StructureMap and ASP .Net Web API and .Net Framework 4.5

Question

Does the current version of StructureMap support ASP .Net Web API, MVC 4 and .NET Framework 4.5?

Answer 1

As outlined here, the web API uses a dependency resolver.

class StructureMapDependencyResolver : IDependencyResolver
{
    public IDependencyScope BeginScope()
    {
        return this; 
    }

    public object GetService(Type serviceType)
    {
        return ObjectFactory.GetInstance(serviceType);
    }

    public IEnumerable<object> GetServices(Type serviceType)
    {
        return ObjectFactory.GetInstances(serviceType);
    }

    public void Dispose()
    {
    }
}

And in your Global.asax.cs, include this line to register the dependency resolver:

GlobalConfiguration.Configuration.DependencyResolver = new StructureMapDependencyResolver();

Aside from that, the new Web API is very easy to use with IoC containers.

I haven't looked into it yet, but I believe the BeginScope method that I left blank can be used with child containers.

Edit:

The above implementation works great; in fact I prefer it over the alternative I'm about to tell you. This one will resolve any Type to the best of StructureMap's abilities and will throw errors whenever something goes wrong. I like seeing errors because they show me what I did wrong.

However, the API expects that GetService will return null if something goes wrong. So to be compliant with the API, this is the recommended implementation:

public object GetService(Type serviceType)
{
    if (serviceType.IsAbstract || serviceType.IsInterface)
        return ObjectFactory.TryGetInstance(serviceType);
    else 
        return ObjectFactory.GetInstance(serviceType);
}

The difference is that TryGetInstance only looks for types registered in the container and will return null if something goes wrong. serviceType.IsAbstract || serviceType.IsInterface is considered good enough of a check to decide which method to use. My original answer was intended to be straightforward and simple, but @PHeiberg points out in the comments here that it wasn't entirely "correct". Now that you have knowledge, use whatever seems best.