Setter / property injection in Unity without attributes

Question

I am working on a project where the Unity framework is used as the IoC container. My question relates to injecting an optional dependency (in this case a logger) into several classes using property- or setter injection.

I do not want to clutter the constructors of all my classes with these optional dependencies, but I cannot find a good way to handle this in Unity. The way you would do this is, according to the MSDN documentation, by adding an attribute to the property:

private ILogger logger; 

[Dependency]
public ILogger Logger
{
get { return logger; }
  set { logger = value; }
}

I find this very ugly. In StructureMap one could do the following to set all properties of a given type:

SetAllProperties(policy => policy.OfType<ILog>());

Does anyone know if it is possible to do something similar in Unity?

Edit:

Kim Major suggests using this approach which can also be achieved through code.

I would be interested in examples of how to do this automatically for all matching properties.

Answer 1

The following walkthrough shows one way of doing it through configuration. You can of course wire it through code as well. http://aardvarkblogs.wordpress.com/unity-container-tutorials/10-setter-injection/

Answer 2

I don't like those attributes also

You can do all using the Configure method of the unity container:

First register the type

unityContainer.RegisterType<MyInterface,MyImpl>(
                     new ContainerControlledLifetimeManager());

If you have multiple constructors you'll have to to this so Unity invokes the parameterless constructor (if none set Unity will go for the fattest one)

unityContainer.Configure<InjectedMembers>()
                            .ConfigureInjectionFor<MyImpl>(
                                new InjectionConstructor());

Setting property dependency

unityContainer.Configure<InjectedMembers>()
                    .ConfigureInjectionFor<MyImpl>(
                         new InjectionProperty(
                             "SomePropertyName",
                                new ResolvedParameter<MyOtherInterface>()));

Configuring method dependency

unityContainer.Configure<InjectedMembers>()
                    .ConfigureInjectionFor<MyImpl>(
                        new InjectionMethod(
                            "SomeMethodName",
                            new ResolvedParameter<YetAnotherInterface>()));

Answer 3

You could try this:

this code in MyClass

[InjectionMethod]
public void Initialize(
                 [Dependency] ILogger logger

and then calling it by:

unitycontainer.BuildUp<MyClass>(new MyClass());

unity will then call Initialize method with the dependency from the container and then u can save it in a private variable in MyClass or something...