Injected property wrapper for better usage

[gf0x]

I'd like to suggest a feature that I was lacking: property wrapper for the DI. Finally thanks to Swift 5 updates it was possible to implement.

Let me explain the problem it solves in a few words.
If we have viewModel injected in UIViewController, we usually want it to be private to provide some kind of encapsulation.

class MyViewController: UIViewController {

private var viewModel: MyViewModel!

...
}

However, it's not possible to do that if we resolve it outside the UIViewController which is especially true if we use SwinjectStoryboard and resolve this value in the storyboardInitCompleted.

So we usually fall back to this:

var viewModel: MyViewModel!

With the use of my approach we can easily write:

@Injected private var viewModel: MyViewModel!

This gives us the ability to preserve encapsulation, inject property without problems and keep our code clear and nice.

Moreover, we can specify the container for injection to be resolved from and/or name of the dependency.

@Injected(SwinjectStoryboard.defaultContainer, "myDependency") private var viewModel: MyViewModel!

I feel really bad about having to write so many inits instead of one but it's the only way to deal with this swift bug

I'm looking forward to see this in future releases!

[kleber11]

Thanks man! Finally I've got better solution for such problem!