How to handle completion of system UIAlertController in iOS?
<p>So I know how to create a <code>UIAlertController</code> and set its completion handler. But is there a way to control what happens when a system deployed alert is displayed?</p>

<p>My situation is that when the user clicks the restore purchases button in my app, I start a <code>UIActivityIndicatorView</code>. If the user signs in and the purchases are restored, I can call code to make the activity wheel stop spinning in my Purchase Observer, but if cancel is clicked I don't have a way to stop the wheel and it continues to spin.</p>

<p>Anyone know of a solution?</p>