Question

So I am using the facebook-php-sdk and I have created a page tab
On the page tab I am trying to use the SDK and it only works when I have logged into facebook as the page not as a user so what would the cause of this be?

require 'facebook-php-sdk/src/facebook.php';
$facebook = new Facebook(array(
    'appId'  => '//APP ID//',
    'secret' => '//APP SECRET//',
));

// Get User ID
$user = $facebook->getUser();

// We may or may not have this data based on whether the user is logged in.
//
// If we have a $user id here, it means we know the user is logged into
// Facebook, but we don't know if the access token is valid. An access
// token is invalid if the user logged out of Facebook.

if ($user) {
    try {
        // Proceed knowing you have a logged in user who's authenticated.
        $user_profile = $facebook->api('/me');
    } 
    catch (FacebookApiException $e) {
        error_log($e);
        $user = null;
    }
}

if(isset($user)) {
    var_dump($user); 
}
else if(isset($user_profile)) {
    var_dump($user_profile);
}
else {
    echo $loginUrl;
}


var_dump($facebook->getUser());

I get this is the error_log: Bad Signed JSON signature

Answer 1

Is the user you are testing with connected to the page (i.e., Liked it)? If not you will not receive any information about who the user is. This is to be expected. Facebook does its best to anonymize the user interaction with pages’ apps when the user hasn’t explicitly Liked the page.