Re: [xml-dev] Interoperability

[David Brownell <david-b@pacbell.net>]

Tim Bray wrote:
> At 11:33 AM 14/11/01 -0800, Joe English wrote:
> >Earlier Sean quoted me as saying that I had given up
> >on DTDs.  I haven't at all; what I *have* given up on
> >is <!DOCTYPE ...> declarations.
> ...
> >URLs can break in too many ways.  
> ...
> > Document-relative
> >SYSTEM identifiers are a maintenance nightmare; 
> ...
> >Most importantly: it's very difficult to ensure that the URI
> >for a DTD will last as long as the documents that reference it.
> >Remember the time that Netscape reorganized their web site and
> >all the headline aggregators on the Web suddenly stopped working?
> >This sort of thing is an unacceptable risk.

Well, not all of them -- only the badly written ones that didn't use
local copies of the RSS DTDs.  The risk is using poor systems
design practices, not using correct <!DOCTYPE ...> decls.
(Or using tools/APIs that only support such poor practices ... :)


> All good points.  But I don't think they have much to do with
> interoperability of XML.  You've pointed out what is a horrible
> problem - the infrastructure has really lousy support for 
> dealing with multiple related resourcse that you need to 
> bring together to do a job.  ...
> 
> I've been kind of surprised that there isn't more energy
> being pointed at this problem.  Still am. -Tim

Well, there's the OASIS XML-ized version of SOCAT,
which brings in the SGML approach to catalogs.

And the SAX development list has been discussing how
to improve the current EntityResolver interface, and URI
management in general.  Have a look at:

    http://www.saxproject.org/apidoc/org/xml/sax/ext/EntityResolver2.html

That interface seems like it'll be handy; it should support
that OASIS XML Catalogs stuff, and also make it possible
to validate documents that don't have a <!DOCTYPE...>
(perennial request :).  And I've recently updated AElfred2 to
support that draft API; get the latest code by anon CVS:

    http://www.gnu.org/software/classpathx/jaxp/

So, there has been some recent energy applied.

- Dave

p.s. Sometime soonish I suspect I'll provide a writeup
    on these preliminary "SAX2 extensions 1.1" APIs.
    For now, javadoc at the websit has the info.