Parts assigned to their own area do not appear in the site editor library.

[inc2734]

Description

Areas added with filter hooks do not appear in the site editor library. Template parts assigned to that area do not appear in the list even if they are created.

Code to add an area

function my_default_wp_template_part_areas( $default_area_definitions ) {
	return array_merge(
		$default_area_definitions,
		array(
			array(
				'area'        => 'my-area',
				'label'       => 'My Area',
				'icon'        => 'layout',
				'description' => '',
			),
		)
	);
}
add_filter( 'default_wp_template_part_areas', 'my_default_wp_template_part_areas' );

Step-by-step reproduction instructions

• Add new area with the default_wp_template_part_areas filter hook.
• Create a template part assigned to that area.
• When we go to the library, we will see a list of template part areas, but not the unique area we added.
• The number of template parts assigned to uncategorize is increasing, but they are not shown in the preview.
• The same problem occurs whether template parts are created in the site editor or added to the parts directory.

Screenshots, screen recording, code snippet

Kapture.2023-06-29.at.14.30.20.mp4

Environment info

• WordPress 6.3 beta2
• Twenty Twenty-ThreeVersion: 1.1
• Gutenberg 16.1.0 Enable/Disable

Please confirm that you have searched existing issues in the repo.

Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

Yes

[bd-viget]

I may need to open a new issue for this, however after this has been added, I'm wondering why can't the template part just display under its own custom section, rather than having them all in General?

If I use the default_wp_template_part_areas filter to defined my own custom area, this should reflect in the FSE UI next to General, Header, and Footer.

And a side question, are our only options for icons layout, header, and footer? Is there no support for custom icons or passing an SVG value?

[bd-viget]

Another issue here is the value passed for area_tag is not honored. Using the following as an example:

function my_default_wp_template_part_areas( $default_area_definitions ) {
	return array_merge(
		$default_area_definitions,
		array(
			array(
				'area'        => 'my-area',
				'label'       => 'My Area',
				'icon'        => 'layout',
				'description' => '',
				'area_tag'    => 'nav',
			),
		)
	);
}
add_filter( 'default_wp_template_part_areas', 'my_default_wp_template_part_areas' );

In my use case, I'm using render_block_core_template_part and the tag used in the output is <div>