Inject a dependency into a custom model binder and using InRequestScope using Ninject

Question

I\'m using NInject with NInject.Web.Mvc.

To start with, I\'ve created a simple test project in which I want an instance of IPostRepository to be shared

Answer 1

I eventually managed to solve it with a factory as suggested. However, I just could not figure out how to accomplish this with Ninject.Extensions.Factory which is what I would've preferred. Here is what I ended up with:

The factory interface:

public interface IPostRepositoryFactory
{
    IPostRepository CreatePostRepository();
}

The factory implementation:

public class PostRepositoryFactory : IPostRepositoryFactory
{
    private readonly string key = "PostRepository";

    public IPostRepository CreatePostRepository()
    {
        IPostRepository repository;

        if (HttpContext.Current.Items[key] == null)
        {
            repository = new PostRepository();
            HttpContext.Current.Items.Add(key, repository);
        }
        else
        {
            repository = HttpContext.Current.Items[key] as PostRepository;
        }

        return repository;
    }
}

The Ninject module for the factory:

public class PostRepositoryFactoryModule : NinjectModule
{
    public override void Load()
    {
        this.Bind().To();
    }
}

The custom model binder:

public class CustomModelBinder : DefaultModelBinder
{
    private IPostRepositoryFactory factory;

    public CustomModelBinder(IPostRepositoryFactory factory)
    {
        this.factory = factory;
    }

    public override object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
    {
        IPostRepository repository = factory.CreatePostRepository();

        repository.Add("Model binder");

        return base.BindModel(controllerContext, bindingContext);
    }
}

The controller:

public class HomeController : Controller
{
    private IPostRepository repository;

    public HomeController(IPostRepositoryFactory factory)
    {
        this.repository = factory.CreatePostRepository();
    }

    public ActionResult Index(string whatever)
    {
        repository.Add("Action method");

        return View(repository.GetList());
    }
}

Global.asax to wire up the custom model binder:

protected override void OnApplicationStarted()
{
    AreaRegistration.RegisterAllAreas();

    RegisterGlobalFilters(GlobalFilters.Filters);
    RegisterRoutes(RouteTable.Routes);

    ModelBinders.Binders.Add(typeof(string), kernel.Get());
}

Which in my view, gave me the desired output of:

Model binder
Action method