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Re: User-Agent choice suggestion

From: Gerald Oskoboiny <gerald@w3.org>
Date: Sat, 28 Oct 2000 01:53:00 -0400
To: Terje Bless <link@tss.no>
Cc: W3C Validator <www-validator@w3.org>, Konstantin Riabitsev <graf@relhum.org>, Bjoern Hoehrmann <derhoermi@gmx.net>
Message-ID: <20001028015300.H29138@w3.org>
On Sat, Oct 28, 2000 at 12:58:18AM +0200, Terje Bless wrote:
> On 27.10.00 at 22:33, Bjoern Hoehrmann <derhoermi@gmx.net> wrote:
> >"Konstantin Riabitsev" <graf@relhum.org> wrote:
> >
> >>I use the validator extensively, but I recently started using XML-XSLT
> >>combination and some of my sites generate output depending on the
> >>client's User-Agent string.
> >
> >This is "broken by design". You will have problems [...]
> 
> Yes, but I think perhaps emphasis should be on __by_design__ rather then
> __broken__ here.

I prefer "broken as designed", aka "BAD".

    http://impressive.net/services/dtrt/dtrt?jargon:bad

> It's broken not so much inherently, but rather because it
> will impose a significant burden on the developers to keep the different
> versions in sync and degrading gracefully. However, User-Agent sniffing to
> deliver the most appropriate content to the User-Agent in question can, if
> implemented and maintained well, _improve_ accessability for the site.
> 
> In particular, it's a way to keep the pixelfreaks happy without serving
> utterly borken HTML to users.
> 
> It /can/ be used wrong, but there is nothing inherent to User-Agent
> sniffing that means it /will/ be. Both clients and servers are explicitly
> encouraged to do this anyway for languages and different media types; the
> W3C Validator even does it for GIF vs. PNG!

The W3C validator doesn't do User-Agent sniffing, Apache is doing
regular content negotiation using Accept headers, in a cache-friendly
way.

    http://www.apacheweek.com/features/negotiation
    http://www.apache.org/docs/content-negotiation/
    http://gewis.win.tue.nl/~koen/conneg/

> Anyway, I think the idea has enough merit -- and it's easy enough to
> implement! :-) -- that I'll take a stab at it[0] when I have the time[1].

Sounds good to me, I think it's worth adding.

-- 
Gerald Oskoboiny       <gerald@w3.org>  +1 613 261 6630
System Administrator   http://www.w3.org/People/Gerald/
World Wide Web Consortium (W3C)      http://www.w3.org/
Received on Saturday, 28 October 2000 01:53:10 GMT

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