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Re: [CSS21] Comments on the 2003-09-15 CSS 2.1 Draft

From: Tantek Çelik <tantek@cs.stanford.edu>
Date: Tue, 21 Oct 2003 00:23:36 -0700
To: Boris Zbarsky <bzbarsky@mit.edu>, David Woolley <david@djwhome.demon.co.uk>, <www-style@w3.org>
Message-ID: <BBBA2CBC.2ECC5%tantek@cs.stanford.edu>

On 10/20/03 11:23 PM, "Boris Zbarsky" <bzbarsky@MIT.EDU> wrote:

> 
> 
> 
> David Woolley wrote:
> 
>> It is not really possible to implement CSS with a true tag soup browser,
>> as CSS requires a well defined parse tree.  (On that basis, I believe
>> that NS4 is a tag soup browser with CSS bolted on and IE is a structured
>> document browser with extensive error recovery logic
> 
> See http://ln.hixie.ch/?start=1037910467&count=1 (for Win IE)

Given that tag soup fundamentally doesn't reflect a tree structure, it
should come as no surprise that different teams of programmers would come up
with different approximations.


> and
> 
> http://www.hut.fi/u/hsivonen/soup-dom.html (for Mac IE)
> 
> I'm not so sure this is a "well-defined parse tree" in any sense of the
> word...

Tasman certainly uses a "well-defined parse tree" for valid markup.
However, for tag soup, we simply tried to make sure that common styling
effects worked, and paid very little attention to tag soup DOM.

Getting CSS/HTML default presentation and simple CSS to work with such tag
soup was deemed sufficient.

Why bother trying to make CSS and DOM work properly (or predictably or in a
"well-defined" manner for that matter) with tag soup, when that would simply
encourage authors to depend more on tag soup?  One could even consider
"well-defined" tag soup treatment *harmful*.

Another way of stating this is, for Tasman, fixing bugs with valid HTML/CSS
content was deemed a higher priority than attempting to re-implement tag
soup quirks, except for a *very* few "major" sites which appeared to require
such support.

In fact, with subsequent versions of Tasman
(IE5/Mac...IE5.1...IE5.2...MSN/Mac), in some cases we *dropped* some tag
soup support whenever it got in the way of fixing some sort of standards
support.

After all, isn't it better to wean web authors off of tag soup rather than
continue to encourage them to depend on it by working too hard to make it
work predictably?

Tantek
Received on Tuesday, 21 October 2003 03:20:08 GMT

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