aria-label="(?[^"]+)?")@i'; $content = preg_replace_callback( $pattern, function ( $matches ) { $filename = ! empty( $matches['filename'] ) ? $matches['filename'] : ''; $has_filename = ! empty( $filename ) && 'PDF embed' !== $filename; $label = $has_filename ? sprintf( /* translators: %s: filename. */ __( 'Embed of %s.' ), $filename ) : __( 'PDF embed' ); return str_replace( $matches['attribute'], sprintf( 'aria-label="%s"', $label ), $matches[0] ); }, $content ); return $content; } /** * Registers the `core/file` block on server. */ function register_block_core_file() { register_block_type_from_metadata( __DIR__ . '/file', array( 'render_callback' => 'render_block_core_file', ) ); } add_action( 'init', 'register_block_core_file' );