Re: XLink: the architectural issue

Goodness, what a thread.

+1 - this is an excellent characterisation of the problem. It resonates
with other principals that I've always considered part of the Web
architecture, even if they aren't in the draft (yet!) -

* Don't tell other people what to do in their name spaces
* Don't put metadata in identifiers

From-a-URI-opacity-perspective-ly-yours,


----- Original Message -----
From: "Eric van der Vlist" <vdv@dyomedea.com>
To: "Steven Pemberton" <steven.pemberton@cwi.nl>
Cc: <www-tag@w3.org>; "HTML WG" <w3c-html-wg@w3.org>
Sent: Thursday, September 26, 2002 11:59 PM
Subject: Re: XLink: the architectural issue


>
> On Fri, 2002-09-27 at 01:34, Steven Pemberton wrote:
>
> <good_and_simple_stuff_sniped/>
>
> > However, if some specification, say XDates, appropriates all
attributes of
> > type Date, then you can't just do this, you have to look to see what
other
> > attributes are already in use. So instead of
> >
> >     <para abc:created="2001-01-01" xyz:edited="2002-09-26">
> >         Now is the time
> >     </para>
> >
> > I would have to say
> >
> >     <para>
> >         <created xdate:date="2001-01-01"/>
> >         <edited xdate:date="2002-09-26"/>
> >         Now is the time.
> >     </para>
>
> That's a great way to present the problem and show it as a consequence
> of the lack of extensibility of XML attributes.
>
> I'd like to make a (probably silly) proposal for a novel usage of
> namespaces. Of course, it wouldn't apply to XLink which is already baked
> and a generic schema for the xdate namespace wouldn't be possible to
> express with W3C XML Schema (too bad, you'd have to use Relax NG :-) )
> but if we said that the xdate namespace is identifying dates and that
> "host vocabularies" may choose any local name in this namespace to
> express their dates, we could write:
>
> <para xdate:created="2001-01-01" xdate:edited="2002-09-26">
> Now is the time
> </para>
>
> The xdate namespace would identify the nature of the attribute and its
> local name would identify its purpose as defined by the host vocabulary.
> It's probably not ideal, but when we play with attributes, we don't have
> that much variables we can play with!
>
> The other (quite ugly IMO) solution would be through the PSVI (don't
> care what the local name and namespace of the attribute are but its type
> must be xdate:date) but it would make the usage of W3C XML Schema
> mandatory and I see HLink as a lightweight alternative to achieve the
> same kind of functionality.
>
> Eric
> --
> Rendez-vous à Paris.
>                           http://www.technoforum.fr/integ2002/index.html
> ------------------------------------------------------------------------
> Eric van der Vlist       http://xmlfr.org            http://dyomedea.com
> (W3C) XML Schema ISBN:0-596-00252-1 http://oreilly.com/catalog/xmlschema
> ------------------------------------------------------------------------
>

Received on Wednesday, 2 October 2002 17:04:45 UTC