Handle block metadata attribute and related experimental APIs (#47791)

* Move PHP attribute registration to experiments dir

* Limit __experimentalMetadata to Core blocks

* fix check

---------

Co-authored-by: ntsekouras <ntsekouras@outlook.com>

lib/compat/wordpress-6.1/blocks.php

@@ -323,28 +323,3 @@ function gutenberg_block_type_metadata_render_template( $settings, $metadata ) {
 	return $settings;
 }
 add_filter( 'block_type_metadata_settings', 'gutenberg_block_type_metadata_render_template', 10, 2 );
-
-/**
- * Registers the metadata block attribute for block types.
- *
- * Once 6.1 is the minimum supported WordPress version for the Gutenberg
- * plugin, this shim can be removed
- *
- * @param array $args Array of arguments for registering a block type.
- * @return array $args
- */
-function gutenberg_register_metadata_attribute( $args ) {
-	// Setup attributes if needed.
-	if ( ! isset( $args['attributes'] ) || ! is_array( $args['attributes'] ) ) {
-		$args['attributes'] = array();
-	}
-
-	if ( ! array_key_exists( 'metadata', $args['attributes'] ) ) {
-		$args['attributes']['metadata'] = array(
-			'type' => 'object',
-		);
-	}
-
-	return $args;
-}
-add_filter( 'register_block_type_args', 'gutenberg_register_metadata_attribute' );

lib/experimental/blocks.php

@@ -77,3 +77,26 @@ function wp_enqueue_block_view_script( $block_name, $args ) {
 		add_filter( 'render_block', $callback, 10, 2 );
 	}
 }
+
+
+/**
+ * Registers the metadata block attribute for block types.
+ *
+ * @param array $args Array of arguments for registering a block type.
+ * @return array $args
+ */
+function gutenberg_register_metadata_attribute( $args ) {
+	// Setup attributes if needed.
+	if ( ! isset( $args['attributes'] ) || ! is_array( $args['attributes'] ) ) {
+		$args['attributes'] = array();
+	}
+
+	if ( ! array_key_exists( 'metadata', $args['attributes'] ) ) {
+		$args['attributes']['metadata'] = array(
+			'type' => 'object',
+		);
+	}
+
+	return $args;
+}
+add_filter( 'register_block_type_args', 'gutenberg_register_metadata_attribute' );

packages/block-editor/src/hooks/metadata.js

@@ -7,6 +7,10 @@ import { getBlockSupport } from '@wordpress/blocks';
 const META_ATTRIBUTE_NAME = 'metadata';
 
 export function hasBlockMetadataSupport( blockType, feature = '' ) {
+	// Only core blocks are allowed to use __experimentalMetadata until the fetaure is stablised.
+	if ( ! blockType.name.startsWith( 'core/' ) ) {
+		return false;
+	}
 	const support = getBlockSupport( blockType, '__experimentalMetadata' );
 	return !! ( true === support || support?.[ feature ] );
 }