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RE: Current status of XLink

• To: xml-dev@l...
• Subject: RE: Current status of XLink
• From: Eric van der Vlist <vdv@d...>
• Date: Fri, 26 Mar 2004 14:54:30 +0100
• In-reply-to: <20040326133602.NKPB325.mta07-svc.ntlworld.com@Turtle>
• Organization: Dyomedea (http://dyomedea.com)
• References: <20040326133602.NKPB325.mta07-svc.ntlworld.com@Turtle>

Hi Michael,

On Fri, 2004-03-26 at 14:35, Michael Kay wrote:
 
> In my view the mess is because XLink simply doesn't fit into the
> layering of the XML architecture. The whole point of XML is that you
> can choose any names you like for your objects and attributes, and
> give them any semantics that you like (typically captured in schemas
> and stylesheets). 

OTH, XML markup has the implicit semantic of describing tree structures
while we all know that if it's convenient for many tasks, that's not
enough to describe the outside world. 

> So why should relationships be different from objects and attributes,
> and require fixed names and fixed semantics? 

Because one may consider that a markup that would have some support for
describing graphs might be more useful than one that only supports
trees...
 
> Hyperlinking is something that belongs in the user interface layer,
> not in the stored information. The stored information needs to hold
> relationship information in a much more abstract form. The hyperlinks,
> like all other user interface objects, should be generated by the
> stylesheet. It's because the hyperlinking community failed to
> recognize this that the idea failed to catch on. The other consequence
> of this is that there is a gaping hole in the XML story as to how
> abstract relationships should be modelled.

I have mixed feeling about this statement :) .

In theory, I agree that "out of band" hyperlinking (ala RDF, Topic Maps
or extended XLinks) is way superior to "in band" hyperlinking (ala
a/@href).

OTH, hyperlink systems were limited to niche markets before HTML
introduced its own very imperfect "in band" hyperlinking which is one of
the main reasons for the success of the Web (and maybe also for the its
mess).

Who knows if something really basic such as reserved xml:id and xml:href
attributes wouldn't have been a big (and messy) success?

Eric
-- 
See you in Amsterdam.
                                               http://www.xmleurope.com/
Upcoming XML schema languages tutorial:
 - Amsterdam   -half day- (18/04/2004)        http://masl.to/?P220516D7
------------------------------------------------------------------------
Eric van der Vlist       http://xmlfr.org            http://dyomedea.com
(ISO) RELAX NG   ISBN:0-596-00421-4 http://oreilly.com/catalog/relax
(W3C) XML Schema ISBN:0-596-00252-1 http://oreilly.com/catalog/xmlschema
------------------------------------------------------------------------

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  • Re: Current status of XLink
    • From: Robin Berjon <robin.berjon@e...>

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  • RE: Current status of XLink
    • From: "Michael Kay" <michael.h.kay@n...>

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