XPDL (was Re: XML is broken)

Subject: XPDL (was Re: XML is broken)
From: "Simon St.Laurent" <simonstl@xxxxxxxxxxxx>
Date: Sun, 04 Apr 1999 21:38:07 -0400
The IE5/conformance debates, combined with good questions about style sheet
usage, have driven me to write up a proposal.  In many ways, it's an
alternative to the (also reasonable) approach Chris Lilley describes below.
 (Levels of style sheet alternatives is something I'll have to add...)

I've created a first draft of XML Processing Description Language (XPDL) is
the current result.  For the most part, it's a cleaner replacement for the
prolog, including the style sheet declarations for documents.  Basically,
the concept is that instead of oceans of free-standing documents with piles
of non-content stuff in them, we classify documents as classes of documents
that share resources - constraints, content, style sheets, and
documentation.  Then documents can say "I'm this type of document" instead
of saying "I have this DTD with these modifications that you may or may not
bother loading, and this set of style sheets, with no way to control
processing beyond specifying the encoding."

This is only a first draft, and as such, is incomplete in some areas and
may be questioned in all.  (RDF being a biggie, but this time I've
explicitly reserved space for it.)  The rules for connecting XPDs (XML
processing descriptions) to particular documents are somewhat vague, but I
have reasonable hopes that this proposal is workable, if a departure from
the current approach.

All comments and suggestions are welcome.  If there is enough interest, I
plan to continue developing this with an open model much like that used for
XSchema and SAX.  This is only a first draft intended to incite discussion.
 It is not a part of any formal standards process.

Details are at  http://purl.oclc.org/NET/xpdl .


At 09:01 PM 4/4/99 +0200, Chris Lilley wrote:
>There is a third way
>
>            manifest
>         /  |    |    \
>        x1 img1  ss1  ss2
>
>This allows documents and stylesheets and images and othe rmedia all to
>be reused and to be combined in varous ways.
>
>[...]
>
>Further structure is also desirable
>
>manifest
>  root xml doc
>    subsidiary xml doc1
>    image 1
>    subsidiary xml doc2
>       subsidiary xml doc3
>  stylesheet alternative one
>    stylesheet 11
>    stylesheet 12
>    image 13
>  stylesheet alternative two
>    stylesheet 21
>    stylesheet 22
>    image 23
>
>The mechanism of compound xml documents is clearly transclusion using
>XLink, and for stylesheets, import.


Simon St.Laurent
XML: A Primer
Sharing Bandwidth / Cookies
http://www.simonstl.com


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