnonymousOnlyAttribute : AuthorizeAttribute
{    
    protected override bool AuthorizeCore(HttpContextBase httpContext)
    {
        // make sure the user is not authenticated. If it's not, return true. Otherwise, return false
    }
}