<?php



function block_core_list_render( $attributes, $content ) {
	if ( ! $content ) {
		return $content;
	}

	$processor = new WP_HTML_Tag_Processor( $content );

	$list_tags = array( 'OL', 'UL' );
	while ( $processor->next_tag() ) {
		if ( in_array( $processor->get_tag(), $list_tags, true ) ) {
			$processor->add_class( 'wp-block-list' );
			break;
		}
	}

	return $processor->get_updated_html();
}


function register_block_core_list() {
	register_block_type_from_metadata(
		__DIR__ . '/list',
		array(
			'render_callback' => 'block_core_list_render',
		)
	);
}

add_action( 'init', 'register_block_core_list' );