Block Hooks: Use new Templates Controller filter instead of action.

This changeset adds a new `rest_pre_insert_{$this->post_type}` filter in the `WP_REST_Templates_Controller`, where it is applied to the return value of the `prepare_item_for_database` method. (This is consistent with the `WP_REST_Post_Controller`, where that filter has existed before.)

The new filter is then used to inject hooked blocks into the template (or template part) content received via the endpoint, prior to persisting it to the database.

This supersedes the previous mechanism, which was using the `rest_after_insert_{$this->post_type}` ''action'', from which it performed an additional `wp_update_post` call to update the template (part) content with the hooked blocks injected. The new technique eschews that additional call and the resulting extra revision it created, as well as a problem with regard to duplicated escaping and sanitization, which had caused some special characters to be garbled.

Props tomjcafferkey, gziolo, swissspidy, karolmanijak.
Fixes #60671.
Built from https://develop.svn.wordpress.org/trunk@57790


git-svn-id: http://core.svn.wordpress.org/trunk@57291 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/block-template-utils.php

@@ -1432,39 +1432,48 @@ function get_template_hierarchy( $slug, $is_custom = false, $template_prefix = '
 	$template_hierarchy[] = 'index';
 	return $template_hierarchy;
 }
+
 /**
  * Inject ignoredHookedBlocks metadata attributes into a template or template part.
  *
- * Given a `wp_template` or `wp_template_part` post object, locate all blocks that have
+ * Given an object that represents a `wp_template` or `wp_template_part` post object
+ * prepared for inserting or updating the database, locate all blocks that have
  * hooked blocks, and inject a `metadata.ignoredHookedBlocks` attribute into the anchor
  * blocks to reflect the latter.
  *
- * @param WP_Post $post A post object with post type set to `wp_template` or `wp_template_part`.
- * @return WP_Post The updated post object.
+ * @since 6.5.0
+ * @access private
+ *
+ * @param stdClass        $post    An object representing a template or template part
+ *                                 prepared for inserting or updating the database.
+ * @param WP_REST_Request $request Request object.
+ * @return stdClass The updated object representing a template or template part.
  */
-function inject_ignored_hooked_blocks_metadata_attributes( $post ) {
+function inject_ignored_hooked_blocks_metadata_attributes( $post, $request ) {
+	$filter_name = current_filter();
+	if ( ! str_starts_with( $filter_name, 'rest_pre_insert_' ) ) {
+		return $post;
+	}
+	$post_type = str_replace( 'rest_pre_insert_', '', $filter_name );
+
 	$hooked_blocks = get_hooked_blocks();
 	if ( empty( $hooked_blocks ) && ! has_filter( 'hooked_block_types' ) ) {
-		return;
+		return $post;
 	}
 
 	// At this point, the post has already been created.
 	// We need to build the corresponding `WP_Block_Template` object as context argument for the visitor.
 	// To that end, we need to suppress hooked blocks from getting inserted into the template.
 	add_filter( 'hooked_block_types', '__return_empty_array', 99999, 0 );
-	$template = _build_block_template_result_from_post( $post );
+	$template = $request['id'] ? get_block_template( $request['id'], $post_type ) : null;
 	remove_filter( 'hooked_block_types', '__return_empty_array', 99999 );
 
 	$before_block_visitor = make_before_block_visitor( $hooked_blocks, $template, 'set_ignored_hooked_blocks_metadata' );
 	$after_block_visitor  = make_after_block_visitor( $hooked_blocks, $template, 'set_ignored_hooked_blocks_metadata' );
 
-	$blocks  = parse_blocks( $template->content );
+	$blocks  = parse_blocks( $post->post_content );
 	$content = traverse_and_serialize_blocks( $blocks, $before_block_visitor, $after_block_visitor );
 
-	wp_update_post(
-		array(
-			'ID'           => $post->ID,
-			'post_content' => $content,
-		)
-	);
+	$post->post_content = $content;
+	return $post;
 }

wp-includes/default-filters.php

@@ -752,9 +752,8 @@ add_action( 'deleted_post', '_wp_after_delete_font_family', 10, 2 );
 add_action( 'before_delete_post', '_wp_before_delete_font_face', 10, 2 );
 add_action( 'init', '_wp_register_default_font_collections' );
 
-// It might be nice to use a filter instead of an action, but the `WP_REST_Templates_Controller` doesn't
-// provide one (unlike e.g. `WP_REST_Posts_Controller`, which has `rest_pre_insert_{$this->post_type}`).
-add_action( 'rest_after_insert_wp_template', 'inject_ignored_hooked_blocks_metadata_attributes', 10, 3 );
-add_action( 'rest_after_insert_wp_template_part', 'inject_ignored_hooked_blocks_metadata_attributes', 10, 3 );
+// Add ignoredHookedBlocks metadata attribute to the template and template part post types.
+add_filter( 'rest_pre_insert_wp_template', 'inject_ignored_hooked_blocks_metadata_attributes', 10, 2 );
+add_filter( 'rest_pre_insert_wp_template_part', 'inject_ignored_hooked_blocks_metadata_attributes', 10, 2 );
 
 unset( $filter, $action );

wp-includes/rest-api/endpoints/class-wp-rest-templates-controller.php

@@ -619,7 +619,8 @@ class WP_REST_Templates_Controller extends WP_REST_Controller {
 			$changes->post_author = $post_author;
 		}
 
-		return $changes;
+		/** This filter is documented in wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php */
+		return apply_filters( "rest_pre_insert_{$this->post_type}", $changes, $request );
 	}
 
 	/**

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.6-alpha-57789';
+$wp_version = '6.6-alpha-57790';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.