intercept keyboard events in swift for iOS

var keys = [UIKeyCommand]()

override func viewDidLoad() {
    super.viewDidLoad()
    //configureGameControllers()

    for digit in "abcdefghijklmnopqrstuvwxyz"
    {
        keys.append(UIKeyCommand(input: String(digit), modifierFlags: nil, action:  Selector("keyPressed:")))
    }
}

override func canBecomeFirstResponder() -> Bool {
    return true
}

override var keyCommands: [AnyObject]? {
    get {
        return keys
    }
}


func keyPressed(command: UIKeyCommand) {
    println("user pressed \(command.input)")
}

#17: UIKeyCommand

Tuesday June 16th, 2015
iOS has had support for hardware keyboard shortcuts for a while now. New in iOS 9, Apple has made some great improvements to how apps can take advantage of them. Your app can now register keyboard shortcuts per view controller, and all currently valid shortcuts will be neatly
summarized when the user brings up the new keyboard shortcuts view.
Wiring up a new keyboard shortcut in this system couldn't be easier. Just define a new function, create a new UIKeyCommand and then call addKeyCommand on your view controller:
// inside some UIViewController subclass:

override func viewDidLoad() {
super.viewDidLoad()

let shortcut = UIKeyCommand(
input: "n",
modifierFlags: UIKeyModifierFlags.Command,
action: "createNewFile:"
)

addKeyCommand(shortcut)
}

func createNewFile(command: UIKeyCommand) {
// do the thing
}