_oembed_rest_pre_serve_request( bool $served, WP_HTTP_Response $result, WP_REST_Request $request, WP_REST_Server $server ): true

770function _oembed_rest_pre_serve_request( $served, $result, $request, $server ) {771	$params = $request->get_params();772 773	if ( '/oembed/1.0/embed' !== $request->get_route() || 'GET' !== $request->get_method() ) {774		return $served;775	}776 777	if ( ! isset( $params['format'] ) || 'xml' !== $params['format'] ) {778		return $served;779	}780 781	// Embed links inside the request.782	$data = $server->response_to_data( $result, false );783 784	if ( ! class_exists( 'SimpleXMLElement' ) ) {785		status_header( 501 );786		die( get_status_header_desc( 501 ) );787	}788 789	$result = _oembed_create_xml( $data );790 791	// Bail if there's no XML.792	if ( ! $result ) {793		status_header( 501 );794		return get_status_header_desc( 501 );795	}796 797	if ( ! headers_sent() ) {798		$server->send_header( 'Content-Type', 'text/xml; charset=' . get_option( 'blog_charset' ) );799	}800 801	echo $result;802 803	return true;804}