how to tell if user granted your permissions or not with FB.login

Question

I saw a similar question, and it mentions about the change in December 2011, and that part was right

http://facebook.stackoverflow.com/questions/8753085/in-facebook-login-how-do-you-see-the-permissions-that-the-user-granted

but the rest of the answer is wrong

I did notice this is part of the url though

https://s-static.ak.fbcdn.net/connect/xd_proxy.php?version=3&error_reason=user_denied&error=access_denied&error_description=The+user+denied+your+request.#cb= ...

Answer 1

You will not know which permissions the user granted to your application in FB.login callback. You should query permissions connection for user object:

FB.api('/me/permissions', function(response){
  if (response && response.data && response.data.length){
    var permissions = response.data.shift();
    if (permissions.email) {
      alert('User have granted `email` permission');
    }
  }
});

Update:. While it's not stated by Facebook that callback for FB.login will not include perms or scope property which was used before switch to OAuth2 this is the case! There is nothing said in current documentation about permissions passed to callback for FB.login, FB.getLoginStatus or FB.getAuthResponse.

There is also bug report about this behavior which is marked as Won't Fix