Create a Preferred Editor meta box

[bobbingwide]

As part of the effort to determine Gutenberg’s compatibility with an existing site’s content we need to drill down into each individual post to evaluate which editor would be the recommended editor for the current content. From these figures we can attempt to determine the overall compatibility of the Block editor with the site’s content.

Each post can be evaluated for compatibility with the Block editor and can be assigned a preferred editor state.

Preferred editor	Label	Compatible?	Notes
A	Any / Ambivalent	Yes	Not deemed incompatible
B	Block	Yes	Already converted to blocks
C	Classic	No	Deemed incompatible
?	Unknown	Yes	Assumed compatible until analysed

Any post which has not yet been analysed may be considered to be in an Unknown state - equivalent to A.

Each ‘editable’ post type can also be classified as A, B or C For the [content] shortcode 5 different post type classifications were produced. There should have been 6. This table maps the classifications.

Classification	Content	Notes
A	Gutenberg	Block editor capable
B	Block	Must be edited using the block editor
C	Classic	Must be edited using the classic editor
?	Media
?	Revision
?	n/a

Note: Post types classified as B do not yet exist.

Proposed solution

• Each editable post will be assigned a preferred editor meta field, key _oik_block_editor.
• This will be based upon ‘opinions’.
• For B or C this value may be mandatory
• The meta box will explain the opinions.
• Any user may choose to force a mandatory opinion of B or C.
• The stored value may be used to control which editor the user can use.

[bobbingwide]

I did think of an example where Preferred editor ‘A’ could actually be Mandatory. I can’t remember why exactly. Possibly something to do with the user wanting to be able to use either editor even though the opinions suggest that ‘B’ or ‘C’ is mandatory. The routine that evaluates opinions should take this into account.

[bobbingwide]

It's now mid June 2021. I don't need this meta box anymore. Certainly not in the block editor. Perhaps the routine should only display the block in the Classic editor. The simplest solution might be to make it appear that the meta box is not compatible with the block editor. by setting __block_editor_compatible_meta_box to false. or __back_compat_meta_box to true.

See https://developer.wordpress.org/block-editor/how-to-guides/backward-compatibility/meta-box/

Even though I've not created a block to display this information, the second option seems preferable.