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asp.netfilterninjectscopes

Getting InRequestScope object in MVC Filters

As far as i know ASP MVC caches filters -> so they are not bound in request scope thus if i will ask ninject inside it for an instance of object i will get it in completly new scope.

In Web-Api I can use actionContext.Request.GetDependencyScope() where actionContext :: HttpActionContext to retrieve objects instances from request scope. I have been googling for some time and I cannot find anything similar in MVC. So the main qustion is :: Is there any way to retrieve object instances bound in request scope inside MVC filters?

Solution

  • I've had a look at the implementation of Ninject.web.mvcX InRequestScope(). It uses HttpContext.Current as scope object.

    That means, if you've got

    Bind<IFoo>().To<Foo>().InRequestScope();

    you can inject use

    IResolutionRoot.Get<IFoo>()

    basically anywhere/anytime at which HttpContext.Current is "valid".

    To bind the filter, you can use the ninject.web.mvcX nuget package and do:

    BindFilter<FooFilter>(FilterScope.Controller, 0)

    This allows you to use ctor-injection with the filter. Also see Ninject Wiki: Dependency Injection for Filters

    I'm not quite sure whether this changes when / how often filters are instanciated, but i don't think so. So in order to access an InRequestScope() object in your filter, you'll have to inject an IResolutionRoot or - even better - a factory (see ninject.extensions.factory) into your filter to create the object / object graph.