How to Ask for Initials for Game in Swift - swift

Question

I am making a game in Swift that records the high score and initials (similar to pinball records) and displays it on the game screen as labels. I am using the code below to record the high score and initials on my phone and update them. For the time being, this program will only be on my phone so I am not concerned about storing or updating data on a remote database.
What I don't know how to do (yet) is make a little popup asking the user to enter their initials on a keyboard when the quit button is pressed, if they have the current high score. Ideally, I want it to be able to only accept 3 characters and to update the initials label immediately, before the user is taken to a different view controller.
#IBOutlet weak var scoreLabel: UILabel!
#IBOutlet weak var highScoreLabel: UILabel!
#IBOutlet weak var highScoreInitialsLabel: UILabel!
var score : Int = 0
//Stores and sets high score initials
var oldHighScoreInitials : String = "AAA"
var highScoreInitials : String {
get {
return UserDefaults.standard.string(forKey: "highScoreInitials") ?? "AAA"
}
set {
UserDefaults.standard.set(newValue, forKey: "highScoreInitials")
}
}
//Stores and sets high score
var oldHighScore : Int = 0
var highScore : Int {
get {
return UserDefaults.standard.integer(forKey: "highScore")
}
set {
UserDefaults.standard.set(newValue, forKey: "highScore")
}
}
override func viewDidLoad() {
super.viewDidLoad()
//Updates high score and initials labels with stored highest score and associated initials
highScoreLabel.text = String(highScore)
highScoreInitialsLabel.text = String(highScoreInitials)
oldHighScore = highScore
oldHighScoreInitials = highScoreInitials
}
//Asks for initials if new high score, and segues to Main VC
#IBAction func quitButtonPressed(_ sender: AnyObject) {
if (score > highScore){
highScore = score
print("Ask for initials")
print("Game over, thanks for playing!"
print("Segue to Main VC")
}
else {
print("Game over, thanks for playing!")
print("Segue to Main VC")
}
}
Thank you very much to anybody that offers assistance or advice.

Answer 1

Here you go, pretty simple using UIAlertViewController:
//Asks for initials if new high score, and segues to Main VC
#IBAction func quitButtonPressed(_ sender: AnyObject) {
if (score > highScore){
highScore = score
let alert = UIAlertController(title: "NEW HIGH SCORE", message: "Please enter your initials", preferredStyle: .alert)
alert.addTextField(configurationHandler: configurationTextField)
alert.addAction(UIAlertAction(title: "DONE", style: .default, handler:{ (action) in
//First example of updating initials
guard alert.textFields![0].text?.characters.count != 0 else{
return
}
self.oldHighScore = self.highScore
self.oldHighScoreInitials = alert.textFields![0].text
//Segue to Main VC
}))
present(alert, animated: true, completion: nil)
}
else {
print("Game over, thanks for playing!")
print("Segue to Main VC")
}
}
func configurationTextField(textField: UITextField!){
textField.delegate = self
textField.textAlignment = .center
textField.placeholder = "_ _ _"
}
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
guard let text = textField.text else { return true }
let count = text.count + string.count - range.length
return count <= 3
}
//Second example of updating initials
func textFieldDidEndEditing(_ textField: UITextField) {
oldHighScore = highScore
oldHighScoreInitials = textField.text
}
And finally your controller should conform to the UITextFieldDelegate protocol:
class yourController: UIViewController, UITextFieldDelegate

Answer 2

After working with Arie Pinto, we determined that my segue was preventing the alert from working and was presenting an error stating that my program was attempting to present an alert whose view was not in the window hierarchy.
I programmed my segue by ctrl+dragging my quit button to a different view controller, without writing any code.
My solution to this will be to write in performSegue code in the quitButtonPressed function to allow the alert and initial update code to perform their actions before changing windows.