How to toggle button text and colour in Xcode 10 - UIControl.State.normal missing

Question

I'm new to swift and watching a tutorial on how to toggle the background colour and text of a button when it is clicked.

The problem is, the background colour and text do not change when the button is clicked.

The function, which is identical to the instructor's and works on his laptop is :

func flipCard(withEmoji emoji: String, on button: UIButton){
    if button.currentTitle == emoji{
     button.setTitle("", for UIControl.State.normal)
     button.backgroundColor = UIColor.red
    }else{
    button.setTitle(emoji, for UIControl.State.normal)
    button.backgroundColor = UIColor.white
    }

}

I call the function with:

@IBAction func callFlip(_ sender:UIButton){
   flipcard(withEmoji: "em", on: sender)
}

I have searched for a solution but they all seem to refer to older versions of Xcode and swift.

Nevertheless i have tried to to replace

button.setTitle(emoji, for: UIControl.State.normal)

with

button.setTitle(emoji, for: UIControl.State(rawValue:UInt(0))) and

button.setTitle(emoji, for: []) as suggested here with the same result :( . How can i get this to work please?

Im using Xcode 10.1 (10B61). Does the version of Xcode matter?

cheers

Answer 1

Tested this, with a button with title FlipColor and get the inverting effect.

 func flipCard(withEmoji emoji: String, on button: UIButton){
      if button.currentTitle == emoji {
           button.setTitle("", for: UIControl.State.normal)
           button.backgroundColor = UIColor.red
           button.tintColor = .yellow
      }else{
           button.setTitle(emoji, for: UIControl.State.normal)
           button.backgroundColor = UIColor.white
           button.tintColor = .red
      }

 }

 @IBAction func flipMyColor(_ sender: UIButton) {

      flipCard(withEmoji : "FlipColor", on: sender)
 }