is it possible to use Validation Application Block with WCF REST service?

Question

I'm using WCF REST service with API key template and trying to enforce validation using Validation Application Block attribute validation. here is my service:

[ServiceContract]
[AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]
[ServiceBehavior(InstanceContextMode = InstanceContextMode.PerCall)]
[ValidationBehavior]
public class Service1
{
    [FaultContract(typeof(ValidationFault))]
    [WebGet(UriTemplate = "ValidateStuff?text={text}")]
    public void ValidateStuff(
        [NotNullValidator]
        string text)
    {
    }

and the global.asax from the template:

public class Global : HttpApplication
    {
        void Application_Start(object sender, EventArgs e)
        {
            RegisterRoutes();
        }

        private void RegisterRoutes()
        {
            // Edit the base address of Service1 by replacing the "Service1" string below
            RouteTable.Routes.Add(new ServiceRoute("Service1", new WebServiceHostFactory(), typeof(Service1)));
        }
    }

then I have a client sending a GET request:

HttpWebRequest invokeRequest = WebRequest.Create(String.Concat(baseUrl, "/", uri, queryString)) as HttpWebRequest;
invokeRequest.Method = Enum.GetName(typeof(Method), method); 
WebResponse response = invokeRequest.GetResponse())

now the problem is that I get HTTP/1.1 500 Internal Server Error everytime.

if I remove the [ValidationBehavior] [FaultContract(typeof(ValidationFault))] and [NotNullValidator] attributes then everything works just fine. I checked service trace and didnt see anything that can help me.

Answer 1

The answer is that it is indeed possible! I found out what's the problem. I was missing references to:

Microsoft.Practices.ServiceLocation.dll
Microsoft.Practices.Unity.dll
Microsoft.Practices.Unity.Interception.dll

The strage thing is that I didn't see any indication for that in the trace log nor debug mode. The only way I found out was when I was trying to do the validation manually in the operation implementation itself, like so:

//at this point I got the exception saying that I'm missing the above references.
var validationResult = Validation.Validate<T>(TInstance); 

Hope it helps somebody