IoC in class library. Where to bootstrap

Question

I'm using a class library that can be reused by other components. In this class library I'm using unity for dependency injection. For this class library I create a test project. The caller also gets a test project. One thing I'm uncertain about is the location of the bindings. Should I incorporate this in the class library or should I do this from the calling application?

Answer 1

I know that an answer has been chosen, however I think a part of Unity is being overlooked. Since this was a specific Unity question I thought I point out the UnityContainerExtension base class that implements the IUnityContainerExtensionConfigurator. This is there for API library to extend to make it easy for the entry-point application who owns the Container to have an easy way to make sure your library gets registered with the Container correctly, and allows the API owner control of what gets registered and how.

This is used by the Microsoft Enterprise Libraries for this purpose.

I am going to use a Logging library as a simple:

public class LoggingUnityExtension : UnityContainerExtension
{
    protected override void Initialize()
    {
        Container.RegisterType<ILogger, Logger>(new ContainerControlledLifetimeManager());
    }
}

Then the entry-point application does this:

public class Bootstrapper : UnityBootstrapper
{
    protected override void ConfigureContainer()
    {
        base.ConfigureContainer();

        Container.AddNewExtension<EnterpriseLibraryCoreExtension>();
        Container.AddNewExtension<LoggingUnityExtension>();
        // ... 
    }

    // ...
}

Now they have registered Enterprise Library and the API for the Logging library. It's very simple for the entry-point application with this method which is what any library developer should have as a goal.