Re: SGML macros using DSSSL expressions

Paul Prescod (papresco@itrc.uwaterloo.ca)
Wed, 28 Feb 1996 17:08:58 -0500


Date: Wed, 28 Feb 1996 17:08:58 -0500
Message-Id: <199602282208.RAA07509@undergrad.math.uwaterloo.ca>
To: "Harold A. Driscoll" <harold@driscoll.chi.il.us>
From: Paul Prescod <papresco@itrc.uwaterloo.ca>
Subject: Re: SGML macros using DSSSL expressions
Cc: Erik Aronesty <erik@inch.com>, connolly@beach.w3.org, www-html@w3.org

At 09:33 PM 2/28/96 +0000, Harold A. Driscoll wrote:
>For example, if I want to keep a list of HTML Internet Drafts, I'd like to
>code something like this (excuse c++ syntax, but it is familiar to many):
>
>&draft( draft-ietf-html-tables-06.txt, HTML Tables )
>&draft( draft-ietf-html-style-01.txt, HTML and Style Sheets )
>&draft( draft-ietf-html-i18n-03.txt, Internationalization of the HyperText
>Markup Language )

Does your language support recursion?  
What about nesting?
How do I validate your document?  Do I need to run it through a preprocessor?

There is a whole bunch left to specify.  And there is no reason to do so.
We do not need an extension to HTML (or SGML).  I do this sort of thing all
of the time.

<HTMLDRAFT SRC="draft-ietf-html-tables-06.txt" Title="HTML Tables">
<HTMLDRAFT SRC="draft-ietf-html-style-01.txt" Title="HTML and Style Sheets">
<HTMLDRAFT SRC="draft-ietf-html-il8n-03.txt" Title="Internationalization of
the HyperText Markup Language">

You'll notice that my version is a little more explicit, doesn't require any
"standard" macro language, and uses the standard SGML parser for validation.
Of course, you must do a transformation from this into something "viewable".  

Right now the best bet is server-side transformation.  You can use the
language of your choice, and do much more powerful transformations than a
toy macro language would allow.

In the near future, we can use style sheets. Instead of specifing yet one
more difficult thing for browser writers to implement, we could just force
them to display arbitrary SGML markup and your problem goes away.  Anything
that you would have specified in your macro language would go in the style
sheet.  From what I have heard, DSSSL is a nice combination of a style sheet
language and client-side transformation engine.  It would allow complex
transformations that macro languages could not touch.

In the meantime you can use server-side conversion to transform documents
from your format into standard HTML so that the browser writers can save
their efforts for writing powerful style sheet engines.

 Paul Prescod