Same facebook problems … OAuthException: An active access token must be used to query information about the current user

Question

So this is working fine... But when I refresh the page twice(or click on two pages who include this script fast) it gives this error OAuthException: An active access token must be used to query information about the current user. Any ideas?

<?php

  $app_id = '***************';
  $app_secret = '**************';
  $app_namespace = '****************';

  $app_url = 'http://apps.facebook.com/' . $app_namespace . '/';
  $scope = 'email,publish_actions';

  // Init the Facebook SDK
   $facebook = new Facebook(array(
     'appId'  => $app_id,
     'secret' => $app_secret,
   ));

   // Get the current user
   $user = $facebook->getUser();

   // If the user has not installed the app, redirect them to the Login Dialog

   if (!$user) {
     $loginUrl = $facebook->getLoginUrl(array(
       'scope' => $scope,
       'redirect_uri' => $app_url,
     ));

     print('<script> top.location.href=\'' . $loginUrl . '\'</script>');
   }

if ($user) {
  try {
    // Proceed knowing you have a logged in user who's authenticated.
    $user_profile = $facebook->api('/me', 'POST');
  } catch (FacebookApiException $e) {
    error_log($e);
    $user = null;
  }
}
//<img src="https://graph.facebook.com/?php echo $user; ?/picture">
//?php print_r($user_profile); ?
?>

Answer 1

I personally find it easier to manage the access_token myself. Facebook's Graph API secures protected endpoints by requiring that an access_token be passed in. The PHP SDK abstracts this away, but I have never been comfortable with Facebook handling the information because sometimes it just doesn't work . This isn't to say that the library is bad, but only that I haven't been using it correctly . Keep this caveat in mind.

It looks like you're working with a Facebook Canvas App. When the user successfully authenticates for the first time, Facebook will send an access_token in $_GET . At this point, you should save this to your database, since that access token is good for 3 months or so.

At the point, from then on, you can pass in the access_token in the call parameters:

try {
    $user_profile = $facebook->api('/me', 'POST', array(
        "access_token" => ''    // access token goes here
    ));
} catch (FacebookApiException $e) {
    // error handling
}

Given that Facebook is returning the error that you need an access token in order to call the /me resource, it looks like $facebook->getUser(); is returning something. You may want to double-check what it is.

---

While I'm here, you're using this logic:

if (!conditional) {
    // do something
}
if (conditional) {
    // do something else
}

Confusing. Use else :

if (conditional) {
    // do something
} else {
    // do something else
}