W3C home > Mailing lists > Public > ietf-http-wg-old@w3.org > September to December 1996

Re: Summary of opinions on Negotiate header

From: Daniel DuBois <dan@spyglass.com>
Date: Mon, 30 Sep 1996 13:34:20 -0700
Message-Id: <2.2.32.19960930203420.00a8da14@rafiki.spyglass.com>
To: Koen Holtman <koen@win.tue.nl>, Larry Masinter <masinter@parc.xerox.com>
Cc: koen@win.tue.nl, http-wg%cuckoo.hpl.hp.com@hplb.hpl.hp.com
>>So why do you need Vary: Negotiate at all? (suggestions on
>><negotiable> later).
>
>Here is an example.  Suppose I have variants in the languages `en' and
>`nl', and that I get
>
> Accept-Language: dk, *;q=0.5
>
>from a user agent.  Now, if the user agent is capable of transparent
>negotiation, I will send a list response (300 response), so that the
>user agent can choose the best variant itself (it may have more
>language preference information than it is sending).  If the user
>agent cannot do transparent negotiation, I will send the `en' variant
>(my `en' variant has a link to the `nl' variant in it anyway).  So in
>this case, just sending
>
> Vary: Accept-Language
>
>is not enough: the response also varies on the header which expresses
>if the user agent can negotiate.

To expand on this, suppose I make

Negotiate: dan

which says "select the best variant by adding the q values" (as opposed to
multiplying the q values like in tcn).  Even though all the Accept,
Accept-langue q's, etc, are the same, the algorithm used to select the
variant has changed, so the response does vary on Negotiate:

It's not just the data, it's the algorithm.

-----
Daniel DuBois, Traveling Coderman         
http://www.spyglass.com/~ddubois/
Received on Monday, 30 September 1996 13:42:03 EDT

This archive was generated by hypermail pre-2.1.9 : Wednesday, 24 September 2003 06:32:14 EDT