In FB api v2.0+, can non-game app use apprequests https://developers.facebook.com/docs/games/requests/v2.2#implementation? I tested that our app which is categorized as shopping app seems to be able to use apprequests without problem when switching to FB v2.1, however on the link of https://developers.facebook.com/docs/games/requests/v2.2#implementation, it says "Requests are available for games on Canvas, iOS or Android.". Why my test shows apprequests api works for FB v2 for my shopping app, but the documentation says it only work for Game app?
There is in fact a current hole in the Facebook API regarding web invites to non-game canvas apps. The Facebook API changelog from v 2.2 to v 2.3 states that the apprequests function that opens the Request Dialog is now only limited to games, and that non-game apps should use App Invites. However, App Invites work only in iOS and Android.
Trying to render the Request Dialog for a non-game app will fail with an error indicating it is available for game apps only. So currently, there is no way for users to invite friends to a non-game canvas app via the web, except by using the Send Dialog which is a lousy user experience and really shouldn't be used for that.
I have filed a bug report with Facebook and they have acknowledged it is a valid bug. Let's hope they fix it soon.
来源：https://stackoverflow.com/questions/27949729/can-non-game-app-use-fb-apprequests-dialog-in-fb-v2