Facebook Authentication PHP & AJAX - php

Question

I have a website that first uses the Facebook Javascript API to log a user in. However, when a user sends an xmlhttp request to one of my PHP scripts I would like to check again to see if that user is logged in via PHP (for securities sake).
I had a working system but after a site makeover there seems to be a bug. When I echo $html in the facebook.php script I get this error: {"error":{"message":"An active access token must be used to query information about the current user.","type":"OAuthException"}}.
/* request.js */
var postData = "id=" + id;
sendRequest('assets/php/believe.php',function(req) {
console.log(req.responseText);
},postData);
/* believe.php */
<?php
include("facebook.php");
$id = intval($_POST["id"]);
if($id == '') {
//Stuff
} else {
if($cookie) {
echo "hey";
}
}
?>
/* facebook.php */
<?php
define('YOUR_APP_ID', 'xxxxxx');
define('YOUR_APP_SECRET', 'xxxxxxxxxxxx');
function curl_get_contents($url){
$curl = curl_init();
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($curl, CURLOPT_URL, $url);
$html = curl_exec($curl);
curl_close($curl);
echo "$html";
return $html;
}
function get_facebook_cookie($app_id, $app_secret){
$args = array();
parse_str(trim($_COOKIE['fbs_' . $app_id], '\\"'), $args);
ksort($args);
$payload = '';
foreach ($args as $key => $value){
if ($key != 'sig'){
$payload .= $key . '=' . $value;
}
}
if (md5($payload . $app_secret) != $args['sig']){
return null;
}
return $args;
}
$cookie = get_facebook_cookie(YOUR_APP_ID, YOUR_APP_SECRET);
$user = json_decode(curl_get_contents(
'https://graph.facebook.com/me?access_token=' .
$cookie['access_token']));
?>

Answer 1

I think your code is fine. User access token is expired. If user renews it, the code will work. Make sure you have a valid token in the cookie