- From: Roy T. Fielding <fielding@avron.ICS.UCI.EDU>
- Date: Sun, 14 Apr 1996 22:35:27 -0700
- To: Koen Holtman <koen@win.tue.nl>
- Cc: http-caching@pa.dec.com, jg@w3.org
Argh, no, you don't need any of this stuff. The Alternates mechanism must be completely orthogonal to Vary. Alternates provides a means for reactive negotiation (i.e., retrieval of a better resource after the first response). Vary provides a means of identifying when the server has engaged in some form of preemptive negotiation. It is both possible and quite reasonable for both to appear in a single response, meaning that the server has chosen what looked to be the "best", but is also providing Alternates so that the user agent can later choose something "better". Vary never affects Alternates and the variant-id part of an EID is only present when receiving a preemptively negotiated response from the server. A server that only supports Alternates will not be serving preemptive responses, and thus will not NEED any variant-ids. ........Roy
Received on Monday, 15 April 1996 05:58:37 UTC