----- Original Message -----
Sent: Friday, August 16, 2002 11:40
AM
Subject: RE: [xml-dev] XML-Schema
Help
I believe this will not work because the schema would be
non-determinstic. That is, because the following declaration:
<xs:element
ref="earliestdate" minOccurs="0"/>
appears in two different "choice" constructs, a schema
processor will not be able to discern whether an occurrence of "earliestdate"
is applicable to the first "choice" construct or the second one. Same
idea for "latestdate".
Regards,
Joe Chiusano
LMI
>
**************************************************************************
> Joseph M. Chiusano
> Logistics Management Institute
> 2000 Corporate Ridge
> McLean, VA 22102
> Email: jchiusano@lmi.org
> Tel: 571.633.7722
>
**************************************************************************
>
-----Original Message-----
From: Bryce
K. Nielsen [mailto:bryce@sysonyx.com]
Sent: Friday, August 16, 2002 1:30 PM
To:
xml-dev@lists.xml.org
Subject: Re: [xml-dev]
XML-Schema Help
> My question is this, in a Schema is it possible to have
an element be
> required only if its parent element
exists.
>
> For example
in the code below if timeframetype exists then either
> earliestdate or latestdate would be required, 1 or the other but
both are
> not required.
>
> <xs:complexType
name="timeframeType">
>
<xs:sequence>
> <xs:element
ref="description"/>
> <xs:element
ref="earliestdate" minOccurs="0"/>
>
<xs:element ref="latestdate" minOccurs="0"/>
> </xs:sequence>
>
</xs:complexType>
>
There are a lot of different ways you could do this, but
here's a go:
<xs:complexType name="timeframeType">
<xs:sequence>
<xs:element ref="description"/>
<xs:choice>
<xs:element ref="earliestdate"
minOccurs="0"/>
<xs:element ref="latestdate" minOccurs="0"/>
</xs:choice>
<xs:choice>
<xs:element ref="earliestdate"
minOccurs="0"/>
</xs:choice>
<xs:choice>
<xs:element ref="latestdate"
minOccurs="0"/>
</xs:choice>
</xs:sequence>
</xs:complexType>
you could refactor this into groups for easier
reading...
-BKN
-----------------------------------------------------------------
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://lists.xml.org/ob/adm.pl>
