REST 4.0 & Ninject.Extensions.Wcf 2.3 NullReferenceException - web-services

Question

I am trying to make a simple REST Service with .NET 4.0 that uses ninject to inject any dependencies for the service.
This is what my service looks like currently:
[ServiceContract]
[AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Required)]
[ServiceBehavior(InstanceContextMode = InstanceContextMode.PerCall)]
public class ReportService
{
private readonly ReportManager _reportManager;
public ReportService(ReportManager reportManager)
{
_reportManager = reportManager;
}
[WebInvoke(UriTemplate = "GetReports", Method = "GET")]
public List<ReportDTO> GetReports()
{
var reports = _reportManager.GetReports();
return reports.ToList();
}
}
This is my global.asax:
public class Global : NinjectHttpApplication
{
void Application_Start(object sender, EventArgs e)
{
RegisterRoutes();
}
private void RegisterRoutes()
{
RouteTable.Routes.Add(new ServiceRoute("ReportService", new NinjectWebServiceHostFactory(), typeof(ReportService)));
}
protected override IKernel CreateKernel()
{
return new StandardKernel(new ServiceModule());
}
}
And my ServiceModule:
public class ServiceModule : NinjectModule
{
public override void Load()
{
Bind<IFRSDbContext>().To<FRSDbContext>().InRequestScope();
Bind<IDatabaseFactory>().To<DatabaseFactory>().InRequestScope();
Bind<IUnitOfWork>().To<UnitOfWork>().InRequestScope();
Bind<IReportRepository>().To<ReportRepository>();
Bind<ReportManager>().ToSelf();
Bind<ReportService>().ToSelf();
}
}
I keep getting the following exception when I try to run my service:
Description: An unhandled exception occurred during the execution of
the current web request. Please review the stack trace for more
information about the error and where it originated in the code.
Exception Details: System.NullReferenceException: Object reference not
set to an instance of an object.
Source Error:
An unhandled exception was generated during the execution of the
current web request. Information regarding the origin and location of
the exception can be identified using the exception stack trace below.
Stack Trace:
[NullReferenceException: Object reference not set to an instance of an object.]
System.Web.HttpApplication.RegisterEventSubscriptionsWithIIS(IntPtr appContext, HttpContext context, MethodInfo[] handlers) +222
System.Web.HttpApplication.InitSpecial(HttpApplicationState state, MethodInfo[] handlers, IntPtr appContext, HttpContext context) +194
System.Web.HttpApplicationFactory.GetSpecialApplicationInstance(IntPtr appContext, HttpContext context) +339
System.Web.Hosting.PipelineRuntime.InitializeApplication(IntPtr appContext) +253
[HttpException (0x80004005): Object reference not set to an instance of an object.]
System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +9079228
System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +97
System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +256
EDIT
I've updated to the most current version of my Service.. I am using Ninject 2.3 and Ninject.Extensions.Wcf 2.3 from here but am still having no luck.. what am I doing wrong? I've followed everything from the WcfTimeService example except that I am using a REST service and not a .svc Wcf service...

Answer 1

You shouldn't call Application_Start. Instead override OnApplicationStarted

Answer 2

After downloading the sources of Ninject.Web.Common and Ninject.Extensions.Wcf I was able to track down the issue.
In order to get this to work without a *.svc file you need to call the Application_Start() method of the NinjectHttpApplication at the end of the Application_Start() in Global.asax.cs file, like so:
public class Global : NinjectHttpApplication
{
void Application_Start(object sender, EventArgs e)
{
RegisterRoutes();
Application_Start(); // added call
}
private void RegisterRoutes()
{
RouteTable.Routes.Add(new ServiceRoute("ReportService", new NinjectWebServiceHostFactory(), typeof(ReportService)));
}
protected override IKernel CreateKernel()
{
return new StandardKernel(new ServiceModule());
}
}
Without doing this, the Kernel never gets created and therefore that is what causes the NullReferenceException. After I did this everything started working perfectly.