[topicmapmail] XML Schema for XTM DTD

[Murray Altheim]

Mary Nishikawa wrote:
> Hi Max,
> 
> This began in topicmapmail and I am sending the reply to one mail list 
> only to avoid cross posts and continue the thread in topicmapmail.
>
> *Max Voskob wrote:
> 
>> Could anyone prove that I'm wrong in my supposition that XTM cannot be
>> legitimately extended thru elements and attributes from other namespaces?
>> Lets say that I want to add a couple more attributes from another 
>> namespace
>> to instanceOf element. I can't see any way how it can be done at the 
>> moment.
[...]
> *M Nishikawa
[...]
> I'm pretty sure that you can import attributes from any namespace, but 
> this would mean your xml would not conform to the  XTM dtd. For example, 
> all of the xlink attributes are not usable in XTM, but you can import 
> them in anyway.

Though, as I mentioned in one of my recent messages, their use is
likely undefined in the XLink specification.

> I think that Murray said something to this effect earlier in a related 
> thread. http://www.infoloom.com/pipermail/topicmapmail/2003q1/004343.html
> Please take a look at related posts from Murray.

XTM was designed as an interchange format, that is, we weren't
creating a W3C-style namespace to be mixed at will with others
in whatever fashion dictated by the needs of the moment, we were
designing a syntax for exchanging topic maps. Full stop.

As Mary has said, I'd prefer not to rehash a discussion that has
occurred many times over the past few years. It was the intent of
the designers and was written into the XTM 1.0 Specification that
it be used as a monolithic namespace, that XTM topic maps
distinctly not be mixed with other namespaces. I'm not sure what
you mean by "prove" within this context. There is no police force
keeping you from mixing the namespace, but you will simply no
longer be in compliance with the spec.

I've yet to see an effective use of markup (for purposes of
interchange or usability beyond one person or organization)
that allowed indescriminate intermixing of namespaces, given
that the receiving party has no idea what to expect. If you
allow "simply" the dozen or so W3C XML-related "core" specs
(XML with full Unicode character support, XML Namespaces, XLink,
XPointer, XSD schema and datatypes, XInclude, XPath, XSLT,
XML Base, XML catalogs, XML stylesheets, DOM level 1 and 2,
etc.), these alone are just about impossible to support,
*before* you begin to add specific markup languages (such as
RDF, RDF Schema, XHTML, XTM, MathML, etc.) into the mix.

I think wistfully back to that initial twenty page XML spec,
and how far away from that we've come. The sorcerer's
apprentice started the process up and now it's gotten out of
hand...

Murray

......................................................................
Murray Altheim                  <http://kmi.open.ac.uk/people/murray/>
Knowledge Media Institute
The Open University, Milton Keynes, Bucks, MK7 6AA, UK

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