Re: [mcmanus@appliedtheory.com: Re: Different web pages for different browser versions]

Yup.

Verified. :-] User-Agent is explicitly listed a header that can be used for
content decisions. If it is used
Vary: User-Agent
is the appropriate response to tell the cache what agents can see that
response.

Rob

rfc2616:
see 12.1
==
<!--StartFragment-->The Vary header field can be used to express the
parameters the
   server uses to select a representation that is subject to server-
   driven negotiation. See section 13.6 for use of the Vary header field
   by caches and section 14.44 for use of the Vary header field by
   servers.
==
13.6
==
<!--StartFragment-->
   A server SHOULD use the Vary header field to inform a cache of what
   request-header fields were used to select among multiple
   representations of a cacheable response subject to server-driven
   negotiation. The set of header fields named by the Vary field value
   is known as the "selecting" request-headers.

   When the cache receives a subsequent request whose Request-URI
   specifies one or more cache entries including a Vary header field,
   the cache MUST NOT use such a cache entry to construct a response to
   the new request unless all of the selecting request-headers present
   in the new request match the corresponding stored request-headers in
   the original request.
==

----- Original Message -----
From: "Adrian Chadd" <adrian@creative.net.au>
To: <squid-dev@squid-cache.org>
Sent: Thursday, November 16, 2000 3:14 AM
Subject: [mcmanus@appliedtheory.com: Re: Different web pages for different
browser versions]

>
> can someone with a grasp of the HTTP code verify this? I seem to
> remember it being raised on squid-dev at some time ..
>
>
> Adrian
>
> ----- Forwarded message from Patrick McManus
<mcmanus@appliedtheory.com> -----
>
> Date: Wed, 15 Nov 2000 08:41:57 -0500
> From: Patrick McManus <mcmanus@appliedtheory.com>
> To: Jacob Palme <jpalme@dsv.su.se>
> Cc: wrec@cs.utk.edu, Mikael von Pfaler <mvp@borware.com>
> Subject: Re: Different web pages for different browser versions
> Reply-To: mcmanus@appliedtheory.com
> User-Agent: Mutt/1.2i
>
> this is really http, not whatever the heck wrec is (I just said that
> to get the rhyme in.), but the server should add the
>
> Vary: User-Agent
>
> header to the 1.1 response.. A 1.1 cache knows that only future
> requests with the same user-agent header (and/or any other header(s)
> listed in the vary response header) as the request that generated the
> cached response may be satisified by that cached response. (subject to
> the other normal freshness rules of course.)
>
>
>
> [Jacob Palme: Wed, Nov 15, 2000 at 11:05:00AM +0800]
> > I am not a regular participant of wrec. But I have a question
> > which maybe you have already solved. I tried to look into
> > your archives, but could not find it.
> >
> > The question is that more and more web sites will chech
> > which browser type the user has, and deliver different
> > versions of a web page depending on the browser type.
> >
> > How can proxies handle this, so that you deliver a cached
> > version only if it suits the browser capabilities of the
> > user?
> > --
> > Jacob Palme <jpalme@dsv.su.se> (Stockholm University and KTH)
> > for more info see URL: http://www.dsv.su.se/jpalme/
>
> ----- End forwarded message -----
>
> --
> Adrian Chadd "God: Damn! I left pot everywhere!
> <adrian@creative.net.au> Now I'll have to create Republicans!"
> - Bill Hicks
>
Received on Wed Nov 15 2000 - 15:04:03 MST