Hi,

This is called co-occurrence constraint and it is not supported by the 
(current version of) XML Schema. You need to define a more relaxed 
schema and place the constraints at some other level, at application 
level for instance or using Schematron embedded rules. Below you can 
find a sample XML Schema with Schematron embedded rules:

<?xml version="1.0"?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">
     <xsd:element name=" Product">
         <xsd:annotation>
             <xsd:appinfo>
                 <pattern xmlns="http://www.ascc.net/xml/schematron" 
name="">
                     <rule context="Product[@pr_name='ONE']">
                         <assert test="@pr_Info='A' or @pr_Info='B'">For 
product ONE pr_Info should be A or B.</assert>
                     </rule>
                     <rule context="Product[@pr_name='TWO']">
                         <assert test="@pr_Info='C' or @pr_Info='D'">For 
product TWO pr_Info should be C or D.</assert>
                     </rule>
                 </pattern>
             </xsd:appinfo>
         </xsd:annotation>
         <xsd:complexType>
             <xsd:attribute name="pr_name">
                 <xsd:simpleType>
                     <xsd:restriction base="xsd:string">
                         <xsd:enumeration value="ONE"/>
                         <xsd:enumeration value="TWO"/>
                     </xsd:restriction>
                 </xsd:simpleType>
             </xsd:attribute>
             <xsd:attribute name="pr_Info">
                 <xsd:simpleType>
                     <xsd:restriction base="xsd:string">
                         <xsd:enumeration value="A"/>
                         <xsd:enumeration value="B"/>
                         <xsd:enumeration value="C"/>
                         <xsd:enumeration value="D"/>
                     </xsd:restriction>
                 </xsd:simpleType>
             </xsd:attribute>
         </xsd:complexType>
     </xsd:element>
</xsd:schema>

Best Regards,
George
---------------------------------------------------------------------
George Cristian Bina
<oXygen/> XML Editor, Schema Editor and XSLT Editor/Debugger
www.---.com

lawrence.michel@p... wrote:
> Hi all,
> 
> I'm actually trying to design an XML-Schema that should be universally
> used within form creation (Xforms, XSL-t processing, and XML validation
> check). I'm actually designing one that should be representing a graph
> of all possible valid attribute combination within an element. Below a
> simple example:
> 
> Here a basic Product element in XML:
> 
> <Product pr_name="ONE" pr_Info="A"/>
> 
> Now, according to some business rules, let's say that all products named
> "ONE" should have their pr_Info attribute set to either A or B, and all
> products named "TWO" should have their pr_Info attribute set to either C
> or D.
> 
> A possible solution is to design an XML-schema proposing a choice of all
> Product element representing all possible combination according to their
> pr_Name.
> 
> I'm looking to have to design it with the use of attribute groups, such
> as (pseudo-code below):
> 
> attributeGroupA is:
> 	Attribute name="pr_Info" value=restriction on either A or B
> attributeGroupB is:
> 	Attribute name="pr_Info" value=restriction on either C or D
> 
> Element product
> 	start choice
> 		choice 1: attribute pr_Name = ONE and attributeGroupA
> 		choice 2: attribute pr_Name = TWO and attributeGroupB
> 	end choice
> /Element
> 
> Which will correspond to validate XML data such as:
> 
> <Product pr_name="ONE" pr_Info="A"/>
> <Product pr_name="TWO" pr_Info="C"/>
> <Product pr_name="ONE" pr_Info="B"/>
> (...)
> 
> Any idea would be greatful
> 
> Best regards ;-)
> 
> Lawrence Michel
> 
> 

From sandra.martinez@n... Mon Aug 07 23:39:35 2006
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