Does Simple Injector supports MVC 4 ASP.NET Web API?

Question

I am new to Simple Injector IOC container. I will start working in a project which will require a Multi-tenant ASP.NET MVC implementation using MVC 4 ASP.NET Web API.

My question is: Does Simple injector support MVC 4 ASP.NET Web API? Reading simple injector documentation like this makes references to MVC 3 and I would like to know if MVC 4 also is supported.

Answer 1

Does Simple injector IOC support MVC 4 ASP.NET Web API?

It has currently no support for MVC4 Web API, but support will be added in the future. The integration guide will be updated when this happens.

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UPDATE : Web API support has been added to Simple Injector 2.5.

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In the meantime, you can create your own System.Web.Http.Dependencies.IDependencyResolver implementation for the Simple Injector. Below is the implementation for working with Web API in a IIS hosted environment:

public class SimpleInjectorHttpDependencyResolver : 
    System.Web.Http.Dependencies.IDependencyResolver
{
    private readonly Container container;

    public SimpleInjectorHttpDependencyResolver(
        Container container)
    {
        this.container = container;
    }

    public System.Web.Http.Dependencies.IDependencyScope
        BeginScope()
    {
        return this;
    }

    public object GetService(Type serviceType)
    {
        IServiceProvider provider = this.container;
        return provider.GetService(serviceType);
    }

    public IEnumerable<object> GetServices(Type serviceType)
    {
        IServiceProvider provider = this.container;
        Type collectionType = typeof(IEnumerable<>).MakeGenericType(serviceType);
        var services =(IEnumerable<object>)this.ServiceProvider.GetService(collectionType);
        return services ?? Enumerable.Empty<object>();
    }

    public void Dispose()
    {
    }
}

This implementation implements no scoping, since you need to use the Per Web Api Request lifetime for implementing scoping inside a web hosted environment (where a request may end on a different thread than where it started).

Because of the way Web API is designed , it is very important to explicitly register all Web API Controllers. You can do this using the following code:

var services = GlobalConfiguration.Configuration.Services;
var controllerTypes = services.GetHttpControllerTypeResolver()
    .GetControllerTypes(services.GetAssembliesResolver());

foreach (var controllerType in controllerTypes)
{
    container.Register(controllerType);
}

You can register the SimpleInjectorHttpDependencyResolver as follows:

// NOTE: Do this as last step, after registering the controllers.
GlobalConfiguration.Configuration.DependencyResolver = 
    new SimpleInjectorHttpDependencyResolver(container); 

Answer 2

The short answer is: yes, it works. Below is the code snippet that works for my project with both Web API and MVC4 controllers (partially based on Steven's response above):

var container = new Container();

//Register you types in container here

container.RegisterMvcControllers(Assembly.GetExecutingAssembly());
container.RegisterMvcAttributeFilterProvider();

var controllerTypes =
from type in Assembly.GetExecutingAssembly().GetExportedTypes()
where typeof(ApiController).IsAssignableFrom(type)
where !type.IsAbstract
where !type.IsGenericTypeDefinition
where type.Name.EndsWith("Controller", StringComparison.Ordinal)
select type;

foreach (var controllerType in controllerTypes)
{
    container.Register(controllerType);
}

container.Verify();
DependencyResolver.SetResolver(new SimpleInjectorDependencyResolver(container));

To access your types in the API controllers you could use the following code snippet:

DependencyResolver.Current.GetService<InterfaceName>()