xml-dev - Re: Should we care about elements order ?

[Robin LaFontaine <robin@monsell.co.uk>]

Eric,

I agree that it is worrying that XML Schema does not allow 'order 
significance' to be specified for a given element.

For use of XML with data (as opposed to documents), we need *both* 
elements that are ordered and those that are not.

For example, a list of co-ordinate points representing a polygon is 
definitely ordered. But a set a co-ordinates representing valid 
positions is not ordered.

In XML Schema itself (i.e. XML Schema for XML Schema), order of 
elements in a choice is not order-significant, but the order of 
elements in a sequence is order-significant!

I conclude that it is a great shame that XML Schema does not allow us 
to indicate for an element whether or not its content is 
order-significant.

Robin

At 11:07 am +0200 21/10/00, Eric van der Vlist wrote:
>To summarize what has been told so far:
>
>...cut
>I am quite comfortable with these conclusions which are kind of
>confirming what I thought, but still disappointed that it invalidates
>the usage of XML Schema, a specification which given the weight of the
>W3C is likely to play a major role in the future.
>
>The usage of Schematron is still an interesting option, of course.
>
>Another one could be a specific validation package composed of a XSLT
>transformation "normalizing" the document followed by a XML Schema (or
>DTD or Relax) validation.
>
>Such a mechanism could even be used for DTD validation of multi
>namespaces documents.
>
>It's likely to be far more complex to deploy than a single pass standard
>validation process, though.
>
>Thanks for your answers !
>
>Eric
>
>------------------------------------------------------------------------
>Eric van der Vlist       Dyomedea                    http://dyomedea.com
>http://xmlfr.org         http://4xt.org              http://ducotede.com
>------------------------------------------------------------------------

-- -----------------------------------------------------------------
Robin La Fontaine, Monsell EDM Ltd
(Engineering data exchange and management using XML, R&D Project Management)
Tel: +44 1684 592 144 Fax: +44 1684 594 504
Email: robin@monsell.co.uk       http://www.monsell.co.uk