Alert doesn't pop up when expected - ios

Question

I want to change a label's text.
#IBAction func renameLabel(_ sender: UIButton) {
let labelTextToBeChanged = "some text"
let changedLabelText = changeLabeltext(text: labelTextToBeChanged!)
// Do something
print("changedLabelText: \(changedLabelText)")
}
The function changeLabeltext() contains an alert controller, as shown below.
I expect that after the call of changeLabeltext(text: labelTextToBeChanged!) an alert window pops up and that after modifying the text the new text ist assigned to changedLabelText and is printed out.
However, after the function call an empty text ist printed out and then, after exit the IBAction function, the alert window pops up. What I am doing wrong?
func changeLabeltext(text: String) -> String{
var inputTextField:UITextField?
// Create the controller
let alertController = UIAlertController(
title: "Ändere Projekt- oder Versionsname",
message: "",
preferredStyle: .alert)
// Create a textfield for input
alertController.addTextField{
(textField: UITextField!) -> Void in
textField.placeholder = text
inputTextField = textField
}
// Create the actions
let saveAction = UIAlertAction(
title: "Speichern",
style: .default,
handler: { (action: UIAlertAction!) -> Void in
inputTextField = alertController.textFields![0]
inputTextField?.text = text
})
let cancelAction = UIAlertAction(
title: "Abbruch",
style: .default,
handler: { (action: UIAlertAction!) -> Void in
})
// Add the actions to the UIAlertController
alertController.addAction(saveAction)
alertController.addAction(cancelAction)
present(alertController, animated: true, completion: nil)
return (inputTextField?.text)!
}

Answer 1

inputTextField is empty when this line is executed return (inputTextField?.text)!. All you have to do is change your saveAction, and from that action you coud use the text:
let saveAction = UIAlertAction(
title: "Speichern",
style: .default,
handler: { (action: UIAlertAction!) -> Void in
inputTextField = alertController.textFields![0]
inputTextField?.text = text
use(newText: text) //Or do whatever you want with the text
})
and declare the function that uses that text:
func use(NewText: String) {
//Do whatever with the new text
}
And there is no need to return a string from changeLabeltext:
func changeLabeltext(text: String) {
//...
}