c# - NinjectDependencyResolver fails binding ModelValidatorProvider

Question

I'm developing an ASP.NET Web Api 2.2 with C#, .NET Framework 4.5.1.

After updating my Web.Api to Ninject 3.2.0 I get this error:

Error activating ModelValidatorProvider using binding from ModelValidatorProvider to NinjectDefaultModelValidatorProvider
A cyclical dependency was detected between the constructors of two services.

Activation path:
  3) Injection of dependency ModelValidatorProvider into parameter defaultModelValidatorProviders of constructor of type DefaultModelValidatorProviders
  2) Injection of dependency DefaultModelValidatorProviders into parameter defaultModelValidatorProviders of constructor of type NinjectDefaultModelValidatorProvider
  1) Request for ModelValidatorProvider

Suggestions:
  1) Ensure that you have not declared a dependency for ModelValidatorProvider on any implementations of the service.
  2) Consider combining the services into a single one to remove the cycle.
  3) Use property injection instead of constructor injection, and implement IInitializable
     if you need initialization logic to be run after property values have been injected.

I get the exception in NinjectWebCommon:

public static class NinjectWebCommon 
{
    private static readonly Bootstrapper bootstrapper = new Bootstrapper();

    /// <summary>
    /// Starts the application
    /// </summary>
    public static void Start() 
    {
        DynamicModuleUtility.RegisterModule(typeof(OnePerRequestHttpModule));
        DynamicModuleUtility.RegisterModule(typeof(NinjectHttpModule));
        bootstrapper.Initialize(CreateKernel);
    }

    /// <summary>
    /// Stops the application.
    /// </summary>
    public static void Stop()
    {
        bootstrapper.ShutDown();
    }

    /// <summary>
    /// Creates the kernel that will manage your application.
    /// </summary>
    /// <returns>The created kernel.</returns>
    private static IKernel CreateKernel()
    {
        var kernel = new StandardKernel();
        try
        {
            kernel.Bind<Func<IKernel>>().ToMethod(ctx => () => new Bootstrapper().Kernel);
            kernel.Bind<IHttpModule>().To<HttpApplicationInitializationHttpModule>();

            RegisterServices(kernel);
            return kernel;
        }
        catch
        {
            kernel.Dispose();
            throw;
        }
    }

    /// <summary>
    /// Load your modules or register your services here!
    /// </summary>
    /// <param name="kernel">The kernel.</param>
    private static void RegisterServices(IKernel kernel)
    {
        var containerConfigurator = new NinjectConfigurator();
        containerConfigurator.Configure(kernel);
    }        
}

NinjectDependencyResolver class:

using Ninject;
using System;
using System.Collections.Generic;
using System.Web.Http.Dependencies;

namespace Matt.SocialNetwork.Web.Common
{
    public class NinjectDependencyResolver : IDependencyResolver
    {
        private readonly IKernel _container;

        public IKernel Container
        {
            get { return _container; }
        }

        public NinjectDependencyResolver(IKernel container)
        {
            _container = container;
        }

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

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

        public IDependencyScope BeginScope()
        {
            return this;
        }

        public void Dispose()
        {
            // noop
        }
    }
}

NinjectConfigurator class:

public class NinjectConfigurator
{
    public void Configure(IKernel container)
    {
        // Add all bindings/dependencies
        AddBindings(container);

        // Use the container and our NinjectDependencyResolver as
        // application's resolver
        var resolver = new NinjectDependencyResolver(container);
        GlobalConfiguration.Configuration.DependencyResolver = resolver;
    }

    // Omitted for brevity.
}

The strange thing is it compiles and works perfectly, but after update it doesn't work.

I have changed this public class NinjectDependencyResolver : IDependencyResolver, System.Web.Mvc.IDependencyResolver but it still doesn't work.

Any idea?

UPDATE

Debugging I see that the exception is thrown in NinjectDependencyResolver here:

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

It runs twice. First serviceType is IFilterProvider and second time serviceType is ModelValidatorProvider, and after that I get the exception.

These are the Ninject packages that I'm using:

<package id="Ninject" version="3.2.2.0" targetFramework="net451" />
<package id="Ninject.MVC5" version="3.2.1.0" targetFramework="net45" />
<package id="Ninject.Web.Common" version="3.2.3.0" targetFramework="net451" />
<package id="Ninject.Web.Common.WebHost" version="3.2.3.0" targetFramework="net451" />
<package id="Ninject.Web.WebApi" version="3.2.2.0" targetFramework="net451" />

The previous version for these assemblies were:

<package id="Ninject" version="3.2.2.0" targetFramework="net45" />
<package id="Ninject.MVC5" version="3.2.1.0" targetFramework="net45" />
<package id="Ninject.Web.Common" version="3.2.2.0" targetFramework="net451" />
<package id="Ninject.Web.Common.WebHost" version="3.2.0.0" targetFramework="net45" />
<package id="Ninject.Web.WebApi" version="3.2.0.0" targetFramework="net451" />

SECOND UPDATE

I have found that the problem is in this class:

public static class WebContainerManager
{
    public static IKernel GetContainer()
    {
        var resolver = GlobalConfiguration.Configuration.DependencyResolver as NinjectDependencyResolver;
        if (resolver != null)
        {
            return resolver.Container;
        }

        throw new InvalidOperationException("NinjectDependencyResolver not being used as the MVC dependency resolver");
    }

    public static T Get<T>()
    {
        return GetContainer().Get<T>();
    }
}

I set Dependency Resolver here:

public class NinjectConfigurator
{
    /// <summary>
    /// Entry method used by caller to configure the given 
    /// container with all of this application's 
    /// dependencies. Also configures the container as this
    /// application's dependency resolver.
    /// </summary>
    public void Configure(IKernel container)
    {
        // Add all bindings/dependencies
        AddBindings(container);

        // Use the container and our NinjectDependencyResolver as
        // application's resolver
        var resolver = new NinjectDependencyResolver(container);
        GlobalConfiguration.Configuration.DependencyResolver = resolver;
    }

And I use WebContainerManager in a class that inherits from ExceptionFilterAttribute:

public class UnhandledExceptionFilter : ExceptionFilterAttribute
{
    private readonly IExceptionLogHelper excepLogHelper;

    public UnhandledExceptionFilter()
        : this(WebContainerManager.Get<IExceptionLogHelper>()) {}

    public UnhandledExceptionFilter(IExceptionLogHelper exceptionLogHelper)
    {
        this.excepLogHelper = exceptionLogHelper;
    }

    public override void OnException(HttpActionExecutedContext actionExecutedContext)
    {
        this.excepLogHelper.LogException(actionExecutedContext);
    }
}

So, if I remove WebContainerManager I don't get that cycle.

Answer 1

I was having all sorts of grief with the WebApi2 and Ninject initialization after upgrading the Ninject packages (even uninstalling and deleting the old ones).

Specifically in your case I would remove these lines of code:

// Use the container and our NinjectDependencyResolver as
// application's resolver
var resolver = new NinjectDependencyResolver(container);
GlobalConfiguration.Configuration.DependencyResolver = resolver;

as they are probably the cause of the error (the NinjectWebCommon.cs and Ninject libraries deal with initializing the dependency resolver now).

---

For others out there who followed a similar upgrade path to me. What worked for me was the following:

• Remove the old DependencyResolver initialization code (for me this was causing the specific error you mention as in earlier versions of Ninject/WebApi2, putting these lines in the WebApiConfig.cs Register() method was how you initialized the DependencyResolver...this no longer is the case):

  var kernel = new StandardKernel();
  config.DependencyResolver = new NinjectDependencyResolver(kernel);
  

• Install the Ninject.Web.WebApi.WebHost package. This installed the NinjectWebCommon.cs file. For me, just having the Ninject.Web.WebApi and it's dependencies didn't create this file.

My installed and working Ninject Packages for reference:

<package id="Ninject" version="3.2.2.0" targetFramework="net452" />
<package id="Ninject.Web.Common" version="3.2.3.0" targetFramework="net452" />
<package id="Ninject.Web.Common.WebHost" version="3.2.0.0" targetFramework="net452" />
<package id="Ninject.Web.WebApi" version="3.2.3.0" targetFramework="net452" />
<package id="Ninject.Web.WebApi.WebHost" version="3.2.3.0" targetFramework="net452" />