Hello World * * Would be transformed to: *

Hello World

* * @param array $attributes Attributes of the block being rendered. * @param string $content Content of the block being rendered. * * @return string The content of the block being rendered. */ function block_core_heading_render( $attributes, $content ) { if ( ! $content ) { return $content; } $p = new WP_HTML_Tag_Processor( $content ); $header_tags = array( 'H1', 'H2', 'H3', 'H4', 'H5', 'H6' ); while ( $p->next_tag() ) { if ( in_array( $p->get_tag(), $header_tags, true ) ) { $p->add_class( 'wp-block-heading' ); break; } } return $p->get_updated_html(); } /** * Registers the `core/heading` block on server. */ function register_block_core_heading() { register_block_type_from_metadata( __DIR__ . '/heading', array( 'render_callback' => 'block_core_heading_render', ) ); } add_action( 'init', 'register_block_core_heading' );