UITextField Changes Not Being Detected? - variables

Question

I have two flag properties that should change when a text field contains an integer, and I have IBActions, when the text field editing ends, that change the flags. When both of the variables are true, those methods should enable a button. I ran the iOS simulator, but the button isn't enabling. I also declared the text field delegate for both the text fields.
I am new to swift, so please be clear with your answer. Also, I haven't set any breakpoints. Here's the code for what I have so far:
var yourWeightFilled = false
var calorieNumberFilled = false
func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
// Find out what the text field will be after adding the current edit
let text = (textField.text as NSString).stringByReplacingCharactersInRange(range, withString: string)
if textField == yourWeightTextField {
yourWeightFilled = text.toInt() != nil
} else if textField == calorieNumberTextField {
calorieNumberFilled = text.toInt() != nil
}
return true
}
#IBAction func yourWeightEditingDidEnd(sender: AnyObject) {
if self.yourWeightFilled && self.calorieNumberFilled {
self.calculateButton.enabled = true
}
yourWeightTextField.resignFirstResponder()
}
#IBAction func calorieNumberEditingDidEnd(sender: AnyObject) {
if self.yourWeightFilled && self.calorieNumberFilled {
self.calculateButton.enabled = true
}
calorieNumberTextField.resignFirstResponder()
}

Answer 1

UITextField is a subclass of UIControl and thus needs to have action methods registered to be called in response to control events. You do that with the addTarget(_:action:forControlEvents:) method.
For example:
weightField.addTarget(self, action:"yourWeightEditingDidEnd:", forControlEvents:.EditingDidEnd);
Would work in your case to call your action method yourWeightEditingDidEnd() when the user finishes editing the text field. This assumes your field property is named weightField. A good place for this code is in your view controller's viewDidLoad() method.
There is one more important step. You appear to be implementing UITextFieldDelegate, which is good because you also need a textFieldShouldReturn(textField:) -> Bool method that returns true and resigns the text field as first responder. Example:
func textFieldShouldReturn(textField: UITextField) -> Bool
{
textField.resignFirstResponder();
return true;
}
This in turn causes the .EditingDidEnd control event to fire and the action method you registered to be called.