public function extend_navigation(global_navigation $navigation, navigation_node $modulenode=null) {
        $this->ensure_isset(array('context', 'component'));

        $areas = $this->get_available_areas();
        foreach ($areas as $areaname => $areatitle) {
            $this->set_area($areaname);
            if ($controller = $this->get_active_controller()) {
                $controller->extend_navigation($navigation, $modulenode);
            }
        }
    }