Swift - initialize UIViewController

Question

I've got problem with init my parameters in UIViewController. I've got a class:

class ViewController: UIViewController {
   @IBOutlet var cardButtons: Array<UIButton>

   var flipCount = 0
   var game: CardMatchingGame
   var backCardImage: UIImage
   var frontCardImage: UIImage

   required init(coder aDecoder: NSCoder) {
      self.backCardImage = UIImage(named: "back")
      self.frontCardImage = UIImage(named: "front")
      self.game = CardMatchingGame(count: cardButtons.count, deck: createDeck())

      super.init(coder: aDecoder)
  }

  @IBAction func touchCardButton(sender: UIButton) {
      var cardButtonsArray = cardButtons as NSArray
      var chosenButtonIndex = cardButtonsArray.indexOfObject(sender)
      game.chooseCardAtIndex(chosenButtonIndex)
  }

  func createDeck() -> Deck {
      return PlayingCardDeck()
  }

}

but I've got a error in

count: cardButtons.count >> Variable 'self.cardButtons' used before being initialized/Property 'self.cardButtons' not initialized at super.init call

and

deck: createDeck() >> 'self' used before super.init call

How can I fix this to got properly initialized UIViewController?

Thank you for your help.

Answer 1

You want to override awakeFromNib and access the outlet there, not in the initialiser.

"The nib-loading infrastructure sends an awakeFromNib message to each object recreated from a nib archive, but only after all the objects in the archive have been loaded and initialized. When an object receives an awakeFromNib message, it is guaranteed to have all its outlet and action connections already established."

So I suggest something like:

class ViewController: UIViewController {
   @IBOutlet var cardButtons: Array<UIButton>!

   var flipCount = 0
   var game: CardMatchingGame!
   var backCardImage: UIImage
   var frontCardImage: UIImage

   required init(coder aDecoder: NSCoder) {
      self.backCardImage = UIImage(named: "back")
      self.frontCardImage = UIImage(named: "front")

      super.init(coder: aDecoder)
  }

  override func awakeFromNib() {
      super.awakeFromNib()
      self.game = CardMatchingGame(count: cardButtons.count, deck: createDeck())
  }

  @IBAction func touchCardButton(sender: UIButton) {
      var cardButtonsArray = cardButtons as NSArray
      var chosenButtonIndex = cardButtonsArray.indexOfObject(sender)
      game.chooseCardAtIndex(chosenButtonIndex)
  }

  func createDeck() -> Deck {
      return PlayingCardDeck()
  }
}