CODEWITHSUNDEEP
asp.netasp.net-mvcasp.net-web-apidependency-injectionunity-container
Amir Popovich
Amir Popovich

Reputation: 29836

When does the IDependencyResolver start his job in the asp.net lifecycle?

I'm building a new asp.net webapi application that may use asp.net MVC controllers later.

I'm going to use Unity as an IOC + Lifetime resolver to handle my objects.

I want all my types to be resolved in one place.

I've read about the IDependencyResolver which provides a service-locator(I know it's an anti-pattern) and it seems to fit my goals.

I've tried to find the "scope" of this IDependencyResolver and couldn't.
What I did see is that's he's under System.Web.Mvc - that kinda made me think about his "scope".

When does he "start" his job in the asp.net application lifecycle?
Will he resolve HttpModules as well? Or does he "kick in"

My Global.asax code will look something like this:

ApplicationUnityResolver resolver = new ApplicationUnityResolver(ApplicationContainer._container, DependencyResolver.Current);
GlobalConfiguration.Configuration.DependencyResolver = resolver;
DependencyResolver.SetResolver(resolver);

My ApplicationUnityResolver is:
System.Web.Mvc.IDependencyResolver and System.Web.Http.Dependencies.IDependencyResolver

Upvotes: 0

Views: 480

Answers (1)

Spock
Spock

Reputation: 6992

I think it is fairly early in the MVC pipeline the DependencyResolver get instantiated. MVC framework internally use the DependencyResolver. As you know the DependencyResolver finds and create instance of Controllers, during the Controller creation. Which is right after the IRouteHandler i.e MvcRouteHandler get invoked - fairly early in the life cycle.

But it is well after the HttpModules get created, I think you are out of luck using the DependencyResolver to register HttpModules.

I don't think you cannot customize the scope of the IDependencyResolver. It is just Service Locator type container which helps you to plugin your own dependency resolution mechanism.

Yes IDependencyResolver is an anti-pattern and I personally don't like it. Actually Mark Seemann has a really good article on the IDependencyResolver. I'm sure this would point you to the right direction.

You better off using the Composition Root pattern to register dependencies in a single location.

Upvotes: 1

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