UITextfield keyboard with only alphabet, no numbers, no caps, no spacebar?

Question

I want the keyboard for the UITextfield to only have a-z, no numbers, no special characters (!@$!@$@!#), and no caps. Basicly I am going for a keyboard with only the alphabet.

Answer 1

Swift 3 solution

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {

     let characterSet = CharacterSet.letters

     if string.rangeOfCharacter(from: characterSet.inverted) != nil {
         return false      
     }
     return true
}