Discuz中的同步登录

依附于Discuz UCenter的子应用都会有一个选项：

意思很明白了，那它是如何实现的呢？

UC/Control/user.php中有一个onsynlogin方法，这里就是处理同步登录的。

function onsynlogin() {  
        $this->init_input();  
        $uid = $this->input('uid');  
        if($this->app['synlogin']) {  
            if($this->user = $_ENV['user']->get_user_by_uid($uid)) {  
                $synstr = '';  
                foreach($this->cache['apps'] as $appid => $app) {  
                    if($app['synlogin'] && $app['appid'] != $this->app['appid']) {  
                        $synstr .= '<script type="text/javascript" src="'.$app['url'].'/api/uc.php?time='.$this->time.'&code='.urlencode($this->authcode('action=synlogin&username='.$this->user['username'].'&uid='.$this->user['uid'].'&password='.$this->user['password']."&time=".$this->time, 'ENCODE', $app['authkey'])).'" reload="1"></script>';  
                    }  
                }  
                return $synstr;  
            }  
        }  
        return '';  
    }