ServiceStack IOC Autowiring by Convention

A situation came up where we wanted to implement a convention to auto-wire many of our classes using ServiceStack IOC. Basically we wanted to eliminate the need to hard-code mappings over and over for every class in a bootstrap file.

For example we wanted to avoid this:

container.RegisterAutoWiredAs<MyType1,IMyType1>();
container.RegisterAutoWiredAs<MyType2,IMyType2>();
container.RegisterAutoWiredAs<MyType3,IMyType3>();
container.RegisterAutoWiredAs<MyType4,IMyType4>();
...

To achieve this we can use .net reflection to scan our assemblies and look for a special interface that represents classes we want to automatically inject. Then we can utilize the ServiceStack IOC method RegisterAutoWiredType to register the types during runtime.

Here's an example where IInjectable is the interface we use to identify which classes will be injected:

	//This class cannot be injected
	public class DummyManager
	{
	public void DoSomething(int id)
	{
	}
	}

view raw DummyManager.cs hosted with ❤ by GitHub

	public interface IInjectable
	{
	}

view raw IInjectable.cs hosted with ❤ by GitHub

	private static void RegisterCustomTypes(Container container)
	{
	//Get the Assembly Where the injectable classes are located.
	var assembly = Assembly.GetAssembly(typeof(IInjectable));
	//Get the injectable classes
	var types =assembly.GetTypes()
	.Where(m => m.IsClass && m.GetInterface("IInjectable") != null);
	//loop through the injectable classes
	foreach (var theType in types)
	{
	//set up the naming convention
	var className = theType.Name;
	var interfaceName = string.Concat("I", className);
	//create the interface based on the naming convention
	var theInterface = theType.GetInterface(interfaceName);
	//register the type with the convention
	container.RegisterAutoWiredType(theType, theInterface);
	}
	}

view raw Ioc.cs hosted with ❤ by GitHub

	//This class can be injected
	public interface ITestManager : IInjectable
	{
	void Execute(int id);
	}
	public class TestManager : ITestManager
	{
	public void Execute(int id)
	{
	throw new System.NotImplementedException();
	}
	}

view raw TestManager.cs hosted with ❤ by GitHub