Facebook注销无法与PHP SDK一起使用

Question

I know this has been asked many times before and I've spent about 2 hours now trawling through every other answer and trying out solutions and none of them have worked. Basically the problem is I am using the Facebook PHP SDK to log my user in. That bit is fine. When I want to log the user out of my site and Facebook though it doesn't work. My site is built in codeigniter if that affects anything. Here is what I have:

$this->load->library('facebook');
$logout_url = $this->facebook->getLogoutUrl(array('next' => site_url()));
redirect($logout_url);

This user gets redirected ok but if I go to facebook.com I am still logged in. This should log the user out of facebook as well should it not? I have tried alsorts such as clearing the native php session, unsetting cookies etc. like so:

$config = array(
    'appId'  => FB_APP_ID,
    'secret' => FB_APP_SECRET,
    'fileUpload' => true, // Indicates if the CURL based @ syntax for file uploads is enabled.
);

$this->load->library('facebook', $config);

setcookie('fbs_'.$this->facebook->getAppId(), '', time()-100, '/', $_SERVER["SERVER_NAME"]);
unset($_SESSION['fb_'.$this->facebook->getAppId().'_code']);
unset($_SESSION['fb_'.$this->facebook->getAppId().'_access_token']);
unset($_SESSION['fb_'.$this->facebook->getAppId().'_user_id']);
unset($_SESSION['fb_'.$this->facebook->getAppId().'_state']);

$logout_url = $this->facebook->getLogoutUrl();

$this->facebook->destroySession();

try {
    $this->facebook->destroySession();
    setcookie('fbs_'.$this->facebook->getAppId(), '', time()-100, '/', base_url());                 
} catch (Exception $e) {
    //$this->facebook->clearAllPersistentData(); Protected method
}
$this->session->sess_destroy();

So the only thing I can think is that there is a bug with Facebook at their end and its not logging out when it should. Anyone know if this is the case?

Answer 1

Codeigniter doesn't use native PHP sessions - CI stores sessions in a cookie. You can read about it here .

Facebook, however, does use native PHP sessions. So what you'll find is destroying the Codeigniter session won't destroy the Facebook session.

You could try something like this:

// Destroy CodeIgniter Session 
$this->session->sess_destroy();

// Destroy Facebook Session using Facebook function
$this->facebok->destroySession();

// Maybe even destroy all native sessions as overkill
session_destroy();

I imagine after doing this, there's no way the session will/can still persist. This happens all the time with PHP and Codeigniter. See: logout facebook connect session

Answer 2

I fixed my issue by commenting out the line below. Now my users can logout.

$this->facebook->destroySession();