public static function main() { $class = get_called_class(); if (!isset(self::$_instances[$class])) { header('Content-type: text/html; charset=UTF-8;'); self::$_isWeb = !isset($_SESSION['mobile']); self::$_instances[$class] = new $class(); $_SESSION['url'] = $_SERVER['REQUEST_URI']; } return self::$_instances[$class]; }