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

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.