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 with spaces

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
    if string == " " { return true }
    if let _ = string.rangeOfCharacter(from: CharacterSet.letters){
        return true
    }
    return false
}