Tiptap RTE: Undo deleted blocks

[leekelleher]

Description

Fixes #19637.

Enables RTE Blocks to be "un-deleted", with the RTE's undo action.

In the RTE property-editor base class, a state of unused (deleted) blocks is maintained, so that if an RTE's undo action restores a block in the markup, the unused block data can be re-added.

How to test?

In a Tiptap RTE, try adding a block element (with data, content and/or settings), now delete the block to remove it from the RTE, then perform an undo action (either by the undo toolbar button or keyboard shortcut CTRL+Z). The block should be restored and content/settings property data is still present.

[Copilot]

Pull Request Overview

This PR implements undo functionality for deleted blocks in the Tiptap RTE by maintaining a cache of unused block data that can be restored when the RTE's undo action brings back previously deleted blocks.

• Adds lookup maps to cache deleted block layout, content, and settings data
• Implements restoration logic to re-add cached block data when content keys are referenced again
• Adds proper cleanup in the destroy method to prevent memory leaks

[nikolaj-kaplan]

Will this fix also solve a similar problem that occurs when you try to cut and paste a block?
Currently when I select a block and use ctrl-x the block disappears as expected, but I am unable to paste it elsewhere in the RTE.

[leekelleher]

Will this fix also solve a similar problem that occurs when you try to cut and paste a block? Currently when I select a block and use ctrl-x the block disappears as expected, but I am unable to paste it elsewhere in the RTE.

@nikolaj-kaplan Yes, this patch will support cut-and-paste of block elements. 👍

[AndyButland]

Just testing this out - looks to work but there's a couple of glitches I found.

1. With an entered block looking like this:

Once I remove it and undo to restore it, it comes back like this (note greyed out, and with a + icon instead of an edit one - though clicking the + does allow to edit):

2. You can copy/paste a block within an editor, which works fine. But then if you edit the copied block, it'll update the settings on the original one too.

[leekelleher]

1. With an entered block looking like this:
   ...
   Once I remove it and undo to restore it, it comes back like this (note greyed out, and with a + icon instead of an edit one - though clicking the + does allow to edit):

@AndyButland, This seems to happen on variant pages. I'll look into a fix.

2. You can copy/paste a block within an editor, which works fine. But then if you edit the copied block, it'll update the settings on the original one too.

I suspect the same happens outside of this PR. Definitely something for us to look into further. 🕵️

[leekelleher]

@AndyButland I've patched up the issue on variant documents, ready to re-review.

[AndyButland]

Working as expected now for point 1, as I understand for point 2 it's not caused in this PR so will be tackled separately.