How to log out users using Facebook Connect in PHP and Zend?

I am trying to build a Connect app using PHP and the Zend Framework.
I also have a Zend_Auth based user authentication system.
Now, I am able to log in using Facebook but log out is not working.

I need to clear the Zend_Auth identity as well as remove all Facebook login info.
What would be the best way to do this?

I tried `facebook_client->expire_session()` and `facebook_client->clear_cookie_state();` together and also `facebook_client->logout($next)` after calling `Zend_Auth::getInstance()->clearIdentity()`

None of them seem to work.

You have to call the javascript client logout *first*, then send them to your php logout script. So, call .js:

FB.Connect.logoutAndRedirect("/path/to/zend/logout/controller");

You'll see a modal popup that says "you are logging out of this site and facebook* You'll be redirected to wherever your logout script is:

try
{
$facebook->expire_session();
}
catch (FacebookRestClientException $e)
{
//you'll want to catch this
//it fails all the time
}

I usually also call this function in the PHP logout script, just to be safe:

/**
* Remove the local Facebook cookies that get set manually
*
* @return void
*/
protected function _killFacebookCookies()
{
// get your api key
$apiKey = $this->getConfig()->getApiKey();
// get name of the cookie
$cookie = $this->getConfig()->getCookieName();

$cookies = array('user', 'session_key', 'expires', 'ss');
foreach ($cookies as $name)
{
setcookie($apiKey . '_' . $name, false, time() - 3600);
unset($_COOKIE[$apiKey . '_' . $name]);
}

setcookie($apiKey, false, time() - 3600);
unset($_COOKIE[$apiKey]);
}

You can logout the facebook user and redirect the user to your website page with PHP code like this :

header("Location: " . $facebook->getLogoutUrl(array('next'=>"http://yourwebsite.com/redirectAfterFacebookLogout.php")));

(NEW FACEBOOK SDK)
For me the getconfig() wouldn't work.So I had to find the new functions from the base_facebook.php file and add this bit of code in it.
Then call it in your calling file. Before you do , call $facebook->destroySession();

public function _killFacebookCookies()
{
// get your api key
$apiKey = $this->getAppId();
// get name of the cookie
$cookie = $this->getSignedRequestCookieName();

$cookies = array('user', 'session_key', 'expires', 'ss');
foreach ($cookies as $name)
{
setcookie($apiKey . '_' . $name, false, time() - 3600);
unset($_COOKIE[$apiKey . '_' . $name]);
}

setcookie($apiKey, false, time() - 3600);
unset($_COOKIE[$apiKey]);
}

You have to call the javascript client logout *first*, then send them to your php logout script. So, call .js:

    FB.Connect.logoutAndRedirect("/path/to/zend/logout/controller"

You'll see a modal popup that says "you are logging out of this site and facebook* You'll be redirected to wherever your logout script is:

    try
    {
        $facebook->expire_session();
    }
    catch (FacebookRestClientException $e)
    {
        //you'll want to catch this
        //it fails all the time
    }

I usually also call this function in the PHP logout script, just to be safe:

    /**
    * Remove the local Facebook cookies that get set manually
    *
    * @return void
    */
    protected function _killFacebookCookies()
    {
        // get your api key
        $apiKey = $this->getConfig()->getApiKey();
        // get name of the cookie
        $cookie = $this->getConfig()->getCookieName();
       
        $cookies = array('user', 'session_key', 'expires', 'ss');
        foreach ($cookies as $name)
        {
            setcookie($apiKey . '_' . $name, false, time() - 3600);
            unset($_COOKIE[$apiKey . '_' . $name]);
        }
               
        setcookie($apiKey, false, time() - 3600);
        unset($_COOKIE[$apiKey]);     
    }

Thanks, seems to be the correct solution. If it was for Youtube/Gmail/Etc. it has a small url that does logout.