How to inject dependencies into a custom UserNamePasswordValidator in WCF?

Question

I'm using a UserNamePasswordValidator in WCF along with Unity for my dependency injection, but since WCF creates the instance of the UserNamePasswordValidator, I cannot inject my container into the class. So how would one go about this?

The simplest solution I can think of is to create a static proxy/wrapper class around a static instance of a UnityContainer, which exposes all the same methods... This way, any class can access the container, and I don't need to inject it everywhere.

So I could just do UnityContainerWrapper.Resolve() anywhere in code. So basically this solution solves 2 problems for me, I can use it in classes that I'm not creating an instance of, and I can use it anywhere without having to inject the container into a bunch of classes.

The only downside I can think of is that I'm now potentially exposing my container to a bunch of classes that wouldn't of had access to the container before. Not really sure if this is even a problem though?

Answer 1

Yes, this downsite is realy bad, and you should avoid it. In your case you can do something like this

public class CustomUserNameValidator : UserNamePasswordValidator
    {
        public static CustomUserNameValidator Current {
            get; private set;
        }

        public CustomUserNameValidator() {
            Current = this;
        }

        public override void Validate(string userName, string password)
        {
            throw new FaultException("No pasaran");

        }

        [Dependency]
        public ISomeService Service {
            get; set;
        }
    }

It will be created only once for service when service host is created, so you should write following code

 using (ServiceHost serviceHost = new ServiceHost(typeof(CalculatorService))) //here it will be created
            {
                container.BuildUp(CustomUserNameValidator.Current); //here you can inject all you need
             }

This is just inverted idea with static wrapper of the unity container :)