title: textField:shouldChangeCharactersInRange:replacementString: in subclass
body: <p>I've subclassed a UITextField and I'd like to use a method similar to <code>textField:shouldChangeCharactersInRange:replacementString:</code> inside the subclass to get notified when a character is typed and if necessary block the change, but avoid setting the fields delegate to itself.</p>
  
  <p>I've found if I override <code>keyboardInput:shouldInsertText:isMarkedText:</code> and <code>keyboardInputShouldDelete:</code> I can get the desired effect, unfortunately these methods are private and anything using the class won't make it through the App Store submission process.</p>
  
  <p>Anyone know of a public method that achieves the same thing and doesn't require the field being its own delegate?</p>
  
  <p><strong>UPDATE:</strong></p>
  
  <p>I went with the suggestion of creating a separate object just to be the delegate, which itself can have a delegate to forward messages to.</p>