title: Get invitable_friends Facebook API iOS
body: <p>I implement an app which need to get list <code>invitable_friends</code> from Facebook. I had researched how to get <code>invitable_friends</code> <strong><em>(have some question like that on stack overflow but I also cannot get any right way to fix it)</em></strong> and also tried but the result always null, I guess the reason is that :<code>The invitable_friends list is only available for games with a Canvas implementation.</code> But I don't know how to integrate Canvas or do somethings else to get the list <code>invitable_friends</code>(sorry, maybe it's a naive way to make a question but I'm not have any experience at this). please let me know the way to get this list(configuration my app on Facebook developer page or do anything).
  Here is my code to get list after login success:</p>
  
  <pre><code>[FBRequestConnection startWithGraphPath:@"/me/invitable_friends"
                                            parameters:nil
                                            HTTPMethod:@"GET"
                                     completionHandler:^(
                                                         FBRequestConnection *connection,
                                                         NSDictionary *result,
                                                         NSError *error
                                                         ) {
                                         /* handle the result */
                                         NSLog(@"resurl");
                                     }];
  </code></pre>