Block Hooks: Enable for post content.

Block Hooks were previously only applied to layout elements such as templates, template parts, patterns, and navigation menus -- things that are edited in the Site Editor.

This changeset enables Block Hooks in post content. The parity between frontend and editor is preserved: Blocks inserted by Block Hooks are visible both on the frontend and in the editor, and any customizations made by the user are respected on the frontend.

This is possible thanks to setting the `metadata.ignoredHookedBlocks` attribute on anchor blocks (a technique first introduced in [57594]). For first child and last child insertion into a Post Content block, the corresponding post object's `_wp_ignored_hooked_blocks` post meta is set.

Props bernhard-reiter, gziolo, jonsurrell, karolmanijak, leewillis77.
Fixes #61074.

git-svn-id: https://develop.svn.wordpress.org/trunk@59523 602fd350-edb4-49c9-b593-d223f7449a82

Author: ockham

src/wp-includes/blocks.php

@@ -912,7 +912,7 @@ function insert_hooked_blocks( &$parsed_anchor_block, $relative_position, $hooke
 	 * @param string                          $relative_position  The relative position of the hooked blocks.
 	 *                                                            Can be one of 'before', 'after', 'first_child', or 'last_child'.
 	 * @param string                          $anchor_block_type  The anchor block type.
-	 * @param WP_Block_Template|WP_Post|array $context            The block template, template part, `wp_navigation` post type,
+	 * @param WP_Block_Template|WP_Post|array $context            The block template, template part, post object,
 	 *                                                            or pattern that the anchor block belongs to.
 	 */
 	$hooked_block_types = apply_filters( 'hooked_block_types', $hooked_block_types, $relative_position, $anchor_block_type, $context );
@@ -935,7 +935,7 @@ function insert_hooked_blocks( &$parsed_anchor_block, $relative_position, $hooke
 		 * @param string                          $hooked_block_type   The hooked block type name.
 		 * @param string                          $relative_position   The relative position of the hooked block.
 		 * @param array                           $parsed_anchor_block The anchor block, in parsed block array format.
-		 * @param WP_Block_Template|WP_Post|array $context             The block template, template part, `wp_navigation` post type,
+		 * @param WP_Block_Template|WP_Post|array $context             The block template, template part, post object,
 		 *                                                             or pattern that the anchor block belongs to.
 		 */
 		$parsed_hooked_block = apply_filters( 'hooked_block', $parsed_hooked_block, $hooked_block_type, $relative_position, $parsed_anchor_block, $context );
@@ -951,7 +951,7 @@ function insert_hooked_blocks( &$parsed_anchor_block, $relative_position, $hooke
 		 * @param string                          $hooked_block_type   The hooked block type name.
 		 * @param string                          $relative_position   The relative position of the hooked block.
 		 * @param array                           $parsed_anchor_block The anchor block, in parsed block array format.
-		 * @param WP_Block_Template|WP_Post|array $context             The block template, template part, `wp_navigation` post type,
+		 * @param WP_Block_Template|WP_Post|array $context             The block template, template part, post object,
 		 *                                                             or pattern that the anchor block belongs to.
 		 */
 		$parsed_hooked_block = apply_filters( "hooked_block_{$hooked_block_type}", $parsed_hooked_block, $hooked_block_type, $relative_position, $parsed_anchor_block, $context );
@@ -1039,17 +1039,25 @@ function set_ignored_hooked_blocks_metadata( &$parsed_anchor_block, $relative_po
  *
  * @since 6.6.0
  * @since 6.7.0 Injects the `theme` attribute into Template Part blocks, even if no hooked blocks are registered.
+ * @since 6.8.0 Have the `$context` parameter default to `null`, in which case `get_post()` will be called to use the current post as context.
  * @access private
  *
- * @param string                          $content  Serialized content.
- * @param WP_Block_Template|WP_Post|array $context  A block template, template part, `wp_navigation` post object,
- *                                                  or pattern that the blocks belong to.
- * @param callable                        $callback A function that will be called for each block to generate
- *                                                  the markup for a given list of blocks that are hooked to it.
- *                                                  Default: 'insert_hooked_blocks'.
+ * @param string                               $content  Serialized content.
+ * @param WP_Block_Template|WP_Post|array|null $context  A block template, template part, post object, or pattern
+ *                                                       that the blocks belong to. If set to `null`, `get_post()`
+ *                                                       will be called to use the current post as context.
+ *                                                       Default: `null`.
+ * @param callable                             $callback A function that will be called for each block to generate
+ *                                                       the markup for a given list of blocks that are hooked to it.
+ *                                                       Default: 'insert_hooked_blocks'.
  * @return string The serialized markup.
  */
-function apply_block_hooks_to_content( $content, $context, $callback = 'insert_hooked_blocks' ) {
+function apply_block_hooks_to_content( $content, $context = null, $callback = 'insert_hooked_blocks' ) {
+	// Default to the current post if no context is provided.
+	if ( null === $context ) {
+		$context = get_post();
+	}
+
 	$hooked_blocks = get_hooked_blocks();
 
 	$before_block_visitor = '_inject_theme_attribute_in_template_part_block';
@@ -1165,36 +1173,37 @@ function extract_serialized_parent_block( $serialized_block ) {
 }
 
 /**
- * Updates the wp_postmeta with the list of ignored hooked blocks where the inner blocks are stored as post content.
- * Currently only supports `wp_navigation` post types.
+ * Updates the wp_postmeta with the list of ignored hooked blocks
+ * where the inner blocks are stored as post content.
  *
  * @since 6.6.0
+ * @since 6.8.0 Support non-`wp_navigation` post types.
  * @access private
  *
  * @param stdClass $post Post object.
  * @return stdClass The updated post object.
  */
 function update_ignored_hooked_blocks_postmeta( $post ) {
 	/*
-	 * In this scenario the user has likely tried to create a navigation via the REST API.
+	 * In this scenario the user has likely tried to create a new post object via the REST API.
 	 * In which case we won't have a post ID to work with and store meta against.
 	 */
 	if ( empty( $post->ID ) ) {
 		return $post;
 	}
 
 	/*
-	 * Skip meta generation when consumers intentionally update specific Navigation fields
+	 * Skip meta generation when consumers intentionally update specific fields
 	 * and omit the content update.
 	 */
 	if ( ! isset( $post->post_content ) ) {
 		return $post;
 	}
 
 	/*
-	 * Skip meta generation when the post content is not a navigation block.
+	 * Skip meta generation if post type is not set.
 	 */
-	if ( ! isset( $post->post_type ) || 'wp_navigation' !== $post->post_type ) {
+	if ( ! isset( $post->post_type ) ) {
 		return $post;
 	}
 
@@ -1208,8 +1217,14 @@ function update_ignored_hooked_blocks_postmeta( $post ) {
 		);
 	}
 
+	if ( 'wp_navigation' === $post->post_type ) {
+		$wrapper_block_type = 'core/navigation';
+	} else {
+		$wrapper_block_type = 'core/post-content';
+	}
+
 	$markup = get_comment_delimited_block_content(
-		'core/navigation',
+		$wrapper_block_type,
 		$attributes,
 		$post->post_content
 	);
@@ -1266,16 +1281,17 @@ function insert_hooked_blocks_and_set_ignored_hooked_blocks_metadata( &$parsed_a
 }
 
 /**
- * Hooks into the REST API response for the core/navigation block and adds the first and last inner blocks.
+ * Hooks into the REST API response for the Posts endpoint and adds the first and last inner blocks.
  *
  * @since 6.6.0
+ * @since 6.8.0 Support non-`wp_navigation` post types.
  *
  * @param WP_REST_Response $response The response object.
  * @param WP_Post          $post     Post object.
  * @return WP_REST_Response The response object.
  */
 function insert_hooked_blocks_into_rest_response( $response, $post ) {
-	if ( ! isset( $response->data['content']['raw'] ) || ! isset( $response->data['content']['rendered'] ) ) {
+	if ( empty( $response->data['content']['raw'] ) || empty( $response->data['content']['rendered'] ) ) {
 		return $response;
 	}
 
@@ -1287,22 +1303,44 @@ function insert_hooked_blocks_into_rest_response( $response, $post ) {
 			'ignoredHookedBlocks' => $ignored_hooked_blocks,
 		);
 	}
+
+	if ( 'wp_navigation' === $post->post_type ) {
+		$wrapper_block_type = 'core/navigation';
+	} else {
+		$wrapper_block_type = 'core/post-content';
+	}
+
 	$content = get_comment_delimited_block_content(
-		'core/navigation',
+		$wrapper_block_type,
 		$attributes,
 		$response->data['content']['raw']
 	);
 
-	$content = apply_block_hooks_to_content( $content, $post );
+	$content = apply_block_hooks_to_content(
+		$content,
+		$post,
+		'insert_hooked_blocks_and_set_ignored_hooked_blocks_metadata'
+	);
 
-	// Remove mock Navigation block wrapper.
+	// Remove mock block wrapper.
 	$content = remove_serialized_parent_block( $content );
 
 	$response->data['content']['raw'] = $content;
 
+	// `apply_block_hooks_to_content` is called above. Ensure it is not called again as a filter.
+	$priority = has_filter( 'the_content', 'apply_block_hooks_to_content' );
+	if ( false !== $priority ) {
+		remove_filter( 'the_content', 'apply_block_hooks_to_content', $priority );
+	}
+
 	/** This filter is documented in wp-includes/post-template.php */
 	$response->data['content']['rendered'] = apply_filters( 'the_content', $content );
 
+	// Restore the filter if it was set initially.
+	if ( false !== $priority ) {
+		add_filter( 'the_content', 'apply_block_hooks_to_content', $priority );
+	}
+
 	return $response;
 }
 
@@ -1320,7 +1358,7 @@ function insert_hooked_blocks_into_rest_response( $response, $post ) {
  * @access private
  *
  * @param array                           $hooked_blocks An array of blocks hooked to another given block.
- * @param WP_Block_Template|WP_Post|array $context       A block template, template part, `wp_navigation` post object,
+ * @param WP_Block_Template|WP_Post|array $context       A block template, template part, post object,
  *                                                       or pattern that the blocks belong to.
  * @param callable                        $callback      A function that will be called for each block to generate
  *                                                       the markup for a given list of blocks that are hooked to it.
@@ -1377,7 +1415,7 @@ function make_before_block_visitor( $hooked_blocks, $context, $callback = 'inser
  * @access private
  *
  * @param array                           $hooked_blocks An array of blocks hooked to another block.
- * @param WP_Block_Template|WP_Post|array $context       A block template, template part, `wp_navigation` post object,
+ * @param WP_Block_Template|WP_Post|array $context       A block template, template part, post object,
  *                                                       or pattern that the blocks belong to.
  * @param callable                        $callback      A function that will be called for each block to generate
  *                                                       the markup for a given list of blocks that are hooked to it.

src/wp-includes/default-filters.php

@@ -192,6 +192,7 @@
 add_filter( 'the_title', 'convert_chars' );
 add_filter( 'the_title', 'trim' );
 
+add_filter( 'the_content', 'apply_block_hooks_to_content', 8 ); // BEFORE do_blocks().
 add_filter( 'the_content', 'do_blocks', 9 );
 add_filter( 'the_content', 'wptexturize' );
 add_filter( 'the_content', 'convert_smilies', 20 );
@@ -760,9 +761,13 @@
 add_filter( 'rest_pre_insert_wp_template_part', 'inject_ignored_hooked_blocks_metadata_attributes' );
 
 // Update ignoredHookedBlocks postmeta for wp_navigation post type.
+add_filter( 'rest_pre_insert_page', 'update_ignored_hooked_blocks_postmeta' );
+add_filter( 'rest_pre_insert_post', 'update_ignored_hooked_blocks_postmeta' );
 add_filter( 'rest_pre_insert_wp_navigation', 'update_ignored_hooked_blocks_postmeta' );
 
-// Inject hooked blocks into the wp_navigation post type REST response.
+// Inject hooked blocks into the Posts endpoint REST response for some given post types.
+add_filter( 'rest_prepare_page', 'insert_hooked_blocks_into_rest_response', 10, 2 );
+add_filter( 'rest_prepare_post', 'insert_hooked_blocks_into_rest_response', 10, 2 );
 add_filter( 'rest_prepare_wp_navigation', 'insert_hooked_blocks_into_rest_response', 10, 2 );
 
 unset( $filter, $action );

tests/phpunit/tests/blocks/applyBlockHooksToContent.php

@@ -91,6 +91,26 @@ public function test_apply_block_hooks_to_content_inserts_hooked_block() {
 		);
 	}
 
+	/**
+	 * @ticket 61074
+	 */
+	public function test_apply_block_hooks_to_content_with_context_set_to_null() {
+		$content = '<!-- wp:tests/anchor-block /-->';
+
+		/*
+		 * apply_block_hooks_to_content() will fall back to the global $post object (via get_post())
+		 * if the $context parameter is null. However, we'd also like to ensure that the function
+		 * works as expected even when get_post() returns null.
+		 */
+		$this->assertNull( get_post() );
+
+		$actual = apply_block_hooks_to_content( $content, null, 'insert_hooked_blocks' );
+		$this->assertSame(
+			'<!-- wp:tests/anchor-block /--><!-- wp:tests/hooked-block /-->',
+			$actual
+		);
+	}
+
 	/**
 	 * @ticket 61902
 	 */