UITextField character restriction

Question

I have a UITextField and I have it set up so you can only enter 8 characters into it. The problem is, once the 8th character is entered, the user can not use the delete key. How do I allow the delete key on the keyboard to be used while I have 8 characters entered in my textfield?

Here is my code:

   func textField(textField: UITextField!,shouldChangeCharactersInRange range: NSRange, replacementString string: String!) -> Bool {
        var shouldChange = false
        if countString(textField.text) < 8 {
            shouldChange = true
        }

        return shouldChange
}

Note: countString is a private function that counts the number of characters in a string

Answer 1

What you need is to not check if there are less than 8 chars, but whether or not your existing string plus the input length is larger than 8.

func textField(textField: UITextField!,shouldChangeCharactersInRange range: NSRange, replacementString string: String!) -> Bool {
    NSUInteger newLength = countString(textField.text)+ countString(string) - range.length;
    return !(newLength > 8)
}