Using Ninject with Asp.NET Web API Beta ApiController

Question

I'm stuck. I was using the method outlined here for wcf web api p6 Ninject working with WCF Web API Preview 5, however things are quite a bit different with the mvc implementation in the beta. There is a good article here http://www.asp.net/web-api/overview/extensibility/using-the-web-api-dependency-resolver that talks about building your own custom dependency resolver, however i would like to use the same implementation i'm using for my mvc view controllers...e.g. Ninject. I've tried a few things based on the IoC Unity example in the article too, but nothing has panned out yet. Any help pointing me in the right direction would be much appreciated. I'm going to keep digging on my own as well. Thanks in advance!

Here's where I'm at. I was using WebActivator to bootstrap the code but I've since dropped it to the Application_Start() just to take one more thing out of the equation.

    protected void Application_Start()
    {
        var kernel = new StandardKernel(new MyNinjectModule());
        GlobalConfiguration.Configuration.ServiceResolver.SetResolver(new NinjectDependencyResolver(kernel));
    }

And am receiving the following error:
The type Ninject.Web.Mvc.NinjectDependencyResolver does not appear to implement Microsoft.Practices.ServiceLocation.IServiceLocator.
Parameter name: commonServiceLocator

Found the solution
Perhaps there is/will be a more elegant way but this is now working for me. I'm also adding my custom message handler here as well.

[assembly: WebActivator.PreApplicationStartMethod(typeof(MyApp.AppStart.ApiBootstrapper), "Start")]
namespace MyApp.AppStart
{
    public class ApiBootstrapper
    {
        public static void Start()
        {
            var kernel = new StandardKernel(new MyNinjectModule());
            var resolver = new NinjectDependencyResolver(kernel);
            GlobalConfiguration.Configuration.ServiceResolver.SetResolver(resolver.GetService, resolver.GetServices);
            GlobalConfiguration.Configuration.MessageHandlers.Add(new ApiAuthHandler());
        }
    }
}

Answer 1

I never used the WebAPI but since the semantic of the IDependencyResolver is exactly the same as the one from MVC3 you should be able to use the same implementation: https://github.com/ninject/ninject.web.mvc/blob/master/mvc3/src/Ninject.Web.Mvc/NinjectDependencyResolver.cs

Update: The Ninject.Web.WebAPi extension adds support for ApiControllers

Answer 2

I found the answer and updated my question above with the solution. The solution itself was more or less present in the Using the Web API Dependency Resolver article, i just had to keep tweaking for ninject. Both answers helped me quickly narrow this down so thanks to @Remo and @James.

Answer 3

May sound silly but have you made sure you have a reference to the CommonServiceLocator / CommonServiceLocator.NinjectAdapter nuget package or associated assemblies. Your NinjectDependencyResolver may not be able to resolve the reference to IServiceLocator.

Answer 4

The same code will work for both MVC and the WebApi, however because the WebApi was inspired by MVC and the MVC assemblies do not have to be referenced in order to use WebApi (or vise versa), there is a fair amount of duplication of code between the two frameworks. If you want to use MVC you're dependencies will come from System.Web.Mvc, if you want to use WebApi you'll use System.Web.Http. If you want to use both you'll have to differentiate in your code which to use when, using a more explicit namespace resolution.

In your case your problem is that MVC came first and the NinjectDependancyResolver class inherits from System.Web.Mvc.IDependencyResolver. You'll want to create an exact duplicate of the NinjectDependancyResolver class and instead inherit from System.Web.Http.IDependencyResolver instead. Use THIS class to setup your IoC and you'll be good to go.

Answer 5

I found a nice solution here.

It's pretty easy if you're already using the Ninject CommonServiceLocator / Bootstrapper:

private static IKernel CreateKernel() {
   var kernel = new StandardKernel();
   RegisterServices(kernel);

   GlobalConfiguration.Configuration.ServiceResolver
      .SetResolver(new NinjectServiceLocator(kernel));
   return kernel; 
}