Inviting a user's Facebook friends to use an app

Question

I'm working on a mobile app with Facebook integration. The app allows the user to create content and send it to their Facebook friends who are also using the app.

In the case where the friend already has the app, it's no problem to send that user a notification. I'm looking for a way to handle the situation where the friend does not have the app. In other words, a way to notify the friend that they can access the content if they get the app.

I'm not sure how to do this. I can't access the friend's email address and I can't see any obvious way to send the friend a private message through Facebook, or post something to their timeline.

Is it possible to email an arbitrary Facebook user if all I know is their user ID?

How have other developers solved this problem?

Thanks.

Answer 1

There is the requests dialog in FBWebDialogs which is specifically for sending invites to use an app.:

[FBWebDialogs presentRequestsDialogModallyWithSession:[FBSession activeSession]
      message:@"message here"
        title:@"title here"
   parameters:nil
      handler:^(FBWebDialogResult result, NSURL *resultURL, NSError *error) {}];