Action on Pop
iOS 13+, Xcode 11.4.1, Storyboard-based application.
I am using a navigation stack to manage some data edits. That is,
• nav-controller root is a list of items.
• tap on item to segue to a detail panel to edit an item (which is a collection of subItems)
• subItems may either be edited on the detail panel or
• tap on a subItem to segue to a subDetail panel
(Typically, this stack is three layers deep, but I'm looking for a solution that works for arbitrary depth.)
Now for all levels of this hierarchy, if the user taps the back button (or performs a gesture with same effect), I need to recognize this fact so that I can pass data up the hierarchy (hopefully without requiring strong coupling throughout).
The way I'm currently doing this is to execute a closure in each panel's deinit method. (Note that viewWillDisappear does not work except in the case of stack-depth == 2)). However putting this kind of code in deinit seems to me to be a code-smell.
Can you suggest an alternate that works at all levels of an arbitrarily deep navigation stack?