Elements: Deprecate old block support filter callbacks

lib/block-supports/elements.php

@@ -5,6 +5,19 @@
  * @package gutenberg
  */
 
+/**
+ * Update the block content with elements class names.
+ *
+ * @deprecated 6.6.0 Use `gutenberg_render_elements_class_name` instead.
+ *
+ * @param  string $block_content Rendered block content.
+ * @return string                Filtered block content.
+ */
+function gutenberg_render_elements_support( $block_content ) {
+	_deprecated_function( __FUNCTION__, '6.6.0', 'gutenberg_render_elements_class_name' );
+	return $block_content;
+}
+
 /**
  * Determines whether an elements class name should be added to the block.
  *
@@ -86,11 +99,31 @@ function gutenberg_should_add_elements_class_name( $block, $options ) {
  * This solves the issue of an element (e.g.: link color) being styled in both the parent and a descendant:
  * we want the descendant style to take priority, and this is done by loading it after, in DOM order.
  *
+ * @since 6.6.0 Element block support class and styles are generated via the `render_block_data` filter instead of `pre_render_block`
+ *
  * @param array $parsed_block The parsed block.
  *
  * @return array The same parsed block with elements classname added if appropriate.
  */
 function gutenberg_render_elements_support_styles( $parsed_block ) {
+	/*
+	 * The generation of element styles and classname were moved to the
+	 * `render_block_data` filter in 6.6.0 to avoid filtered attributes
+	 * breaking the application of the elements CSS class.
+	 *
+	 * @see https://github.com/WordPress/gutenberg/pull/59535.
+	 *
+	 * The change in filter means, the argument types for this function
+	 * have changed and require deprecating.
+	 */
+	if ( is_string( $parsed_block ) ) {
+		_deprecated_argument(
+			__FUNCTION__,
+			'6.6.0',
+			__( 'Use as a `pre_render_block` filter is deprecated. Use with `render_block_data` instead.', 'gutenberg' )
+		);
+	}
+
 	$block_type           = WP_Block_Type_Registry::get_instance()->get_registered( $parsed_block['blockName'] );
 	$element_block_styles = $parsed_block['attrs']['style']['elements'] ?? null;
 
@@ -193,8 +226,8 @@ function gutenberg_render_elements_support_styles( $parsed_block ) {
 }
 
 /**
- * Ensure the elements block support class name generated and added to
- * block attributes in the `render_block_data` filter gets applied to the
+ * Ensure the elements block support class name generated, and added to
+ * block attributes, in the `render_block_data` filter gets applied to the
  * block's markup.
  *
  * @see gutenberg_render_elements_support_styles
@@ -215,17 +248,19 @@ function gutenberg_render_elements_class_name( $block_content, $block ) {
 	$tags = new WP_HTML_Tag_Processor( $block_content );
 
 	if ( $tags->next_tag() ) {
-		// Ensure the elements class name set in render_block_data filter is applied in markup.
-		// See `gutenberg_render_elements_support_styles`.
 		$tags->add_class( $matches[0] );
 	}
 
 	return $tags->get_updated_html();
 }
 
-// Remove WordPress core filters to avoid rendering duplicate elements stylesheet & attaching classes twice.
+// Remove deprecated WordPress core filters.
 remove_filter( 'render_block', 'wp_render_elements_support', 10, 2 );
 remove_filter( 'pre_render_block', 'wp_render_elements_support_styles', 10, 2 );
+
+// Remove WordPress core filters to avoid rendering duplicate elements stylesheet & attaching classes twice.
 remove_filter( 'render_block', 'wp_render_elements_class_name', 10, 2 );
+remove_filter( 'render_block_data', 'wp_render_elements_support_styles', 10, 1 );
+
 add_filter( 'render_block', 'gutenberg_render_elements_class_name', 10, 2 );
-add_filter( 'render_block_data', 'gutenberg_render_elements_support_styles', 10, 2 );
+add_filter( 'render_block_data', 'gutenberg_render_elements_support_styles', 10, 1 );

phpunit/block-supports/elements-test.php

@@ -72,10 +72,12 @@ public function test_elements_block_support_class( $color_settings, $elements_st
 			),
 		);
 
-		// To ensure a consistent elements class name it is generated within a
-		// `render_block_data` filter and stored in the `className` attribute.
-		// As a result the block data needs to be passed through the same
-		// function for this test.
+		/*
+		 * To ensure a consistent elements class name it is generated within a
+		 * `render_block_data` filter and stored in the `className` attribute.
+		 * As a result the block data needs to be passed through the same
+		 * function for this test.
+		 */
 		$filtered_block = gutenberg_render_elements_support_styles( $block );
 		$actual         = gutenberg_render_elements_class_name( $block_markup, $filtered_block );