Real time App with Facebook

Does Facebook provide access to any real time APIs so that you can respond to events as soon as they happen? 开发者_Python百科If not, what alternatives are there and what are their limitations? For example, if I use polling instead, will they limit my api calls? And if I try using RSS feeds, about how much delay can I expect? Or maybe it would be possible to receive and process email notifications (if I could convince a user to forward mail to another email address), as they seem to be dispatched pretty promptly.

I've never tried polling user data, but I think it will work without issues. As far as I know there are no restrictions on the number of API calls you can make on facebook.

As far as the Queries are concerned, what I have seen and I think this is how they implement it. If your query asks for too much data(takes too much time to process is how they measure this I think) - the query will just fail.

eg:
I had this app that would pull all the status messages of all the friends of the user and display it in one place.

I first queried for all the friends of the user - this worked okay.

But at the same time if I ran a loop to get all the status messages for each friend - it would just fail.

I think you can call individual queries without issues, just be careful you query only data you need, cause, if the queries are too big or too many they will just fail.

Best way to findout is running tests yourself.

The Facebook Graph API will allow you to subscribe to real time changes. You can currently only subscribe to users, permissions and errors, but they promise to allow subscribing to more objects in the future.