An active access token must be used to query information about the current user

Question

I keep getting the error in the title, while using a simple code:

require_once('sdk/src/facebook.php');
require_once("AppInfo.php");
function idx(array $array, $key, $default = null) {
  return array_key_exists($key, $array) ? $array[$key] : $default;
}
function he($str) {
  return htmlentities($str, ENT_QUOTES, "UTF-8");
}
$facebook = new Facebook(array(
  'appId'  => AppInfo::appID(),
  'secret' => AppInfo::appSecret(),
  'sharedSession' => true,
  'trustForwarded' => true,
));

$arrayForJSON=array();
$user = $facebook->getUser();
$friends = idx($facebook->api('/me/friends'), 'data', array());
if ($friends) {
  $arrayForJSON['friends']=$friends;
}
print_r($friends);

I really don't know how to solve it, I've been searching and trying many answers on stackoverflow

Answer 1

you need to check if already login if not redirect the user to login link

require '../src/facebook.php';

// Create our Application instance (replace this with your appId and secret).
$facebook = new Facebook(array(
  'appId'  => '191149314281714',
  'secret' => '73b67bf1c825fa47efae70a46c18906b',
));

// Get User ID
$user = $facebook->getUser();

// We may or may not have this data based on whether the user is logged in.
//
// If we have a $user id here, it means we know the user is logged into
// Facebook, but we don't know if the access token is valid. An access
// token is invalid if the user logged out of Facebook.

if ($user) {
  try {
    // Proceed knowing you have a logged in user who's authenticated.
   // $user_profile = $facebook->api('/me');
   $friends = idx($facebook->api('/me/friends'), 'data', array());

  } catch (FacebookApiException $e) {
    error_log($e);
    $user = null;
  }
}

// Login or logout url will be needed depending on current user state.
if ($user) {
  $logoutUrl = $facebook->getLogoutUrl();
} else {
  $loginUrl = $facebook->getLoginUrl(array('scope'=>'offline_access'));
}

Answer 2

You need to set the access token to be able to get data or act on behalf of the user. Are you going through a login flow to allow authorization to your Facebook application?

Try the example at https://developers.facebook.com/docs/reference/php/facebook-api/

It provides the very basic login flow that will grant access to the data you're seeking.