A small Library to configure Ninject (A Dependency Injection Library) with a WebAPI Application.

Ninject.Http.cs

using Ninject.Modules;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Web;
using System.Web.Http;
using System.Web.Http.Dependencies;

//  A small Library to configure Ninject (A Dependency Injection Library) with a WebAPI Application. 
//  To configure, take the following steps.
// 
//  1. Install Packages Ninject and Ninject.Web.Common 
//  2. Remove NinjectWebCommon.cs in your App_Start Directory
//  3. Add this file to your project  (preferrably in the App_Start Directory)  
//  4. Add Your Bindings to the Load method of MainModule. 
//     You can add as many additional modules to keep things organized
//     simply add them to the Modules property of the NinjectModules class
//  5. Add the following Line to your Global.asax
//          NinjectHttpContainer.RegisterModules(NinjectHttpModules.Modules);  
//  5b.To Automatically Register all NinjectModules in the Current Project, You should instead add
//          NinjectContainer.RegisterAssembly()
//  You are done. 

namespace Ninject.Http
{
    /// <summary>
    /// Resolves Dependencies Using Ninject
    /// </summary>
    public class NinjectHttpResolver : IDependencyResolver, IDependencyScope
    {
        public IKernel Kernel { get; private set; }
        public NinjectHttpResolver(params NinjectModule[] modules)
        {
            Kernel = new StandardKernel(modules);
        }

        public NinjectHttpResolver(Assembly assembly)
        {
            Kernel = new StandardKernel();
            Kernel.Load(assembly);
        }

        public object GetService(Type serviceType)
        {
            return Kernel.TryGet(serviceType);
        }

        public IEnumerable<object> GetServices(Type serviceType)
        {
            return Kernel.GetAll(serviceType);
        }

        public void Dispose()
        {
            //Do Nothing
        }

        public IDependencyScope BeginScope()
        {
            return this;
        }
    }


    // List and Describe Necessary HttpModules
    // This class is optional if you already Have NinjectMvc
    public class NinjectHttpModules
    {
        //Return Lists of Modules in the Application
        public static NinjectModule[] Modules
        {
            get
            {
                return new[] { new MainModule() };
            }
        }

        //Main Module For Application
        public class MainModule : NinjectModule
        {
            public override void Load()
            {
                //TODO: Bind to Concrete Types Here
            }
        }
    }


    /// <summary>
    /// Its job is to Register Ninject Modules and Resolve Dependencies
    /// </summary>
    public class NinjectHttpContainer
    {
        private static NinjectHttpResolver _resolver;

        //Register Ninject Modules
        public static void RegisterModules(NinjectModule[] modules)
        {
            _resolver = new NinjectHttpResolver(modules);
            GlobalConfiguration.Configuration.DependencyResolver = _resolver;
        }

        public static void RegisterAssembly()
        {
            _resolver = new NinjectHttpResolver(Assembly.GetExecutingAssembly());
            //This is where the actual hookup to the Web API Pipeline is done.
            GlobalConfiguration.Configuration.DependencyResolver = _resolver;
        }

        //Manually Resolve Dependencies
        public static T Resolve<T>()
        {
            return _resolver.Kernel.Get<T>();
        }
    }
}

This works great. Thanks. You just need to change the Global.asax.cs line needed for this WebApi implementation to NinjectHttpContainer.RegisterModules(NinjectHttpModules.Modules). I think you copied and pasted from the MVC example.

I have updated it. Thanks for pointing it out

Thanks odytrice..

This was nice and helpful :)
I have got this working with the MVC one.. works great

Cheers
Has

Great stuff odytrice, thanks for posting this

You can actually put both the MVC and API containers and resolvers together.

You just need to make NinjectHttpResolver also implement System.Web.Mvc.IDependencyResolver and then call System.Web.Mvc.DependencyResolver.SetResolver(_resolver) in both the RegisterModules and RegisterAssembly methods (use full namespace references, not using statements as it will cause ambiguity with the System.Web.Http namespace).

This will limit it to a single Kernel without having to extract Kernel creation to a static Singleton class.

@tkempton That's really cool. especially if you are doing both in the same project which btw happens a lot. The only thing you might need to deal with are the namespace collisions.

Thanks for this!

I already had most of these pieces in place but the configuration was not working with the setup I currently have.

In my app Web Api 2 is running on OWIN in its own IAppBuilder.Map("/api", ...); whereas the rest of the app is a large forms application/CMS that needs to communicate with the Web Api app.

I had been using WebActivators and GlobalConfiguration which was causing issues when OWIN authentication conflicted with the forms app authentication.