Problem/Motivation
Deleting a node in the middle/top of the menu tree causes unexpected results for content editors.
Steps to reproduce
1. Install Drupal Core
2. Create some nodes and build out a simple main menu tree like
Children's Health, Safety and Wellbeing
Mental Health
|- ADHD
|- Anxiety and depression
|- Autism
3. Delete the "Mental Health" node
Woah, all of a sudden the main navigation (site-wide) has all these new top-level menu items. This is even more of a surprise if the "Mental Health" menu item was disabled, or its node was unpublished (because you would've forgotten that it has children).
Proposed resolution
Warn before the delete (but we can't do that everywhere), and notify after the delete.
Warn before
/node/*/delete currently says
Are you sure you want to delete the content item ?
This action cannot be undone.
We should also say something like
This page has 3 menu children. These will be moved one page higher in the menu hierarchy
* Foo (link to /admin/structure/menu/item/[id]/edit)
* Bar (link to /admin/structure/menu/item/[id]/edit)
* Baz (link to /admin/structure/menu/item/[id]/edit)
Notify after
Not all node deletions go through /node/*/delete. So we should also show a warning message afterwards (same as above, just changing the verb tense):
A page was deleted that had 3 menu children. These have been moved one page higher in the menu hierarchy
* Foo (link to /admin/structure/menu/item/[id]/edit)
* Bar (link to /admin/structure/menu/item/[id]/edit)
* Baz (link to /admin/structure/menu/item/[id]/edit)
Remaining tasks
* Discussion
* Implementation
User interface changes
* New messaging
API changes
None
Data model changes
None
Release notes snippet
TBD