OASIS Mailing List ArchivesView the OASIS mailing list archive below
or browse/search using MarkMail.


Help: OASIS Mailing Lists Help | MarkMail Help



   RE: [xml-dev] Restrictions on existence of attributes?

[ Lists Home | Date Index | Thread Index ]

Perhaps a reference to an attribute group, with a minOccurs and maxOccurs of 1? 


Joseph Chiusano
Booz Allen Hamilton
700 13th St. NW, Suite 1100
Washington, DC 20005
O: 202-508-6514  
C: 202-251-0731
Visit us online@ http://www.boozallen.com

-----Original Message-----
From: Robin Berjon [mailto:robin.berjon@expway.fr] 
Sent: Tuesday, June 27, 2006 6:59 AM
To: Rick Jelliffe
Cc: Howard Bartel; xml-dev@lists.xml.org Developers
Subject: Re: [xml-dev] Restrictions on existence of attributes?

> Howard Bartel wrote:
>> On Jun 27, 2006, at 07:57, Rick Jelliffe wrote:
>> How do I specify that an element MUST have ONLY ONE of a set of 
>> possible attributes?
>> I understand that there is a "choice" option but it seems that this 
>> only applies to elements, not attributes within an element.
> If you are using XML Schemas, then look at the "enumeration"  
> "facet" of "datatypes". Your element must be a "complex type".

I don't think that'll solve Howard's problem since he wants only one of a set of attributes, not only one of a set of attribute values.  
Presumably this can always be remodelled with some indirection (e.g.  
having a @name attribute which is an enumeration, and an @value which would give its value), but that might not be an option.

My XML Schema is getting very rusty since I don't get to use it much anymore, but I don't think it can be done (or if it can it involves dark magic). In RelaxNG it's just a <choice> of <attribute> elements, easy as &pgr;.

Robin Berjon
    Senior Research Scientist
    Expway, http://expway.com/

The xml-dev list is sponsored by XML.org <http://www.xml.org>, an
initiative of OASIS <http://www.oasis-open.org>

The list archives are at http://lists.xml.org/archives/xml-dev/

To subscribe or unsubscribe from this list use the subscription
manager: <http://www.oasis-open.org/mlmanage/index.php>


News | XML in Industry | Calendar | XML Registry
Marketplace | Resources | MyXML.org | Sponsors | Privacy Statement

Copyright 2001 XML.org. This site is hosted by OASIS