Editor: add Post Content attributes to block editor settings.

Adds a new block editor setting containing the Post Content block attributes, if they exist.

Props audrasjb, spacedmonkey, jeremyfelt, mukesh27, flixos90, andrewserong.
Fixes #58534.


git-svn-id: https://develop.svn.wordpress.org/trunk@55955 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/block-editor.php

@@ -361,6 +361,92 @@ function _wp_get_iframed_editor_assets() {
 	);
 }
 
+/**
+ * Finds the first occurrence of a specific block in an array of blocks.
+ *
+ * @since 6.3.0
+ *
+ * @param array  $blocks     Array of blocks.
+ * @param string $block_name Name of the block to find.
+ * @return array Found block, or empty array if none found.
+ */
+function wp_get_first_block( $blocks, $block_name ) {
+	foreach ( $blocks as $block ) {
+		if ( $block_name === $block['blockName'] ) {
+			return $block;
+		}
+		if ( ! empty( $block['innerBlocks'] ) ) {
+			$found_block = wp_get_first_block( $block['innerBlocks'], $block_name );
+
+			if ( ! empty( $found_block ) ) {
+				return $found_block;
+			}
+		}
+	}
+
+	return array();
+}
+
+/**
+ * Retrieves Post Content block attributes from the current post template.
+ *
+ * @since 6.3.0
+ * @access private
+ *
+ * @global int $post_ID
+ *
+ * @return array Post Content block attributes or empty array if they don't exist.
+ */
+function wp_get_post_content_block_attributes() {
+	global $post_ID;
+
+	$is_block_theme = wp_is_block_theme();
+
+	if ( ! $is_block_theme || ! $post_ID ) {
+		return array();
+	}
+
+	$template_slug = get_page_template_slug( $post_ID );
+
+	if ( ! $template_slug ) {
+		$post_slug      = 'singular';
+		$page_slug      = 'singular';
+		$template_types = get_block_templates();
+
+		foreach ( $template_types as $template_type ) {
+			if ( 'page' === $template_type->slug ) {
+				$page_slug = 'page';
+			}
+			if ( 'single' === $template_type->slug ) {
+				$post_slug = 'single';
+			}
+		}
+
+		$what_post_type = get_post_type( $post_ID );
+		switch ( $what_post_type ) {
+			case 'page':
+				$template_slug = $page_slug;
+				break;
+			default:
+				$template_slug = $post_slug;
+				break;
+		}
+	}
+
+	$current_template = get_block_templates( array( 'slug__in' => array( $template_slug ) ) );
+
+	if ( ! empty( $current_template ) ) {
+		$template_blocks    = parse_blocks( $current_template[0]->content );
+		$post_content_block = wp_get_first_block( $template_blocks, 'core/post-content' );
+
+		if ( ! empty( $post_content_block['attrs'] ) ) {
+			return $post_content_block['attrs'];
+		}
+	}
+
+	return array();
+}
+
 /**
  * Returns the contextualized block editor settings for a selected editor context.
  *
@@ -529,6 +615,12 @@ function get_block_editor_settings( array $custom_settings, $block_editor_contex
 		),
 	);
 
+	$post_content_block_attributes = wp_get_post_content_block_attributes();
+
+	if ( ! empty( $post_content_block_attributes ) ) {
+		$editor_settings['postContentAttributes'] = $post_content_block_attributes;
+	}
+
 	/**
 	 * Filters the settings to pass to the block editor for all editor type.
 	 *