how to handle iPhone calendar event changes when EventKitUI screens are being displayed?

The EventKit (programming guide) covers how to handle things in your app code when the underlying iPhone calendar event data changes, via observers. ok.

What do you do 开发者_StackOverflow社区however if you are in the middle of displaying an Apple EventKitUI screen (i.e. not your own code) as part of your application? How do you invalidate/give a user message, or auto-refresh the data, if the underlying event data changes. For example if you jump out of your app, go to calendar make a change, then jump back into your app which is still at the EKUI "display" or "edit" event screen?

answer I got elsewhere is that these EKEvent views roll themselves back (based on pop'ing from the nav controller) automatically if the data becomes stale...