title: how to have Swift <BACK seque tap cause a func on the parent view to execute?
body: <p>When a user taps &lt;BACK on my 2nd view and it re-opens the 1st view, how can I make software run on the 1st view?</p>
  <p>&lt;BACK triggers didDisappear but I think at that points it's too early to execute a func on the 1st view.  And of course 1st view's ViewDidLoad doesn't execute a 2nd time.</p>