How do I use a subclass of NSDocumentController in XCode 4?

Question

I am currently in the process of trying to teach myself Cocoa development. Toward this end, I purchased a mostly-excellent book, Cocoa Recipes for Mac OS X: Vermont Reci

Answer 1

You can subclass easily in Swift 3:

class AppDelegate: NSObject {
    let docController = DocController()
}

class DocController: NSDocumentController {
}