RE: Elements order:

["Christopher R. Maden" <crism@maden.org>]

At 02:46 23-08-2001, Nicolas LEHUEN wrote:
>What if we add an <age> element now ? Then a <gender> element ? The content
>model will explode. You need something like the <all> content model of XSDL.
>I've heard that there is a way to express this in SGML DTDs, but it has been
>dropped in XML, is that true ?

Yes.  SGML had an "and" connector:

<!ELEMENT data - - (name & surname & age & gender)>

would require exactly one each of name, surname, age, and gender, in any order.

However, there were concerns that the way SGML mandated the interpretation 
of this content model was not easily implemented.  This capability, without 
SGML's restrictions, is back in Schemas.

>This is all the more annoying that for structured data, it does not matter
>that the <name> element precedes the <surname> or not.

I disagree there - I like to be able to encode Asian and western names in 
their proper cultural order but still know which is the given and which is 
the family name.

-Chris
-- 
Christopher R. Maden, XML Consultant
DTDs/schemas - conversion - ebooks - publishing - Web - B2B - training
<URL: http://crism.maden.org/consulting/ >
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