Formating phone number does not work fine - ios

Question

I am trying to format the User input phone number. I have implemented this:
import UIKit
class ViewController: UIViewController {
var phoneNumberTextField : UITextField?
var docController: UIDocumentInteractionController?
override func viewDidLoad() {
super.viewDidLoad()
phoneNumberTextField = UITextField(frame: CGRectMake(10, 150, 100, 50))
phoneNumberTextField?.backgroundColor = UIColor.brownColor()
self.view.addSubview(phoneNumberTextField!)
}
func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool
{
if (textField == phoneNumberTextField)
{
let newString = (textField.text! as NSString).stringByReplacingCharactersInRange(range, withString: string)
let components = newString.componentsSeparatedByCharactersInSet(NSCharacterSet.decimalDigitCharacterSet().invertedSet)
let decimalString = components.joinWithSeparator("") as NSString
let length = decimalString.length
let hasLeadingOne = length > 0 && decimalString.characterAtIndex(0) == (1 as unichar)
if length == 0 || (length > 10 && !hasLeadingOne) || length > 11
{
let newLength = (textField.text! as NSString).length + (string as NSString).length - range.length as Int
return (newLength > 10) ? false : true
}
var index = 0 as Int
let formattedString = NSMutableString()
if hasLeadingOne
{
formattedString.appendString("1 ")
index += 1
}
if (length - index) > 3
{
let areaCode = decimalString.substringWithRange(NSMakeRange(index, 3))
formattedString.appendFormat("(%#)", areaCode)
index += 3
}
if length - index > 3
{
let prefix = decimalString.substringWithRange(NSMakeRange(index, 3))
formattedString.appendFormat("%#-", prefix)
index += 3
}
let remainder = decimalString.substringFromIndex(index)
formattedString.appendString(remainder)
textField.text = formattedString as String
return false
}
else
{
return true
}
}
}
From Here. When I run the app and I start adding numbers nothing happens. Brackets and hypens do not appear. I want to convert (197)-444-4444 to 1974444444.
What is wrong here?

Answer 1

You dont seems to have set delegate for your textfield:
phoneNumberTextField.delegate = self
And your viewcontroller doesnt seems to conform the UITextFieldDelegate like:
class ViewController: UIViewController, UITextFieldDelegate {
Also, it would never be nil so just change it to var phoneNumberTextField : UITextField!