Stephane Bortzmeyer wrote:
On Mon, Jul 06, 2009 at 12:41:32PM +0100,James Abley <james.abley@xxxxxxxxx> wroteHTTP already provides Cache-Control: / Expires: to indicate how long a client may like to wait before checking if the representation has been updated. Would that meet your requirement?IMHO (I'm not the OP), no. Feed producers (who know the duration of the feed) may not have a way to set HTTP headers. Also, HTTP headers are not end-to-end, they are lost if, for instance, the feed is transferred by non-HTTP means (such as rsync or scp). I would prefer a solution inside the feed.
+1. the update properties of a feed are a property of the feed, not of the protocol. these things are related, but keeping the properties as part of the feed format would make a feed document more self-contained, would allow feed publication in scenarios where HTTP headers cannot be easily set, and might also allow more sophisticated/specialized properties than HTTP's cache control.
thanks for the pointer to RSS 1.0's properties. i am not quite sure whether i like what has been done there, but now that i know that it exists in RSS 1.0, it would be really interesting to know how many feed providers and consumers actually use it, and why it is one of those properties that did exist in some RSS version, but did not make it into Atom...
cheers,
erik wilde tel:+1-510-6432253 - fax:+1-510-6425814
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UC Berkeley - School of Information (ISchool)