Daniel Hoelbling-Inzko talks about programming
Named dependency lookup – Pandora
One rather essential feature for a DI container is to be able to lookup components by some key. For example retrieving a specific IController class based on the controller name specified by the request.
So the usual use case for the above looks like this:
var store = new ComponentStore();
store.Add<IRepository, MemoryRepository>("memory.repository");
store.Add<IRepository, SqlRepository>("db.repository");
var container = new PandoraContainer(store);
var service = container.Resolve<IRepository>("db.repository");
Now, there is another thing too: What if I want one controller to use one special repository out of the registered ones:
var store = new ComponentStore();
store.Add<IRepository, SqlRepository>("db.repository");
store.Add<IRepository, MemoryRepository>("memory.repository");
store.Add<Controller, Controller>()
.Parameters("repository").Eq("memory.repository");
var container = new PandoraContainer(store);
var controller = container.Resolve<Controller>();
Well, yes Pandora can do those kinds of things too.
If you know Windsor’s Fluent interface .Parameters().Eq() may sound familiar to you. That’s intentionally. I like the Windsor Fluent syntax.
What I really underestimated was how to do the fluent interface. It’s not terribly hard, but it’s takes some tinkering ;).
You can find the source to Pandora at the project website on Bitbucket.
My Photography business
Projects
