ecmall前台登陆注册后实现自动跳转到指定页面

用过ecmall注意一下不难发现，在登录注册后都会跳转回原来点击过来的页面。想要实现登陆会注册后跳转到指定页面，比如用户中心，我用了一种很笨的办法：设定登陆和注册的ret_url=http%3A%2F%2F......%2Fnew%2Findex.php%3Fapp%3Dmember，省略号部分用自己的域名代替即可完成上述功能。这种方法笨，却简单。我找到跳转相关的源码，总觉得这种方法不完美，在此贴出源码，忘高人指点迷津。

 function register()
    {
        if ($this->visitor->has_login)
        {
            $this->show_warning('has_login');

            return;
        }
        if (!IS_POST)
        {
            if (!empty($_GET['ret_url']))
            {
                $ret_url = trim($_GET['ret_url']);
            }
            else
            {
                if (isset($_SERVER['HTTP_REFERER']))
                {
                    $ret_url = $_SERVER['HTTP_REFERER'];
                }
                else
                {
                    $ret_url = SITE_URL . '/index.php';
                }
            }
            $this->assign('ret_url', rawurlencode($ret_url));
            $this->_curlocal(LANG::get('user_register'));
            $this->_config_seo('title', Lang::get('user_register') . ' - ' . Conf::get('site_title'));

            if (Conf::get('captcha_status.register'))
            {
                $this->assign('captcha', 1);
            }

            /* 导入jQuery的表单验证插件 */
            $this->import_resource('jquery.plugins/jquery.validate.js');
            $this->display('member.register.html');
        }
        else
        {
            if (!$_POST['agree'])
            {
                $this->show_warning('agree_first');

                return;
            }
            if (Conf::get('captcha_status.register') && base64_decode($_SESSION['captcha']) != strtolower($_POST['captcha']))
            {
                $this->show_warning('captcha_failed');
                return;
            }
            if ($_POST['password'] != $_POST['password_confirm'])
            {
                /* 两次输入的密码不一致 */
                $this->show_warning('inconsistent_password');
                return;
            }

            /* 注册并登陆 */
            $user_name = trim($_POST['user_name']);
            $password  = $_POST['password'];
            $email     = trim($_POST['email']);
            $passlen = strlen($password);
            $user_name_len = strlen($user_name);
            if ($user_name_len < 3 || $user_name_len > 25)
            {
                $this->show_warning('user_name_length_error');

                return;
            }
            if ($passlen < 6 || $passlen > 20)
            {
                $this->show_warning('password_length_error');

                return;
            }
            if (!is_email($email))
            {
                $this->show_warning('email_error');

                return;
            }

            $ms =& ms(); //连接用户中心
            $user_id = $ms->user->register($user_name, $password, $email, $im_msn, $im_qq, $im_phone);

            if (!$user_id)
            {
                $this->show_warning($ms->user->get_error());

                return;
            }
            $this->_hook('after_register', array('user_id' => $user_id));
            //登录
            $this->_do_login($user_id);
            
            /* 同步登陆外部系统 */
            $synlogin = $ms->user->synlogin($user_id);

            #TODO 可能还会发送欢迎邮件

            $this->show_message(Lang::get('register_successed') . $synlogin,
                'index.php?app=member', 'index.php?app=member',
                'enter_member_center', 'index.php?app=member',
                'apply_store', 'index.php?app=apply'
            );
        }
    }