Part28: schema population text from Part 21 Annex F

[David Price]

Ed,

Your response to Pascal on both these points are exactly in line with
decisions taken by the P28 project that should not be undone at this point
in time.

Cheers,
David

-----Original Message-----
From: owner-wg11 at steptools.com [mailto:owner-wg11 at steptools.com]On
Behalf Of Ed Barkmeyer
Sent: 16 July 2001 17:34
To: Pascal Huau
Cc: WG11
Subject: Re: Part28: schema population text from Part 21 Annex F


Pascal Huau wrote:

> Yet, one slight issue: you repeatedly use the word "document" when you
talk
> about an XML file. Could you preferably use the term "file" as:
> - sometimes, it is not clear if "document" designates a XML file or Part28
> - "file" might be clearer for a non-expert

Pascal, I don't want to make this change.  In XML, the conforming object is
a "document", not a "file".  Unlike a Part 21
"exchange structure", an XML "document" can explicitly include multiple
"files" (= units of data maintained by operating
systems) and XML elements from other "files" by reference. The change would
be "clearer for a non-expert" only by being
inaccurate/incorrect.

A "Part 28 document" is a "document" that conforms to Part 28 as well as the
W3C XML Recommendation.  The term "document" is
used in Part 28 with the definition from the XML Recommendation -- this
should be made clear in clause 3.  In some places, the
correct reference is to the "iso_10303_28 element", rather than to the
"document" that contains it, but in most places it
doesn't make a difference.  (In a "pure" Part 28 document, they are the same
except for the leading XML directive, but Part 28
also makes rules for iso_10303_28 elements that are included in "larger"
documents.)

> Good issue against Part21 edition 2. I do think we need to consider also
> "the things the referenced instances themselves reference".
> For example, if we reference
> an instance of circle, it would mean nothing to check the validity of the
> circle without checking the validity of the cartesian_point that defines
its
> center.
> My recommendation is therefore that you update Part28, considering
> "references transitivity".

I agree, and I will do that for Part 28, as long as the acting project
leader also agrees.  (I was directed by the committee to
prepare wording to match Annex F of Part 21; we are now proposing wording
that does *not* match, although we believe we are
correcting an error in Part 21.)

Who will submit the SEDS against Part 21?

Thanks,
-Ed

--
Edward J. Barkmeyer                       Email: edbark at nist.gov
National Institute of Standards & Technology
Manufacturing Systems Integration Division
100 Bureau Drive, Mail Stop 8260          Tel: +1 301-975-3528
Gaithersburg, MD 20899-8260               FAX: +1 301-975-4482

"The opinions expressed above do not reflect consensus of NIST,
and have not been reviewed by any Government authority."