php - Facebook $facebook->getUser() is not working -

we trying user information getuser() method of facebook using php sdk (3.1.1) returns 0. cause?

$facebook = new facebook(array(   'appid'  => $fbconfig['appid'],   'secret' => $fbconfig['secret'],   'cookie' => true, )); $facebook->getuser(); 

the latest sdk v.3.2.2 https://github.com/facebook/facebook-php-sdk/ should use instead , using login handling logic getloginurl()