trying to determine if user is a page admin using FB GraphAPI - facebook

Question

I have a page tab app. When the user clicks on the "Go to App" and is sent to my page tab edit url i am trying to determine if they are a page admin or not.
I have tried two different methods. I have tried from the only admin/owner of the page
method 1 used from https://developers.facebook.com/blog/post/2011/09/05/platform-updates--labor-day-edition/
$page_info = $facebook->api("/".$pageID."?fields=access_token");
$pageAccessToken = $page_info['access_token']
$is_admin_url = "https://graph.facebook.com/" . $pageID
. "/admins/" . $FBuser . "?access_token="
. $pageAccessToken;
$response = file_get_contents($is_admin_url);
response is {"data":[]}
I have also tried::
path = '/'.$pageID.'/admins/'.$FBuser;
$params = array(
'app_id' => FB_APP_ID,
'access_token' => $pageAccessToken
);
$is_admin = $facebook->api($path, 'POST', $params);

Answer 1

Although PAGE_ID/admins is a valid request, you need an admin's access_token to see the list. I.e. only admins can see who else is an admin.
What you can do is approach this from the other end by yielding a list of pages that the user is an admin of (using the https://graph.facebook.com/USER_ID/accounts/ data and the manage_pages permission) and search through that list for your application.
However, I would understand if some users would be reluctant to give the manage_pages permission, as it also provides an access token to authenticate as that page, which would be something of a security hole on their part. Unfortunately, there does not seem to be another way to access a list of pages for which that user is an admin.

Answer 2

Simplest way will be signed Request.
A signed_request parameter is POSTed to an application when the app is loaded inside a Page Tab.
You can get a lot of information from signed_request
require '../fb_sdk/facebook.php';
$config = array();
$config['appId'] = '45916xxxxxx';
$config['secret'] = '59caxxxxxx';
$facebook = new Facebook($config);
$facebook->setFileUploadSupport(true);
$signed_request = $facebook->getSignedRequest();
print_($signed_request); will have output like
Array
(
[algorithm] => HMAC-SHA256
[expires] => 1347210000
[issued_at] => 1347203265
[oauth_token] => AAAGhmv67ki8BAAfBwtxxxx
[page] => Array
(
[id] => 192430xxxxxx
[liked] => 1
[admin] => 1
)
[user] => Array
(
[country] => in
[locale] => en_US
[age] => Array
(
[min] => 21
)
)
[user_id] => 10000020xxxxx
)
You can use $signed_request[page][admin] value to determine whether a user is admin of current page, in which your app in loaded in Page Tab. If it's set to 1 then user is admin of the page else not an admin i.e. set to 0.
More About Signed Request

Answer 3

i had some luck using admin_only = true
https://developers.facebook.com/docs/graph-api/reference/user/groups/