Unnecessary warning for invalid tokens when calling file_get_contents - php

Question

The following code tries to run file_get_contents for a facebook url based on access token:
$access_token=$ret["oauth_token"];
$fbid=$ret["oauth_uid"];
$url ="https://api.facebook.com/method/friends.getAppUsers?format=json&access_token=$access_token";
try {
$content = file_get_contents($url);
if ($content === false) {
$common_friends = array("error_code" => "something");
} else {
$common_friends = json_decode($content,true);
}
} catch (Exception $ex) {
//Who cares
}
All the Facebook settings are correct, the only potential problem is that the access token is no longer valid. In that case I receive the warning of
file_get_contents(): php_network_getaddresses: getaddrinfo failed:
Name or service not known
How can I upgrade my code, so if the facebook user access token is expired/invalid, file_get_contents will not give a warning, but fail gracefully?
EDIT:
$content = #file_get_contents($url);
still shows the same warning, however, I want to get rid of it. NetBeans also warns me that error control operator is misused. I have modified my code as follows:
try {
User::checkFacebookToken();
//file_get_contents sends warning message when token does not exist
//the problem is already handled, therefore these warnings are not needed
//this is why we set scream_enabled to false temporarily
ini_set('scream.enabled', false);
$content = file_get_contents($url);
ini_set('scream.enabled', true);
if ($content === false) {
$common_friends = array("error_code" => "something");
} else {
$common_friends = json_decode($content,true);
}
} catch (Exception $ex) {
//Who cares
}
I hope that scream.enabled is only temporarily changed to false.

Answer 1

You could alternatively use cURL which has better server response handling and you can display the error gracefully.
$access_token = 'your_access_token';
$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, "https://api.facebook.com/method/friends.getAppUsers?format=json&access_token=$access_token");
curl_setopt($curl, CURLOPT_VERBOSE, 0);
curl_setopt($curl, CURLOPT_HEADER, 0);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
$content = curl_exec($curl);
$response = curl_getinfo($curl);
echo '<pre>';
print_r($response);
if(!curl_errno($curl)){
// Server request success, but check the API returned error code
$content = json_decode($content, true);
print_r($content);
echo $content['error_code'];
echo $content['error_msg'];
}else {
// Server request failure
echo 'Curl error: ' . curl_error($curl);
}
curl_close($curl);
PhpFiddle

Answer 2

SOLUTION 1 : ensure that warnings will not be printed on main output
just add '#' to 'file_get_contents()' to suppress warning since you catched the error correctly by :
error_reporting(E_ERROR | E_PARSE);
if(#file_get_contents() === FALSE) {
// handle this error/warning
}
SOLUTION 2 : verify that you have a valid Facebook token before doing your request, Using Facebook API
$ch = curl_init();
// you should provide your token
curl_setopt($ch, CURLOPT_URL, "http://graph.facebook.com/me?access_token=52524587821444123");
curl_setopt($c, CURLOPT_RETURNTRANSFER, true);
curl_setopt($c, CURLOPT_HEADER, false);
$output = json_decode("[" . curl_exec($c) . "]");
if(is_array($output) && isset($output[0]->error)) {
print "Error Message : " . $output[0]->error->message . "<br />";
print "Error Type : " . $output[0]->error->type . "<br />";
print "Error Code : " . $output[0]->error->code . "<br />";
}else {
// do your job with file_get_contents();
}
curl_close($c);