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Re: Indicating browser support for XHTML1.0

From: Chris Haynes <chris@harvington.org.uk>
Date: Thu, 22 Nov 2001 14:06:41 -0000
Message-ID: <00e601c1735e$e9633e80$0200000a@RINGO>
To: "www-html" <www-html@w3.org>
Dear list,

Thanks for all the help I've received.

I'm not asking this list for help with my coding - that's off topic
and totally inappropriate for such an august forum.

What I am attempting to do is explain to you the logic leading me to
the conclusion that some kind of standardised version negotiation
between source and browser is becoming necessary if there is to be a
rapid migration to the more recent standards.

Some of you suggest I should be able to write 'compatible' code -
spanning HTML4.01 and XHTML1.0.

Syntactically, this is so (and I had already worked out how to do this
with the aid of the excellent XHTML1.0 documentation and validation
suite you have produced).

The problem actually comes with controlling on-screen layout. I have
not found a single way to describe the layout I need (align, valign,
margin-size etc.) which is correctly rendered by both pre-and
post-generation 6 browsers.

HTML4.01 still permits me to use tag attributes like 'align' (which is
what I need to use for the 'legacy' browsers as their CSS support is
inadequate).

XHTML1.0 requires me to use the CSS2 equivalent styles (which I have
done - and works fine in the Generation 6 browsers).

It is this discontinuity in layout control which requires me to
distinguish whether or not I am generating code for an
XHTML1.0-capable browser (given that my policy is to use the latest
viable standard wherever possible).

Since it appears that no one seems close to specifying a workable
version-indication standard, my options seem to be:

1) Stick to generating HTML4.01 for the next 5 years or so until all
my target market has migrated to generation 6+,

2) Continue parsing the UserAgent strings and maintaining my own
'compatibility' register.

(BTW, I parse all the UA info and decode the aliases and morphing
undertaken by Opera and MSIE - I don't just look at the 'proper'
browser type).

I can see that considerable attention and ingenuity is applied to the
standards to take account of migration, and it must be frustrating
that browser vendors do not seem capable of keeping up.

Sadly, in this 'real world' it is the actual browsers, not the
standards, that people have to work with.

I don't believe that the 'purity' of standards is compromised by
making provisions for the inability of the vendors to be accurate,
comprehensive and timely, or of the markets  to adopt every innovation
as soon as it is available

If I may observe, as a professional  engineer with 35 years industrial
experience in the defense, computer and telecomms industries, it
appears to me that the lack of support for negotiating version levels
could soon lead to even greater difficulties for the (X)HTML
community.

I can't think of any other sphere of engineering which has survived
rapidly-evolving interface standards without suppliers and clients
being able to negotiate (or at least validate) interface version
compatibility.

Looking at the work you are doing on XHTML1.1. and 2.0, with other
'goodies' like XForms coming down the track, the scope for
unmanageable syntactic and semantic discontinuities seems enormous
(much greater that the 'layout' one I have stumbled over).

Masayaso Ishikawa has kindly told me about some of the versioning
capabilities that have been considered in the past - but not
implemented, as I understand it.

Need any help?

Chris Haynes
Received on Thursday, 22 November 2001 09:08:31 GMT

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