>Is there a standard method for providing head information for RSS >feeds?
Isaac: Yep... it's called Conditional GET. The idea is that the server provides ETag and Last-Modified headers on every request, and the client stores them away. The next time the client sends a request, it sends that info back, and the server determines in things have changed since the last request. If there have been changes, the server responds with the feed... if not, it responds with a 304. Here's a couple entries on the subject... me: http://admin.mxblogspace.journurl.com/?mode=article&entry=1853 Pete Freitag: http://www.petefreitag.com/item/235.cfm Mine is a walkthrough of the process, his is more code-specific. Now, there's also a further step you can take to conserve bandwidth, one that is primarily useful with large feeds of rapidly updating info. It's described in RFC3229, which covers delta encoding. Basically, the concept is this: - The client sends an A-IM header with a value of "feed" to the server, along with If-None-Match and If-Modified-Since. (A-IM stands for Accepts-Instance Manipulation.) - The server spots the extra header and recognizes that the client supports feed deltas. - Instead of returning the default feed, the server returns only the entries added/updated since If-Modified-Since. - The server also returns the following with the feed: a "Vary" header set to "If-None-Match", an "IM" header with a value of "feed", and a response code "226 IM Used". Again, this is primarily of interest to high-volume feed producers... the average blog is probably better off saving the extra CPU cycles chewed up by the process than trying to preserve a few extra MB of bandwidth. But on the client side, aggregator developers should try to support it... it requires very little extra code, and can make a big difference in some situations. -- Roger Benningfield http://admin.mxblogspace.journurl.com/ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Message: http://www.houseoffusion.com/lists.cfm/link=i:4:234683 Archives: http://www.houseoffusion.com/cf_lists/threads.cfm/4 Subscription: http://www.houseoffusion.com/lists.cfm/link=s:4 Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=89.70.4 Donations & Support: http://www.houseoffusion.com/tiny.cfm/54
