CodeIgniter框架 index.php执行顺序

[php]代码库

require(BASEPATH.'core/Common.php');

// Common.php主要是load_class()加载各种所需的类库
// 比如加载配置文件类什么的 
$CFG =& load_class('Config', 'core');
$URI =& load_class('URI', 'core');
$RTR =& load_class('Router', 'core');
$RTR->_set_routing();
$SEC =& load_class('Security', 'core');
$IN	=& load_class('Input', 'core');

require BASEPATH.'core/Controller.php';
function &get_instance()
{
	return CI_Controller::get_instance();
}

// 从$RTR类解析出URL的 class 名与 method 名
$class  = $RTR->fetch_class();
$method = $RTR->fetch_method();

call_user_func_array(array(&$CI, $method), array_slice($URI->rsegments, 2));