Facebook gat re-permission from user to access additional data - php

Question

I have a file named fbmain.php which will authenticate the user.
<?php
//set facebook application id, secret key and api key here
$fbconfig['appid' ] = "MY_APP_ID";
$fbconfig['secret'] = "MY_APP_SECRET";
$uid = null; //facebook user id
try{
include_once "facebook.php";
}catch(Exception $o){
echo '<pre>';
print_r($o);
echo '</pre>';
}
// Create our Application instance.
$facebook = new Facebook(array(
'appId' => $fbconfig['appid'],
'secret' => $fbconfig['secret'],
'cookie' => true,
));
//Facebook Authentication part
$session = $facebook->getSession();
//Get permission from user
$loginUrl = $facebook->getLoginUrl(
array(
'canvas' => 1,
'fbconnect' => 0,
'req_perms' => 'email,publish_stream,status_update'
)
);
if (!$session) {
echo "<script type='text/javascript'>top.location.href = '$loginUrl';</script>";
exit;
}
if ($session) {
try {
$uid = $facebook->getUser();
} catch (FacebookApiException $e) {
echo "<script type='text/javascript'>top.location.href = '$loginUrl';</script>";
exit;
}
}
//signed_request part
$signed_request = $_REQUEST['signed_request'];
$secret = $fbconfig['secret'];
$data = parse_signed_request($signed_request, $secret);
$fan_page_id = $data['page']['id'];
$admin_check = $data['page']['admin'];
$like_check = $data['page']['liked']; //New
//Get fan page id
function parse_signed_request($signed_request, $secret) {
list($encoded_sig, $payload) = explode('.', $signed_request, 2);
// decode the data
$sig = base64_url_decode($encoded_sig);
$data = json_decode(base64_url_decode($payload), true);
if (strtoupper($data['algorithm']) !== 'HMAC-SHA256') {
error_log('Unknown algorithm. Expected HMAC-SHA256');
return null;
}
// check sig
$expected_sig = hash_hmac('sha256', $payload, $secret, $raw = true);
if ($sig !== $expected_sig) {
error_log('Bad Signed JSON signature!');
return null;
}
return $data;
}
function base64_url_decode($input) {
return base64_decode(strtr($input, '-_', '+/'));
}
?>
I have included fbmain.php file to my index.php file and access user data.
Then later I wanted to access user birthday.So I added 'user_birthday' permission references to the fbmain.php file.code is given bellow
//Get permission from user
$loginUrl = $facebook->getLoginUrl(
array(
'canvas' => 1,
'fbconnect' => 0,
'req_perms' => 'email,publish_stream,status_update,user_birthday'
)
);
code of the index.php file is given bellow,
<?php
//index.php file
include_once "fbmain.php";
$me = $facebook->api('/me');
$_SESSION['id'] = $me['id'];
$_SESSION['name'] = $me['name'];
$_SESSION['link'] = $me['link'];
$_SESSION['email'] = $me['email'];
if($me['birthday'] == null){ ?>
<script>
top.location = 'http://www.facebook.com/dialog/oauth?client_id=MY_APP_ID&redirect_uri=MY_REDIRECT_URL&scope=user_birthday';
</script>
<?php }else{ ?>
//Some other codes
<?php } ?>
I redirect user to permission window requesting user's birthday if $me['birthday'] returns null value. I had to add this part since I added user_birthday to the scope of permission references later.
This works for some users and display 'Request for Permission' window asking to access user's birthday.
But for some users it display a facebook error message(It may since I try to access user's birthday before display 'Request for Permission' window : $me['birthday']==null)
Can anyone tell me a proper way to get the re-permission from user to access user birthday?
Note that this problem occurs only for users those who have already authenticated in my app

Answer 1

You know facebook changed the parameter for the permissions from req_perms to scope in getLoginUrl() function. Try scope, may be it works.
https://github.com/facebook/php-sdk/issues/381

Answer 2

I don't understand php...bt check FB.ui
https://developers.facebook.com/docs/reference/dialogs/oauth/
Here you have oAuth dialog to ask for user permision.

Answer 3

You can use scope params for you requesting permission.
this is code for you want to replace
if ($user) {
$logoutUrl = $facebook->getLogoutUrl();
} else {
$loginUrl = $facebook->getLoginUrl(
array(
'scope' => 'email,publish_stream,user_birthday',
)
);
if you these this code ,your visitor who visit first time this code request full permision ,and already authendicate for other permisions user comes to this page it request only for birthday permisions .
you not need to use
if($me['birthday'] == null){ ?>
<script>
top.location = 'http://www.facebook.com/dialog/oauth?client_id=MY_APP_ID&redirect_uri=MY_REDIRECT_URL&scope=user_birthday';
</script>
<?php }else{ ?>
//Some other codes