Undo doesn't work with Table of Contents block

[maximebj]

Undo doesn't work with Table of Contents block

[maximebj]

I can reproduce the issue, and it's very annoying.
Also I use a light version of the Gutenberg code to get the headings (the process that initially list all headings in the top of the editor).
For now it cannot list heading in groups and columns. So I need to improve this a lot.

It would be awesome if such a block finishes in the core.

[maximebj]

Tell me if a solution shows up because it's beyond my coding level!

[ZebulanStanphill]

@maximebj My table of contents block PR for the Gutenberg project is now in as good a state as it can get without additional APIs being introduced. It doesn't have the undo problem, and really, the only problem it does have is an edge-case issue with <!--nextpage--> tags not being counted correctly in the editor (the front end is fine), which I don't think your implementation even attempts to handle in the first place.

Because of the aforementioned edge-cases, I've avoided merging the block into core, but I think the implementation is fine for a plugin, so feel free to copy anything from my implementation to improve or fix your own.