Question

I try to define a schema for XML documents I receive.

The documents look like:

<root>     <items>         <group name='G-1'>             <item name='I-1'/>             <item name='I-2'/>             <item name='I-3'/>             <item name='I-4'/>         </group>     </items>     <data>         <group name='G-1' place='here'>             <customer name='C-1'>                 <item name='I-1' count='3'/>                 <item name='I-2' count='4'/>             </customer>             <customer name='C-2'>                 <item name='I-3' count='7'/>             </customer>         </group>     </data> </root> 

I tried XmlSpy and xsd.exe from .NET 2.0. Both created schema definitions which allow below <group> any number of <item> and <customer> elements. But what I’m looking for should restrict <group> below <items> to <item> elements, and <group> below <data> to <customer> elements.

Is this something xml schema is not capable at all?

Answer 1

Yes, XSD can handle this. I generated this schema from Visual Studio 2008 (much faster than doing it by hand) and it will do what you’re looking for:

<?xml version='1.0' encoding='utf-8'?> <xs:schema attributeFormDefault='unqualified' elementFormDefault='qualified' xmlns:xs='http://www.w3.org/2001/XMLSchema'>   <xs:element name='root'>     <xs:complexType>       <xs:sequence>         <xs:element name='items'>           <xs:complexType>             <xs:sequence>               <xs:element name='group'>                 <xs:complexType>                   <xs:sequence>                     <xs:element maxOccurs='unbounded' name='item'>                       <xs:complexType>                         <xs:attribute name='name' type='xs:string' use='required' />                       </xs:complexType>                     </xs:element>                   </xs:sequence>                   <xs:attribute name='name' type='xs:string' use='required' />                 </xs:complexType>               </xs:element>             </xs:sequence>           </xs:complexType>         </xs:element>         <xs:element name='data'>           <xs:complexType>             <xs:sequence>               <xs:element name='group'>                 <xs:complexType>                   <xs:sequence>                     <xs:element maxOccurs='unbounded' name='customer'>                       <xs:complexType>                         <xs:sequence>                           <xs:element maxOccurs='unbounded' name='item'>                             <xs:complexType>                               <xs:attribute name='name' type='xs:string' use='required' />                               <xs:attribute name='count' type='xs:unsignedByte' use='required' />                             </xs:complexType>                           </xs:element>                         </xs:sequence>                         <xs:attribute name='name' type='xs:string' use='optional' />                       </xs:complexType>                     </xs:element>                   </xs:sequence>                   <xs:attribute name='name' type='xs:string' use='required' />                   <xs:attribute name='place' type='xs:string' use='required' />                 </xs:complexType>               </xs:element>             </xs:sequence>           </xs:complexType>         </xs:element>       </xs:sequence>     </xs:complexType>   </xs:element> </xs:schema>