public function add_url_params(moodle_url $url) {
        if (empty($this->type)) {
            return $url;
        }

        $url->param('gpr_type', $this->type);

        if (!empty($this->plugin)) {
            $url->param('gpr_plugin', $this->plugin);
        }

        if (!empty($this->courseid)) {
            $url->param('gpr_courseid' ,$this->courseid);
        }

        if (!empty($this->userid)) {
            $url->param('gpr_userid', $this->userid);
        }

        if (!empty($this->groupid)) {
            $url->param('gpr_groupid', $this->groupid);
        }

        if (!empty($this->page)) {
            $url->param('gpr_page', $this->page);
        }

        return $url;
    }