在Facebook Connect上处理用户注销

Question

I am facing an error with my web app that uses Facebook connect that occurs when the user has both my web app open and Facebook.com open and logs out of Facebook.com. Since my app and the Facebook Connect library is unaware that the session is no longer valid, when it tries to user certain Facebook Connect functions that require a valid session, I get a 'FacebookRestClientException' with message 'Session key invalid or no longer valid.' Just wondering what the best practice is for handling this case for a php app.

From Googling I found that there's a JS function that pings the Facebook server to see if a user is logged in but I need a server side solution.

Answer 1

use:

$fb_user=$facebook->get_loggedin_user();

this will tell you the facebook_uid of the logged in user or return false if not logged in.

example:

$fb_user=$facebook->get_loggedin_user();

if($fb_user)
{
    try{
        $setstatus = $facebook->api_client->users_setStatus(
            $status,
            $facebook_uid
            );
        echo 'status has been updated';
    }catch (Exception $e) {
        if($e->getCode() === 102)
        {
           // user is not logged in
           echo 'you must log in to update your status';
        }
        log_error($e->getMessage()); // log your error so you can fix it if you need to
    }
}else{
    echo 'you must log in';
}