public function getIcalURL($base_url = '', array $params = array()) {

		$user = elgg_get_logged_in_user_entity();

		$params['view'] = 'ical';
		$params['u'] = $user->guid;
		$params['t'] = $this->getUserToken($user->guid);

		$url = elgg_http_add_url_query_elements($base_url, $params);
		return elgg_normalize_url($url);
	}