[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message]

Re: XML-Schema Help

• To: "Dave Yancey" <dyancey1@h...>
• Subject: Re: XML-Schema Help
• From: ht@c... (Henry S. Thompson)
• Date: 19 Aug 2002 17:09:36 +0100
• Cc: xml-dev@l...
• In-reply-to: <F105XulRzbQPyJGSS2t00010016@h...>
• References: <F105XulRzbQPyJGSS2t00010016@h...>
• User-agent: Gnus/5.0808 (Gnus v5.8.8) XEmacs/21.2(beta13) (Demeter)

"Dave Yancey" <dyancey1@h...> writes:

> Hello all,
> 
> I've been following the threads here for a while and have learned a
> great deal from everyone.
> 
> 
> 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.
> 
> 
> Thanks for any help in advance.
> 
> David Yancey
> david_yancey@h...
> 
> 
> <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>

Sure -- for compactness, I'll use DTD notation:

<!ELEMENT eltWithTypeTimeframeType
          (description,((earliestDate,latestDate?)|latestDate))>

Turn that into xs:sequence and xs:choice and you've got what you need.

ht
-- 
  Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh
          W3C Fellow 1999--2002, part-time member of W3C Team
     2 Buccleuch Place, Edinburgh EH8 9LW, SCOTLAND -- (44) 131 650-4440
	    Fax: (44) 131 650-4587, e-mail: ht@c...
		     URL: http://www.ltg.ed.ac.uk/~ht/
 [mail really from me _always_ has this .sig -- mail without it is forged spam]

• References:
  • XML-Schema Help
    • From: "Dave Yancey" <dyancey1@h...>

• Prev by Date: Re: patterns vs. identifiers
• Next by Date: Re: patterns vs. identifiers
• Previous by thread: Re: XML-Schema Help
• Next by thread: RE: XMLHTTP Posts and performance
• Index(es):
  • Date
  • Thread