Support for WordPress 5.0 and Gutenberg - the new editor

[bobbingwide]

The CPTs registered by oik-shortcodes are not compatible with Gutenberg since they are not REST API enabled. To allow the content to be edited using the block editor we need to add show_in_rest => true to the post type registration.

There are other issues:

1. The _oik_sc_func field is currently a noderef that produces an enormous select list. We should change the field to make it a user entered string / ID See Rebuilding a component invalidates the oik_shortcodes function reference #52

2. Since Gutenberg uses the REST API it expands the content during initial editing. This has been shown to produce problems for the oik_shortcodes CPT. See Support for WordPress 5.0 and the new editor - Gutenberg oik#97 (comment)

[bobbingwide]

With Gutenberg 4.5.1 in herbmiller.me oik-shortcodes appears to prevent dynamic blocks from being processed when the post is being displayed in a single display. The problem does not occur in q.w/hm.

I reconciled the plugin versions and determined that the problem appears to be related to Yoast SEO. When Yoast SEO is deactivated then oik-shortcodes can be reactivated.

The problem has been confirmed to exist with both v8.4 and v9.2.1.
I haven't checked versions earlier than v8.4 nor intermediate versions between v8.4 and v9.2.1.

I tracked the problem down to WordPress/gutenberg#8984 which was developed to fix WordPress/gutenberg#7268.

The workaround would appear to be to delete this line from oik-shortcodes.php

remove_filter( "get_the_excerpt", "wp_trim_excerpt" );

and to change the priority of what was the replacement filter ( from default ( 10 ) to 9 )

add_filter( "get_the_excerpt", "oik_get_the_excerpt", 9);

So it's not really WordPress SEO that's to blame. But if it weren't for WordPress SEO I wouldn't have developed my solution for oik-shortcodes, which subsequently led to the Gutenberg excerpt hack revealing its limitations.

[bobbingwide]

In oik-plugins.co.uk, after having updated oik-a2z and oik-shortcodes-a2z I found I was unable to edit any oik_shortcode post. Investigation indicated it wasn't a problem with these plugins.
It then appeared that the problem was that I was using WordPress 5.0.3 without Gutenberg.
When I activated Gutenberg (4.9) the problem disappeared.
I was unable to reproduce the problem locally.
The problem was a WSOD. The console log showed that jQuery was not loaded.
load-scripts.php load parameter contained jquery-form but not jquery-load.

I didn't get a screen capture of the log, but basically nothing worked.
It only happened for the oik_shortcode post type. Add new worked, edit didn't.

[bobbingwide]

I reproduced the problem on oik-plugins.com

Again, Gutenberg (4.8) was not activated at the time.

[bobbingwide]

I've also reproduced the problem locally, in s.b/oikcom.

[bobbingwide]

The problem is associated with the logic that attempts to generate the programmed example or snippets for a shortcode. This is being executed when the post is being passed through the 'the_content' filter when the post is first opened for editing.
quicktags is unexpectedly enqueued before jquery-core.
The problem is further obfuscated by the fact that the checkboxes may not appear ticked for some instances of the CPT but the logic is being invoked.

Proposed solution

Do not execute the logic when inside the block editor. We might be able to check $current_screen->is_block_editor() at an early stage and avoid doing a lot of unnecessary things. E.g. Disable processing in oiksc_the_content()

The fix also requires changes to be applied in the oik base plugin... where the [bw_code] shortcode already exists in the content. In dependencies_cache::capture_scripts the call to _wp_footer_scripts() causes the problem.

Remember, the problem does not occur when Gutenberg is activated!