Re: HTML style sheets

H&kon W Lie (howcome@dxcern.cern.ch)
Wed, 9 Nov 1994 13:15:56 --100


Date: Wed, 9 Nov 1994 13:15:56 --100
Message-Id: <9411091215.AA21114@www4.cern.ch>
To: "C. M. Sperberg-McQueen" <cmsmcq@uic.edu>
Cc: www-html@www0.cern.ch
Subject: Re: HTML style sheets
In-Reply-To: <9411042158.AA18682@dxmint.cern.ch>
From: "H&kon W Lie" <howcome@dxcern.cern.ch>

[by now, all new subscribers of www-html should be on the list even if
the got an error messag back when subscibing]

C. M. Sperberg-McQueen writes:

 > All agreed.  I'd put the final point even more strongly:  they should
 > not be referenced from the HTML *document* at all; the link should be
 > external to the document, established in the HTTP header, not within
 > the HTML document.

Why? Technical or political reasons? Removing it from the document
would take influence away from the author and hand it over to the
maintainer of the server. When the mainatainer is a publishing house,
this may make sense, but probably not for a university student's
welcome pages.

 > > o Should style sheets be HTML-specific or SGML-generic?
 > 
 > Generic.  What gain is there to making them HTML-specific?

You have a limited set of tags that can be (ughh) hardcoded into the
parser. Also, one can make some shortcuts by creating convenience
groups (e.g. all header elements) for setting presentation parameters.

 > Basis to use for syntax.  (Should the style sheet be an SGML document
 > using a specialized style-sheet DTD?  I like this one a lot, since it
 > means we can use standard SGML editors for it.  A data structure in
 > some existing notation?  A C structure?  A Scheme S-expression?  I
 > like the notion of using Scheme, since it is used in DSSSL and is
 > clean and simple.  A program or expression in an ad hoc language we
 > devise?  This has the appeal of allowing the inventor the pleasure of
 > inventing a new language, but otherwise doesn't have much to recommend
 > it.)

My concern is with the people who will write the style sheets. Just
like HTML was simple enough for people to write using emacs, the style
sheet language should also not require special tools.

Let's start in the other end: how do humans convey stylistic
preferences? A quite normal statement in english is "I like red." I
this this is a perfectly fine style sheet that future browsers should
understand. Of course, this is not a complete style sheet, but blended
with e.g. the author's stylistic preferences, one could create a
decent presetation.

Now, we probably do not want to base our style sheet language on the
english language, but I do think we can find a little language that 

 - people feel more comfortable in
 - requires a very simple parser
 - has the same or higher functionality (in the context of style
   sheets) as SGML

 > I hope to have a better list soon, after working through the DSSSL
 > spec.  The items above are just a summary of what I came up with
 > trying to devise a set of primitives to describe the behavior of
 > HTML browsers as described in the HTML specification.  (Original
 > text is at http://tigger.cc.uic.edu/~cmsmcq/style-primitives.html)

Thanks. I've added this to the style page
(http://info.cern.ch/hypertext/WWW/Style/)

Is the DSSSL spec publicly available? Through a URL?

-h&kon

Hakon W Lie, WWW project, CERN, CH-1211 Geneva 23
http://info.cern.ch/hypertext/WWW/People/howcome/