Show post meta fields in revisions panel

[SantosGuillamot]

Trac ticket:

I can see that there was a similar closed ticket for this and a related pull request.

I just left a comment in the trac ticket to discuss how to proceed here.

@adamsilverstein @Mamaduka As you discussed this in the past, it would be great to hear your opinion on the best path forward.

What?

Basically, this pull request shows the changes made to the post meta fields that have revisions enabled in the revisions UI.

Why?

For 6.6, it is planned to allow the editing of custom fields when a block is connected to them. With that, I believe it is important to show the relevant changes in the revisions.

How?

It iterates through the wp_post_revision_meta_keys, and it creates a new row in the diff for each of the meta fields that have changed.

I excluded the footnotes because it has its own section right now, but I am not sure if it should be unified in the proposed "Post Meta".

Demo

This is a quick demo of how it works after the changes in this pull request:

Post.meta.revisions.with.key.demo.mp4

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[Mamaduka]

Sorry for the late reply, @SantosGuillamot! This got lost somewhere in my notifications pile 😓

I think @adamsilverstein's previous decision still holds true. Developers registering post meta/block blindings are better positioned to decide what to display on the revisions screen.

Reconsidering whether we should add this automatically - developers would be better suited to know what they want to display on this screen, core should only handle fields we add directly (eg. footnotes).

[gziolo]

Reconsidering whether we should add this automatically - developers would be better suited to know what they want to display on this screen, core should only handle fields we add directly (eg. footnotes).

Slightly related. That also nicely ties into the previous discussion on whether to share the feedback for users in the UI. In case of Footnotes it was treated as an internal change that never should be surfaced to the users, while for other custom post meta there might be sometimes temptation to highlight that to users.