facebook登录bug使用fb php sdk

Question

My problem is the following. I have a website http://de.gamercharts.com/

You can connect with facebook(if you don't have an account,an account will be created). After this ,if you logout from the site ,you are logged out from facebook too. Everything is ok so far. The problem is that if I am logged out of the site (let's call the site GC) and logged out of facebook ,when I click "connect with facebook" on the site,I get logged in on the site,instead of being prompted to the facebook login screen. When I print the user ,I see that even though I am logged out of facebook,I still have the user id. Why does this happen,and how can I fix it ? Thanx a lot to anyone who takes the time to answer. For the record I am using Zend ,although I don't think it's relevant. I did not implement the facebook login myself,I am continuing the work of someone else.

Answer 1

The problem is caused due to existence of Facebook Session Variables in your domain/site, even after logging out from facebook and your site. When someone logs out from your site, one should take care to destroy all the sessions[even facebook sessions]. For destroying facebook sessions in your domain/site, you can make use of the function destroySession(); [provided in the facebook php sdk] in your logout script.

 $config = array();
 $config['appId'] = 'YOUR_APP_ID';
 $config['secret'] = 'YOUR_APP_SECRET';
 $facebook = new Facebook($config);
 $logout = $this->facebook->getLogoutUrl(array('next'=>'url to be redirected after logout'));
 $facebook->destroySession(); // To destroy facebook Sessions
 $session_destroy(); //To destroy sessions of your site
 header("Location:$logout");

P.S Don't forget to include or call session_start() in the script