SWIFT: Extension for UITextField that doesn't accept whitespace as input

Question

I know shouldChangeTextInRange method on UITextFieldDelegate can filter input on UITextField, it's ok if i only need to filter one UITextField. Now my problem is i have lot of UITextField that need to filter whitespace. And i don't want to implement shouldChangeTextInRange on every UIViewController that have UITextField in it. Is there anyway to make extension of the UITextField or other?

Answer 1

Actually this is quite simple, just subclass UITextField, add delegate to it, and implement the shouldChangeTextInRange there.

class CustomTextField: UITextField, UITextFieldDelegate {
  override func awakeFromNib() {
    super.awakeFromNib()

    delegate = self
  }

  func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
    if (string.rangeOfCharacterFromSet(.whitespaceCharacterSet()) != nil) {
      return false
    } else {
      return true
    }
  }
}