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Re: In lieu of multiple attlists: LINK?



At 14:27 24.02.97 +0100, Martin Bryan wrote:
>At 12:43 21/2/97 +0100, Steve Pepper wrote:
>
>>It seems to me that this is PRECISELY the kind of use for which LINK was
>>originally intended: the association of processing with structure in a
>>modular and eXtensible way. It provides the perfect, SGML-compliant way
>>of making existing documents XML-processable without having to modify
>>the DTD or document, and without having to invent new syntax.
>
>...
>
>The question is, which of the XML link attributes are fixed and which of
>them must be user variable. So far all the examples have only shown the one
>fixable attribute, that showing the XML link type. But does this work with
>variable ones, such as locator and caption? Unfortunately I don't see how a
>strictly SGML-confornant link-based solution can deal with these.

I think we are talking about different things here.

The LINK-based syntax that I am proposing is intended to tell an XML
processor something useful about an existing document without having to
edit either the document or the DTD. It's just a way to let (say) the TEI
DTD say: "Hello, I'm the TEI DTD. You don't know me, but I have an xref
element type which I'd like you to treat as if it were xml-link."

Communicating this information can be accomplished without invalidating
the document with respect to SGML, using the syntax I propose.

You are talking about a scenario in which a user may want to specify
different attribute values on different instances of an element type--
which obviously requires editing the document. Trouble is, as soon as you
do that--and specify a value for an attribute which is "declared" using
a magic PI--you no longer have an SGML compatible document.

In short: The magic PI solution (<?xml attlist ... ?>) doesn't give you any
extra mileage. It's just yet more new syntax for something that already
exists.

Steve

--
Steve Pepper, SGML Architect, <pepper@falch.no>
Falch Infotek a.s, Postboks 130 Kalbakken, N-0902 Oslo, Norway
http://www.falch.no/  tel://+47 2290 2733  fax://+47 2290 2599
"Whirlwind Guide": http://www.falch.no/people/pepper/sgmltool/