facebook api blank response and no exception - php

Question

$facebook = new Facebook(array(
'appId' =>Yii::app()->params['FBappId'],
'secret' =>Yii::app()->params['secret'] ,
));
// Get User ID
$user = $facebook->getUser();
if ($user) {
try {
// Proceed knowing you have a logged in user who's authenticated.
echo $accessToken=$facebook->getAccessToken();
echo '<br/>';
$user_profile = $facebook->api('/me');
print_r($user_profile); echo "normal sdk"; exit;
} catch (FacebookApiException $e) {
echo $e; exit;
$user = null;
}
}
echo "normal sdk end";exit;
i tried with php sdk 3.3.2 and user login by facebook it prints the token and user info untill token expire. after about one hour i check by token debugger session expired and it give exception once and then blank response.but in another tab facebook is being accessed .
my question is
1.When token expired, is there any inbuild method to get valid token again ?
2.Why blank response? everytime it should throw exception

Answer 1

You can use Facebook's Debug Tool to check the validity of your access token.
The normal access token expires in 2 hours, and the extended token lasts for 2 months.
If you want the extended token, go though this: How to extend access token validity since offline_access deprecation
Well, If you are getting blank for $facebook->api('/me'); this simply means that the user have not authorized the app yet. Try something like this-
$user_id = $facebook->getUser();
echo $uid;
if($user_id){
try {
$user_profile = $facebook->api('/me');
} catch (FacebookApiException $e) {
error_log($e);
$user_id = null;
}
}else{
$login_url = $facebook->getLoginUrl();
echo("<br>login url=".$login_url);
};