UITextField delegate method not called - ios

Question

I am presenting an alert with UITextfield, but its delegate methods are not getting called. What wrong I might be doing. I am using the below code to show the alert with textfield.
func takePasscodeToEnableTouch(){
self.passcodeInputOperationType = .EnableTouchID
alertControllerPassCodeEntry = UIAlertController(title: "", message: "Enter Passcode to enable the Touch Id.", preferredStyle: UIAlertControllerStyle.Alert)
let cancelAction = UIAlertAction(title: "Cancel", style: UIAlertActionStyle.Cancel) { (action) -> Void in
}
alertControllerPassCodeEntry!.addAction(cancelAction)
alertControllerPassCodeEntry!.addTextFieldWithConfigurationHandler { (txtField) -> Void in
txtField.placeholder = "Enter passcode"
txtField.delegate = self
txtField.tag = TextFieldTag.EnterPassCode
txtField.keyboardType = UIKeyboardType.NumbersAndPunctuation
txtField.accessibilityIdentifier = "PassCode"
txtField.secureTextEntry = true
txtField.addTarget(self, action:"textFieldDidChange:", forControlEvents: UIControlEvents.EditingChanged)
}
let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
appDelegate.window?.rootViewController?.presentViewController(alertControllerPassCodeEntry!, animated: true, completion: nil )
}
And the textField delegate methods are :
func textFieldShouldBeginEditing(textField: UITextField) -> Bool
{
return true
}
func textFieldDidBeginEditing(textField: UITextField) // became first responder
{
}
func textFieldShouldEndEditing(textField: UITextField) -> Bool
{
return true
}
func textFieldDidEndEditing(textField: UITextField)
{
}
func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool
{
var isLimitExist: Bool
var accessIndentifier: String
if let str = textField.accessibilityIdentifier
{
accessIndentifier = str
}
else
{
accessIndentifier = ""
}
//checkFieldLimit function is used to check the limit of text and restrict
isLimitExist = UIUtils.checkFieldLimit(accessIndentifier, stringToMatch: textField.text!, rangeLength: range.length, stringLength: string.characters.count)
if !isLimitExist
{
return false
}
return true
}

Answer 1

Ok, so with information from the comments, everything seems clear now. To recap, you call the method showing the alert like this :
#IBAction func swtchTouchAction(sender: UISwitch) {
if sender.on {
let passCodeManager = PasscodeManager()
passCodeManager.delegate = self
passCodeManager.takePasscodeToEnableTouch()
} else {
let passCodeManager = PasscodeManager()
passCodeManager.delegate = self
passCodeManager.authenticatePasscodeToDisalbeTouch()
}
}
Now, you don't retain (meaning - assign to a strong property) the passCodeManager anywhere in here. This means, that at the end of this method this object gets destroyed (thanks to ARC - Automatic Reference Counting). One may think that it would get retained because you assigned it as a delegate of the text field, but delegates are weak proeprties 99.99% of time - this means that they don't bump the retain count of objects assigned to them.
To solve your immediate issue you should make a property in your class in which you have swtchTouchAction method and change your code like this :
var passCodeManager: PasscodeManager?
#IBAction func swtchTouchAction(sender: UISwitch) {
if sender.on {
self.passCodeManager = PasscodeManager()
self.passCodeManager?.delegate = self
self.passCodeManager?.takePasscodeToEnableTouch()
} else {
self.passCodeManager = PasscodeManager()
self.passCodeManager?.delegate = self
self.passCodeManager?.authenticatePasscodeToDisalbeTouch()
}
}
This will be enough to retain your passcode manager.
I'd also suggest you read up on how memory management is done in Swift.