How to implement Facebook Post Type objects in GAE?

I a new programmer and trying to implement a facebook type "feed" in my application. Like Whenever a user do some changes in his profile his linked profiles will get to know that in the form of news feed.

But I am stuck on that as I thought whenever any user saves any data (like "News", "Blog", "Event" or any "Comment") just send the id of the respective classes to the linked profiles and they will see it. Since the id is not generated before the object is saved , the problem is how can I send them. I thought of following workarounds but each have some problem.

Whenever a user 开发者_StackOverflowposts a news .... a Post object will be made and added to User's Post Collection. But How do the other users will knew about it.....

1) Send them the id .... but when the id is not created how can you send them the id.

2) Send them the post message and when ever they will click them ... the latest post to them from the particular user will be shown.. but if more than 3 messages then which will be shown?? Shown by the post creation Date no post greater than that date is shownn....but he needs to be shown newer posts..

3) Save the post in all followers feed. the data will be much larger then

4) all the followers on login will check all the persons they are following and save their feed after the time stamp? How to implement this as the Post is saved in User's Profile so I would have to check all the following person and then just check the feed and show them on his feed box; I think I would have to use batch Processes. Processing will take much longer.

I am using objectify-appengine to do operations on GAE.

Any help is appreciated

Are you wanting to update the page with posts in real time like on Facebook and Twitter? To achieve this on Google App Engine you can use the Channel API, which works in conjunction with Javascript to listen for new data and update the DOM.

This talk at Google I/O 2009 by Brett Slatkin describes exactly the pattern you should use for this.