RE: [xml-dev] Schema validation question

[Tom Gaven <Tom.Gaven@exostar.com>]

Linda, just RELAX, and get some sleep.

schema:
start = Fruits
Fruits = element Fruits { Fruit+ }
Fruit  = element Fruit  { Apple | Orange  }
Apple  = element Name { 'Apple' }, element Abbrev { 'APL' }
Orange = element Name { 'Orange' }, element Abbrev { 'ORG' }

instance:
<Fruits>
   <Fruit>   
       <Name>Apple</Name>  
       <Abbrev>APL</Abbrev>  
   </Fruit>  
   <Fruit>  
      <Name>Orange</Name>   
      <Abbrev>ORG</Abbrev> 
    </Fruit> 
    
     <!-- invalid:
     <Fruit>  
       <Name>Apple</Name>  
       <Abbrev>ORG</Abbrev> 
     </Fruit>
     -->
</Fruits>



-----Original Message-----
From: Linda Grimaldi [mailto:grimlinda@earthlink.net] 
Sent: Tuesday, May 04, 2004 5:18 PM
To: xml-dev@lists.xml.org
Subject: [xml-dev] Schema validation question


I have been out of the XML world for a little while now, but someone just
asked me a question and I have to admit, it's going to keep me up tonight if
I can't come up with a better solution.  And I'm a little rusty, to boot...

The issue is one of data dependency and validation.  The goal is to enforce
a restriction on pairs of data values- if the data associated with the node
<Fruit><Name> is "Apple", then the value of the sibling node <Fruit><Abbrev>
must be "APL".  Effectively, the goal is to enforce a specific mapping from
one enum into another within an XML document. The only way my associate
could figure to capture this dependency is as follows:

<xs:complexType name="Fruit">
	<xs:annotation>
		<xs:documentation>Defines the valid values for fruit
types</xs:documentation>
	</xs:annotation>
	<xs:choice>
		<xs:element name="APL" type="xs:token" fixed="Apple"/>
		<xs:element name="ORG" type="xs:token" fixed="Orange"/>
		<xs:element name="BAN" type="xs:token" fixed="Banana"/>
		<xs:element name="LEM" type="xs:token" fixed="Lemon"/>
		<xs:element name="GRP" type="xs:token" fixed="Grape"/>
	</xs:choice>
</xs:complexType>

All in all, this strikes me as a very ugly, even offensive, solution.  My
initial response was to forget about the validation- it wasn't worth it.  Is
there a way to preserve the data dependency validation without warping the
instance document as the above schema fragment would require?

Thanks,
Linda

-----------------------------------------------------------------
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>