Improve Breadcrumbs block using WordPress SEO logic

[bobbingwide]

In the prototyped version of the block ( #1 ) I implemented a call to yoast_breadcrumb() if it was available.

When the Breadcrumbs setting was Disabled then the function returned null, so the code then defaulted to my own logic.

When the Breadcrumbs setting was Enabled then the breadcrumb was displayed.

But, the results in the editor didn't match the results in the browser.
In the editor I just get "Home"
In the front-end the trail includes archive links for CPTs.

e.g. when viewing
https://s.b/oikcom/block/breadcrumbs-block-sb-breadcrumbs-block/

the trail is:

'Ome » Blocks » Breadcrumbs block – sb/breadcrumbs-block

where:

• 'Ome is the string I've chosen for for Home
• » is the default separator
• and the values to the left of the separators are linked to the substring of the permalink.

Requirement

To get the same output in the editor as in the front-end.

Proposed solution

Don't know yet, but see if there's anything happening in... Yoast/wordpress-seo#14204

[bobbingwide]

Intermediate solution

When the block is being rendered with Server Side Rendering, i.e. when it's a REST_REQUEST, then we won't call the WordPress SEO logic. We just use the default function sb_breadcrumbs_block_dynamic_block_internal()

The block will look slightly different from the front end since it won't be picking up the user defined / default values for "Home" and the separator. Perhaps we should make these block settings.

[bobbingwide]

v0.6.0 now released with server side rendering support for Yoast SEO's breadcrumbs logic.
Note: Yoast SEO provides its own breadcrumbs block.