XML interchange [was Re: Stylesheet association]

Several of us were talking yesterday at the GCA XML conference
about the fact that one of the biggest problems with SGML is
still with what's supposed to be one of its key goals: interchange.

It is still way too hard to hand off to someone all the various files
associated with an SGML application in such a way that the recipient
can easily reconstruct it.  SDIF has existed for years, SGML Open's
TR9401 made a simple stab at addressing this in its "Issue B: an
interchange packaging scheme", and then the MIME-SGML work was another
attempt to standardize this, but there appears to be no interoperably
accepted solution.  Some of us feel this is such an important issue
that perhaps it should be the "fourth phase" of the XML effort.

Notice that this issue goes way beyond associating a style sheet,
and I think any XML effort to associate anything with anything will
naturally get us into all these issues, so perhaps we should face
them head on.

> From: Terry Allen <tallen@sonic.net>
> Chris Maden writes:
> | There's been a fair bit of talk on xml-dev about how to associate a
> | stylesheet with a document (James Clark and Terry Allen, at least,
> | have been involved).  It occurs to me that this is pretty simple with
> | one addition to the linking spec.
> | 
> | Right now, there are no predefined values for the role attribute of a
> | locator.  If the predefined value "xml-style" or "xml-stylesheet" is
> | allowed, this indicates that the destination is a stylesheet.  An
> | xlink can be used to associate multiple possible stylesheets with a
> | document.  This method allows an XLG to associate stylesheets with
> | read-only documents.
> Works for me.  This XLG would be in a document other than the read-only
> document.  Extending this idea, this other document could also
> contain all the mappings between xmllink and the read-only document's
> GIs and attribute names (which means that the read-only document
> need not use the xmllink reserved names), and even a summary of
> all the GIs in the read-only document that are EMPTY.  That would
> enable XML (or at least the read-only document) to do without the 
> <empty/> syntax, and potentially make many existing SGML documents 
> valid XML documents.