public static function enablePageCache($language = 'en', $currency = 'usd') { if (!session_id()) { session_start(); } if (self::canPageCache()) { self::$page_cache_file = Journal2Cache::$path . '/' . Journal2Cache::$dir . implode('_', array(md5(self::getCurrentUrl()), $language, $currency, self::$device)); if (file_exists(self::$page_cache_file)) { echo file_get_contents(self::$page_cache_file); exit; } } }