atom feed15 messages in org.xml.lists.xml-dev[schema] which assertions can't you e...
FromSent OnAttachments
Philippe PoulardSep 8, 2004 4:53 am 
Chiusano JosephSep 8, 2004 6:24 am 
Christian NentwichSep 8, 2004 6:35 am 
Cross, Neal - Senior DeveloperSep 8, 2004 6:36 am 
Chiusano JosephSep 8, 2004 6:39 am 
Cross, Neal - Senior DeveloperSep 8, 2004 6:47 am 
David CarlisleSep 8, 2004 6:57 am 
Philippe PoulardSep 8, 2004 6:58 am 
Philippe PoulardSep 8, 2004 7:10 am 
Cross, Neal - Senior DeveloperSep 8, 2004 7:14 am 
Cross, Neal - Senior DeveloperSep 8, 2004 7:23 am 
David CarlisleSep 8, 2004 7:45 am 
Owen WalcherSep 8, 2004 8:25 am 
David RR Webber (XML eBusiness)Sep 9, 2004 5:31 am 
Cross, Neal - Senior DeveloperSep 9, 2004 6:57 am 
Subject:[schema] which assertions can't you express ?
From:Philippe Poulard (Phil@sophia.inria.fr)
Date:Sep 8, 2004 4:53:45 am
List:org.xml.lists.xml-dev

hi,

An XML Schema is the expression of some assertions expected on an XML document class. Assertions on XML documents ensure that applications will process them without causing faults. Expressing assertions with schemas ensure that applications developpers will spend most of their time in designing data process and few of their time in controlling them.

Any schema technology is designed to cover numbers of assertions expressed. However, if think that the existing schema technologies (DTD, W3C XML Schema, Relax NG, Schematron) can't express some constraint types.

I have some ideas of what these constraint types might be, but I'd like to know, helped by your own experiences, which kind of useful assertions can't be expressed with these schema technologies (so frustrating).

For example : -i'd like that the number of occurrences of an element is equal to a value of a given attribute (Schematron could do that) -i'd like that the value of a given attribute exists in my RDBMS -etc...

Thanks in advance -- Cordialement,

/// (. .) -----ooO--(_)--Ooo----- | Philippe Poulard | -----------------------