Description

While testing the template activation feature with a plugin-registered template in Gutenberg 21.8.2, I found a few issues.

The bugs might be in the Template registration API itself, or I might have done something wrong in my testing. In any case, documenting them here in case they are useful:

Step-by-step reproduction instructions

1. Add this code to an existing plugin or in a code snippet using the Code Snippets plugin:

add_action(
	'init',
	function () {
		register_block_template(
			'gutenberg//plugin-template',
			array(
				'title'       => 'Plugin Template',
				'description' => 'A template registered by a plugin.',
				'content'     => '<!-- wp:template-part {"slug":"header","tagName":"header"} /--><!-- wp:group {"tagName":"main","layout":{"inherit":true}} --><main class="wp-block-group"><!-- wp:paragraph --><p>This is a plugin-registered template.</p><!-- /wp:paragraph --></main><!-- /wp:group -->',
			)
		);
		add_action(
			'category_template_hierarchy',
			function () {
				return array( 'plugin-template' );
			}
		);
	}
);

You can optionally also add the snippet below, but I don't think it makes a difference:

		add_filter(
			'default_template_types',
			function ( $default_template_types ) {
				$default_template_types['gutenberg//plugin-template'] = array(
					'title'       => 'Plugin Template',
					'description' => 'A template registered by a plugin.',
				);
				return $default_template_types;
			}
		);

2. Go to /category/my-category/ to verify the template is applied correctly:

3. Click on Edit Site in the top bar.
4. Now, click on the Actions menu:

• Issue 1: It allows moving the template to trash, but this doesn't seem to make any difference in the frontend: the template keeps being rendered. I believe the editor shouldn't allow moving plugin-registered templates to trash.

5. Go back to /category/my-category/ and click on Edit Site. Make some edits to the template, save and activate the template. Verify they are applied in the frontend.

6. Click on Edit Site again.

• Issue 2: This brings you to the unmodified template, instead of the template you just edited.

7. Go to Appearance > Editor > Templates > Active templates. Open the modified Plugin Template, deactivate it and then move it to the trash.
8. Now go to Appearance > Editor > Templates > Gutenberg.
9. Activate the plugin template:

• Issue 3: Activating a plugin template doesn't seem to do anything. If after activating it you go to Active templates, it's not there.

Screenshots, screen recording, code snippet

No response

Environment info

• WordPress 6.9-alpha-60939.
• Gutenberg trunk.

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

Please confirm which theme type you used for testing.

• Block
• Classic
• Hybrid (e.g. classic with theme.json)
• Not sure