public function synchronize($forced = false) { if (!$this->isSynchronized or $forced) { self::$lastRequestMethod = 'unixtime'; $diff = Yii::app()->cache->get('hotelbookDifferenceTimestamp'); if ($diff === false or $forced) { $unixtime = $this->request(Yii::app()->params['HotelBook']['uri'] . 'unix_time'); $this->differenceTimestamp = $unixtime - time(); Yii::app()->cache->set('hotelbookDifferenceTimestamp', $this->differenceTimestamp, 30 * 60); } else { $this->differenceTimestamp = $diff; } $this->isSynchronized = true; } }