这样的写法是如何形成的

/** * 控制器调度 * */ private static function control() { //二级域名 if ($GLOBALS['setting_config']['enabled_subdomain'] == '1' && $_GET['act'] == 'index' && $_GET['op'] == 'index') { $store_id = subdomain(); if ($store_id > 0) $_GET['act'] = 'show_store'; } $act_file = realpath(BASE_PATH . '/control/' . $_GET['act'] . '.php'); $class_name = $_GET['act'] . 'Control'; if (!@include($act_file)) { if (C('debug')) { throw_exception("Base Error: access file isn't exists!"); } else { showMessage('抱歉！您访问的页面不存在', '', 'html', 'error'); } } if (class_exists($class_name)) { $main = new $class_name(); $function = $_GET['op'] . 'Op'; if (method_exists($main, $function)) { $main->$function(); } elseif (method_exists($main, 'indexOp')) { $main->indexOp(); } else { $error = "Base Error: function $function not in $class_name!"; throw_exception($error); } } else { $error = "Base Error: class $class_name isn't exists!"; throw_exception($error); } }