Q:

Get real-time notification from Facebook for user updates

I am building a website app using Facebook PHP API. My current scenario is I want my server side to get updates from Facebook when a user of mine app(he already give the access_token) has some updates. e.g.: if the user post a comment, if someone post a comment on his wall, send him a message, I wish in my server side I can get this notification. 
I have checked out the graph API's realtime updates, but I didn't get if I can use the realtime updates to do the above tasks. I wonder if someone know if the realtime updates can do this or not. 
The second solution would be: since I have the access_token, I can periodically check the information of the user to see if there is any new updates. The disadvantage of this approach is that it puts lot of heavy on my server side. 

A:

The real-time updates API documentation says:
"You can't subscribe to these user connections yet: home, tagged, posts, photos, albums, videos, groups, notes, events, inbox, outbox, updates, accounts. We will add support for more properties and connections in the future."
The three examples you listed are all not available at the moment. For now, you will need to poll the Graph API every so often to check.  You will want to prompt the user for offline_access extended permission to be able to check this later after they leave your site.

