Block Hooks API: Add Templates Controller filter to avoid triggering wp_update_post

src/wp-includes/block-template-utils.php

@@ -1432,39 +1432,68 @@ 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
  * 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.
+ * @param stdClass $post A post object with post type set to `wp_template` or `wp_template_part`.
+ * @param WP_REST_Request $request Request object.
+ * @param string   $post_type The post type of the post object.
+ * @return stdClass The updated post object.
  */
-function inject_ignored_hooked_blocks_metadata_attributes( $post ) {
+function inject_ignored_hooked_blocks_metadata_attributes( $post, $request, $post_type ) {
 	$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;
+}
+
+/**
+ * Inject ignoredHookedBlocks metadata attributes into a wp_template_part.
+ *
+ * Given a `wp_template` or `wp_template_part` post object, locate all blocks that have
+ * hooked blocks, and inject a `metadata.ignoredHookedBlocks` attribute into the anchor
+ * blocks to reflect the latter.
+ *
+ * @param stdClass $post A post object with post type set to `wp_template` or `wp_template_part`.
+ * @param WP_REST_Request $request Request object.
+ * @return stdClass The updated post object.
+ */
+function inject_ignored_hooked_blocks_metadata_attributes_into_template_part( $post, $request ) {
+	return inject_ignored_hooked_blocks_metadata_attributes( $post, $request, 'wp_template_part' );
+}
+
+/**
+ * Inject ignoredHookedBlocks metadata attributes into a wp_template.
+ *
+ * Given a `wp_template` or `wp_template_part` post object, locate all blocks that have
+ * hooked blocks, and inject a `metadata.ignoredHookedBlocks` attribute into the anchor
+ * blocks to reflect the latter.
+ *
+ * @param stdClass $post A post object with post type set to `wp_template` or `wp_template_part`.
+ * @param WP_REST_Request $request Request object.
+ * @return stdClass The updated post object.
+ */
+function inject_ignored_hooked_blocks_metadata_attributes_into_template( $post, $request ) {
+	return inject_ignored_hooked_blocks_metadata_attributes( $post, $request, 'wp_template' );
 }

src/wp-includes/default-filters.php

@@ -752,9 +752,8 @@
 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_into_template', 10, 2 );
+add_filter( 'rest_pre_insert_wp_template_part', 'inject_ignored_hooked_blocks_metadata_attributes_into_template_part', 10, 2 );
 
 unset( $filter, $action );

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

@@ -619,7 +619,23 @@ protected function prepare_item_for_database( $request ) {
 			$changes->post_author = $post_author;
 		}
 
-		return $changes;
+		/**
+		 * Filters a post before it is inserted via the REST API.
+		 *
+		 * The dynamic portion of the hook name, `$this->post_type`, refers to the post type slug.
+		 *
+		 * Possible hook names include:
+		 *
+		 *  - `rest_pre_insert_wp_template`
+		 *  - `rest_pre_insert_wp_template_part`
+		 *
+		 * @since 6.5.0
+		 *
+		 * @param stdClass        $changes An object representing a single post prepared
+		 *                                 for inserting or updating the database.
+		 * @param WP_REST_Request $request Request object.
+		 */
+		return apply_filters( "rest_pre_insert_{$this->post_type}", $changes, $request );
 	}
 
 	/**