Swift Xcode 6: How do I use multiple functions in one statement? - xcode

Question

I am a newcomer in xcode and swift, and I am having a problem with using two IBActions to allow a button to be enabled. I have 2 text fields, and I have a button that is disabled. I want the button to be enabled when both of the text fields are filled in. How can I do this? So far I have declared two functions with IBActions for the two text fields:
#IBAction func yourWeightEditingDidBegin(sender: AnyObject) {
}
#IBAction func calorieNumberEditingDidBegin(sender: AnyObject) {
}
Thanks!

Answer 1

One way is to use the UITextFieldDelegate function instead of IBOutlets:
func textFieldShouldReturn(textField: UITextField!) -> Bool {
textField.resignFirstResponder()
if yourWeight.text != "" && calorieNumber.text != "" {
button.enabled = true
}
return true
}

Answer 2

I, too, implement UITextFieldDelegate, but I use shouldChangeCharactersInRange. This way, the status of that button changes as the user types:
If dealing with only two text fields, it looks like:
func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
// get the value this text field will have after the string is replaced
let value: NSString = (textField.text as NSString).stringByReplacingCharactersInRange(range, withString: string)
// get the value of the other text field
let otherValue = textField == yourWeight ? calorieNumber.text : yourWeight.text
// only enable done if these are both non-zero length
doneButton.enabled = (value != "" && otherValue != "")
return true
}
Clearly, for this to work, you must specify the delegate for both of those text fields (either in IB or programmatically). I also generally marry the above with the "auto-enable return key" option for the text fields, too.

Answer 3

You don't. Instead, try something like this
var weightIsFilled = false
var calorieNumberIsFilled = false
#IBAction func yourWeightEditingDidBegin(sender: AnyObject) {
if valueOfWeightTextFieldIsValid() {
self.weightIsFilled = true
}
if self.weightIsFilled && self.calorieNumberIsFilled {
self.enableButton()
}
}
#IBAction func calorieNumberEditingDidBegin(sender: AnyObject) {
if valueOfCalorieNumberTextFieldIsValid() {
self.calorieNumberIsFilled = true
}
if self.weightIsFilled && self.calorieNumberIsFilled {
self.enableButton()
}
}
You also may want to be using IBAction functions that are called when the textfield's value changes, not when editing begins on it.