private static function _checkClientCache() { require_once 'HTTP/ConditionalGet.php'; $cgOptions = array('lastModifiedTime' => 0, 'isPublic' => true, 'encoding' => '', 'maxAge' => 1800); $cg = new HTTP_ConditionalGet($cgOptions); if (MINCO_CLIENT_CACHE && $cg->cacheIsValid) { // client's cache is valid $cg->sendHeaders(); return true; } else { // client will need output self::$_headers = $cg->getHeaders(); unset($cg); } return false; }