Re: Validating one XML value against another

spinout · August 27th, 2008, 02:30 AM

Hello,

I'm wondering if it's possible to validate 1 XML value against another?

For example, I have a list of genres and sub-genres in an XML feed and based on the specified genre in the XML I want to validate it against a list of allowable sub-genre values for that genre.

Code:

<myfeed genre="fruit" subgenre="apples" />
<myfeed genre="animals" subgenre="tiger" />

I want the schema to first see the genre of "fruit" or "animals" and based on which one was selected validate it against different xsd:enumeration blocks.

So, if fruit was selected as the genre, a list of allowable sub-genres would be...

Code:

<xsd:restriction base="xsd:string">
  <xsd:enumeration value="apples" />
  <xsd:enumeration value="oranges" />
  <xsd:enumeration value="bananas" />
</xsd:restriction>

And if animals was selected as the genre, a list of allowable sub-genres would be...

Code:

<xsd:restriction base="xsd:string">
  <xsd:enumeration value="tiger" />
  <xsd:enumeration value="monkey" />
  <xsd:enumeration value="panda" />
</xsd:restriction>

mhkay · August 27th, 2008, 03:24 AM

You can do this with "conditional type assignment" in XML Schema 1.1 (the <xs:alternative> element). It's not widely implemented yet, but you can try it out in Saxon-SA 9.1. Something like this:

<xs:element name="myfeed" type="feedType">
  <xs:alternative test="@genre='string'" type="fruitType"/>
  <xs:alternative test="@genre='animals'" type="animalType"/>
</xs:element>

<xs:complexType name="feedType">
    <xs:sequence/>
    <xs:attribute name="genre" type="..."/>
</xs:complexType>

<xs:complexType name="fruitType">
  <xs:complexContent>
   <xs:extension base="feedType">
     .... etc

Michael Kay
http://www.saxonica.com/
Author, XSLT 2.0 and XPath 2.0 Programmer's Reference

spinout · August 27th, 2008, 09:05 AM

Quote:

quote:Originally posted by mhkay
You can do this with "conditional type assignment" in XML Schema 1.1 (the <xs:alternative> element). It's not widely implemented yet, but you can try it out in Saxon-SA 9.1. Something like this:

Thanks mhkay. I tried out your suggestion, but Visual Studio didn't want to know about it.

Does anyone know of a way to achieve this in XML Schema 1.0??

mhkay · August 27th, 2008, 01:35 PM

It can't be done in XML Schema 1.0.

Michael Kay
http://www.saxonica.com/
Author, XSLT 2.0 and XPath 2.0 Programmer's Reference