How To Load An Activity In A fragment?

How to avoid duplicate content in non-time-sequential infinite-scroll activity stream?

• To implement an infinite-scroll while dynamic activity stream, one problem is to avoid duplicate content. The activity stream is sorted by scores not exactly same as creation time. In Facebook feeds stream, the sequence of content might not be ordered by time. So is Quora. Say, after the first page is loaded by browser or client, while user scroll down, a request is sent to server with the last content ID. So, the server can retrieve content "before" the last content. This works pretty well for time sequential activity. But what about activity stream not time sequential, like popularity sequential. For example, one content is popular and is enrolled in the first page. After a while, its popularity is down and should be in second page. If one client load first page when that content is in first page and the scroll load the second page when its popularity is down, the client behold duplicate content. So, any approach to avoid it?

• Answer:

  Assuming that your feed is assembled in real time, you can just keep a pool of activities that are already shown on the feed.  So, when assembling the feed, just ignore those activities. You can do this easily by passing the shown activity ids when requesting the sequential pages of your feed.