[
Lists Home |
Date Index |
Thread Index
]
- From: "Frank Biz" <fscheng@netzero.net>
- To: <xml-dev@ic.ac.uk>
- Date: Thu, 2 Dec 1999 11:22:14 -0600
I'm fairly new to this community. Please help me answer this very simple
question.
Thanks,
Frank.
----- Original Message -----
From: "David Megginson" <david@megginson.com>
To: <xml-dev@ic.ac.uk>
Sent: Thursday, December 02, 1999 8:39 AM
Subject: Re: Object-oriented serialization (Was Re: Some questions)
> Matthew Gertner <matthew@praxis.cz> writes:
>
> > A schema gives you this information too. The problem of how to attach a
> > schema to an instance is not yet resolved, but it is a purely syntactic
> > consideration and a satisfactory solution will be found. This then tells
> > you what class a given instance belongs too. The identity can be
> > specified using an ID attribute; this is exactly the way it is done in
> > RDF. That an element represents a relationship is implicit in the
> > content model of the element.
>
> I still don't follow. Perhaps I need to reread the XML Schema spec,
> but given
>
> <foo>
> <bar id="xxx">
> <hack>David</hack>
> <flurb>Megginson</flurb>
> </bar>
> </foo>
>
> How does the schema tell me that foo represents a container for a
> collection of objects, bar represents an object, and hack and flurb
> represent the object's properties?
>
> > SAX is great as far as it goes, but we seem to be agreeing that an
> > additional layer is needed on top. This layer is not the DOM.
>
> It can be. The DOM represents a domain-specific object layer that is
> useful for a wide subset of XML operations (especially document- and
> browser-oriented work). There need to be many layers on top of XML,
> one for each domain -- it happens that many of those layers will share
> the need to encode objects, so a standard object layer sandwiched
> between XML and the domain-specific layers can save a lot of work.
>
> > There are a variety of efforts to create
> > domain-specific objects automatically from XML objects. I don't have a
> > list at the tips of my fingers, but if anyone does it would be a great
> > resource. They are out there because I keep bumping into them.
>
> One example is RDF.
>
> > To be quite blunt it seems ashame that a lot of really great work is
> > being put into the RDF effort (including a very valuable vocabulary
> > for collection classes, just to name one) instead of being
> > integrated more tightly into the overall XML architecture.
>
> I disagree strongly with the last part of that statement. I'd argue
> the opposite -- higher-level layers should be as independent of XML as
> possible. That's the only way to build good, layered architectures.
> XML does one thing (represent a tree structure in a character stream)
> very well: it's an excellent layer to build other layers on top of,
> but XML itself should stay as simple as possible so that it's
> applicable widely to many different fields.
>
> > I think that if the work being done on RDF were refocused to making
> > sure that XML Schemas do everything that the RDF advocates are
> > rightly claiming is necessary, that we will see a clear win in terms
> > of pushing the whole XML effort from a theoretical effort into a
> > major paradigm shift with extensive real-world implications.
>
> That would be another serious mistake. Object exchange, while
> important, represents only one of many layers that can be build on top
> of XML, and if XML Schemas start trying to solve high-level problems
> for every specific domain, it will become an unimplementable mess.
> RDF already made a similar mistake by mixing together a spec for
> object encoding in XML with a spec for representing knowledge about
> Web pages.
>
>
> All the best,
>
>
> David
>
> --
> David Megginson david@megginson.com
> http://www.megginson.com/
>
> xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev@ic.ac.uk
> Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/ and on
CD-ROM/ISBN 981-02-3594-1
> To unsubscribe, mailto:majordomo@ic.ac.uk the following message;
> unsubscribe xml-dev
> To subscribe to the digests, mailto:majordomo@ic.ac.uk the following
message;
> subscribe xml-dev-digest
> List coordinator, Henry Rzepa (mailto:rzepa@ic.ac.uk)
>
>
xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev@ic.ac.uk
Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/ and on CD-ROM/ISBN 981-02-3594-1
To unsubscribe, mailto:majordomo@ic.ac.uk the following message;
unsubscribe xml-dev
To subscribe to the digests, mailto:majordomo@ic.ac.uk the following message;
subscribe xml-dev-digest
List coordinator, Henry Rzepa (mailto:rzepa@ic.ac.uk)
|