退出Facebook（使用PHP SDK）和CodeIgniter

Before I started implementing Facebook authentication, my logout controller looked like this:

# Kill the session
$this->session->sess_destroy();

# Redirect back to main page.
redirect('', 'location');

I tried modifying it to log the user out of Facebook as well, but no luck.

# Kill the session
$this->session->sess_destroy();

require 'application/sdk/facebook.php';

// Create our Application instance (replace this with your appId and secret).
$facebook = new Facebook(array(
  'appId'  => '625256',
  'secret' => '25256256',
  'cookie' => true,
));

$session = $facebook->getSession();

if ($session) {
    $location = (string) html_entity_decode($facebook->getLogoutUrl(array('next' => 'http://localhost:8888/taketocollege/')));
    header("Location: $location");
    exit();
}

# Redirect back to main page.
redirect('', 'location');

What am I doing wrong? I'm not looking to use the Javascript SDK for this since I want it all to be done in the controller.

Thanks!!

EDIT: To be a bit more clear, the problem is that the session isn't being destroyed. My logout controller sends users to the home page, but the home page redirects Facebook users with a session to the login page. So the Facebook users end up on the login page. Normally the login page would automatically log them in, but, by then, their session is destroyed.

My code initially redirected users to the home page.

$session = $facebook->getSession();

$me = null;
// Session based API call.
if ($session) {
  try {
    $uid = $facebook->getUser();
    $me = $facebook->api('/me');
  } catch (FacebookApiException $e) {
    error_log($e);
  }
}

if($session && !$this->session->userdata('logged_in'))
    redirect('login');

That code was redirecting users to the login page since the session had been changed, not completely erased.

By changing the last two lines, I was able to fix this problem:

if($me && !$this->session->userdata('logged_in'))
    redirect('login');

Hope it helps someone!

What you have here is : a "Logout" button that points to your logout controller and you are trying to make your logout controller call something to make the user logout from Facebook.

If you log in your users with Facebook, you don't need logout controller. You just display the logout URL in your page :

$args['next'] = "http://localhost:8888/taketocollege/";
$logoutUrl = $facebook->getLogoutUrl($args);
echo '<a href="' . $logoutUrl . '">Login with Facebook</a>';

If you want to clear the session when the user logs out, you wan do it on the next page (for you, http://localhost:8888/taketocollege/) :

require "facebook.php";
$facebook = new Facebook(array(
    'appId'  => YOUR_APP_ID,
    'secret' => YOUR_APP_SECRET,
));

$user = $facebook->getUser();

if (!$user) {
    $this->session->sess_destroy();
}

Hope that helps !