Allow which metatags are visible on the field widget to be editable

I rerolled the patch to 2.0.0.
For now I'm not able to set the branch to 2.0.x and provide a merge request, hope someone else can do it.

This would be a welcome addition to the Metatags module! The forms are too long now and contain obsolete information:

• The Basic tags contain two fields that are no longer supported. This information clutters the interface.
• The Open Graph tags form is really long.

I mostly try to avoid printing the form for website editors (mostly by using a summary field) but sometimes they want a custom metatag description.

I'm currently hiding the unused metatags in Seven with some CSS (I use a small custom module to override the admin styling):

#edit-field-metatags-0-basic .form-item,
#edit-field-metatags-0-open-graph .form-item {
	display: none;
}

#edit-field-metatags-0-basic .form-item.form-item-field-metatags-0-basic-title,
#edit-field-metatags-0-basic .form-item.form-item-field-metatags-0-basic-description,
#edit-field-metatags-0-open-graph .form-item.form-item-field-metatags-0-open-graph-og-title,
#edit-field-metatags-0-open-graph .form-item.form-item-field-metatags-0-open-graph-og-description {
	display: block;
}

This will expose only the meta title and description on the basic and Open Graph fields. It's a dirty solutions but it helps to clean up the interface.

Changing the status as I have successfully applied this patch.

Anyone have any success re-rolling against 2.1?

Re-rolled patch against 2.1.x branch and created MR.

Thanks for the patch. It's working fine with metatag 2.1.0. Just adding my 2 cents that using the small select box is not the best UX.

I tested the merge request and it seemed to work perfectly (Metatag 2.1.0, D10.3.9). Thank you for the great feature!

I agree with balagan that selection of multiple fields with the current widget was not super easy/intuitive. But the ability to select the editable metatags in the first place is a huge improvement. I don't have any better suggestions at the moment.

scott_euser → changed the visibility of the branch metatag-3108108 to hidden.

scott_euser → changed the visibility of the branch 3108108-allow-which-metatags to active.

scott_euser → changed the visibility of the branch 8.x-1.x to hidden.

Hmmm can't seem to get the fork to sync from upstream repo, not sure if its because I'm not the owner of the fork. No possibility to create a new fork from 2.1.x. I could create a new issue, but shame to lose all the history

scott_euser → changed the visibility of the branch 2.1.x to hidden.

scott_euser → changed the visibility of the branch 3108108-allow-which-metatags to hidden.

Okay sorted for 2.1.x. Tests pass again BUT this could use more test coverage for the new functionality.

I also implemented a variation of @jrockowitz suggestion to improve the UX with checkboxes rather than select multiple.

For those updating to this patch, since update hooks are not done between patch versions, the simplest is to:

1. Control + F your config/sync/ directory for 'editable_tags'
2. Nest them within the tag group ID like this diff below:

 settings:
   editable_tags:
-    title: title
-    description: description
+    basic:
+      title: title
+      description: description

Added test coverage as well. Existing phpstan/d12 depreciations should remain out of scope.

Would be great if someone can review so we can get this fairly long standing one in.

Thanks!