title: UINavigationController and viewWillDisappear
body: <p>So I have a UINavController in my app and am trying to execute a method when the user presses the back button.  I have searched everywhere and can only find bits and pieces that don't really make sense out of context.  </p>
  
  <p>Is there a way to implement some sort of check that catches when the user presses the back button to dismiss the current view?  (the viewWillDisappear method for the view being popped never gets called for some reason.  I did read that it doesn't unless you forward that call?)  Does that sound right, and does anyone have any ideas or suggestions?  Thanks in advance.</p>