Using Ninject as IOC container in ASP.NET MVC

Yesterday I tried to use Fluent NHibernate and Ninject in ASP.NET MVC project the first time to prepare for my personal project. After doing some reading and surfing around the Internet, I end up with a solution and it just works. And here is how I did.

First, I start with a Ninject module which is used to register dependencies

public class CustomNinjectModule : NinjectModule
{
    public override void Load()
    {
        Bind<ISessionFactory>().ToMethod(c => GetSessionFactory()).InSingletonScope();
        Bind<ISession>().ToMethod(c => c.Kernel.Get<ISessionFactory>().OpenSession()).InRequestScope();
    }

    public static ISessionFactory GetSessionFactory()
    {
        return Fluently.Configure()
            .Database(MsSqlConfiguration.MsSql2008.ConnectionString(c => c.FromConnectionStringWithKey("connectionString")))
            .Mappings(m => m.FluentMappings.AddFromAssemblyOf<ProductMap>())
            .BuildSessionFactory();
    }
}

In this custom module, I used FluentNHibernate to create instance of ISessionFactory. We only need one instance of ISessonFactory for the whole project so I keep in singleton scope. In opposite way, we need to create a ISession instance per web request so I set it in request scope.

Then I create a bootstrapper which is used to create the kernel with above module

public static class NinjectBootstrapper
{
    public static IKernel Kernel { get; private set; }

    public static void Initialize()
    {
        Kernel = new StandardKernel(new CustomNinjectModule());
    }
}

Because I uses Ninject as IOC, in a consistent way it's better if I also use it to create instances of controllers. So I create a custom controller factory

public class NinjectControllerFactory : DefaultControllerFactory
{
    private readonly IKernel _kernel;

    public NinjectControllerFactory(IKernel kernel)
    {
        _kernel = kernel;
    }

    protected override IController GetControllerInstance(RequestContext requestContext, Type controllerType)
    {
        try
        {
            return _kernel.Get(controllerType) as IController;
        }
        catch (Exception)
        {
            return base.GetControllerInstance(requestContext, controllerType);
        }
    }
}

The last thing I need to do is updating Application_Start in my MvcApplication to initialize dependecies and use the custom factory

protected void Application_Start()
{
    NinjectBootstrapper.Initialize();
    ControllerBuilder.Current.SetControllerFactory(new NinjectControllerFactory(NinjectBootstrapper.Kernel));

    AreaRegistration.RegisterAllAreas();

    RegisterRoutes(RouteTable.Routes);
}

Lesson learn:

• How to use Ninject to inject dependencies in ASP.NET MVC
• Understand about some Ninject scopes and how to create instance in the scopes (transient, singleton and request)
• How to retrieve dependencies from current context (IContext.Kernel.Get<ISessionFactory>())
• And object lifecycle management in Ninject (as you can see, I don't need to release instances of ISession after each request because Nijnect does it for me. For more details, you can find here)