I think filtering is a great idea and that it should end up in PSHB one way or the other. So there's not time like now to start talking about possibilities, while the actual implementation will crystallize later.
I myself would like filtering (and processing) to go the way of external filtering services -- the hub would 1) receive a subscription together with a set of URIs pointing to filtering services, 2) receive a notification from the publisher, 3) pass the notification to filtering services, 4) receive the response from filtering services and forward it to the subscriber. Step 3) is intentionally a bit vague since there a lot of ways of doing this, but one could imagine it as "notifying an intermediate subscriber and receiving a new notification in return". I've written about some of these ideas a few months back -- http://izuzak.wordpress.com/2010/01/11/real-time-feed-processing-and-filtering/ (pardon the self-promotion). This would make for a more powerful and open filtering/processing system which of course has it's own drawbacks, so it's maybe something to think about a bit later, after simple filtering implemented within the hub. Cheers, Ivan On Jun 30, 12:09 am, Bob Wyman <[email protected]> wrote: > Now that we've got substantial experience with topic-based PubSubHubbub, I > think it is time we began considering how we would extend the current > protocol to support content-based filtering of topics... We've casually > discussed this in the past, I suggest that we address the subject seriously.
