Authorization and Windsor

Question

I'm trying to implement my custom authorize attribute like:

 public class MyCustomAuth : AuthorizeAttribute
{
    private readonly IUserService _userService;

    public MyCustomAuth(IUserService userService)
    {
        _userService= userService;
    }
... continued
 }

I am using Castle Windsor for automatically resolve the dependency.

When I try to use it as an attribute of an action method obviously I am asked to pass the parameter or I need to have a parameter-less constructor that should resolve in some way it's dependency.

I tried to inject the dependency with a property but Windsor is not injecting it.

The only option I see now would be to instantiate manually the concrete object dependency loosing the benefit of Windsor.

How would you solve this problem?

Answer 1

You cannot use DI with attributes - they're metadata;

public class MyCustomAuth : AuthorizeAttribute
{
    public void OnAuthorization(...)
    {
         IUserService userService = ServiceLocator.Current.GetInstance<IUserService>();
    }
}

Learn about Windsor/ServiceLocator here.

See similar question here.

Answer 2

You can use a custom ControllerActionInvoker and inject property dependencies (you can't do constructor injection because the framework handles instantiation of attributes). You can see a blog post I just did on this technique.