Question

I am writing a schema for XML documents like this:

<workbook>
  <worksheet>
    <column/>
  </worksheet>
</workbook>

Where each node can be wrapped into the env element (e.g.)

<workbook>
 <env>
  <worksheet>
   <column/>
  </worksheet>
 </env>
</workbook>

or

<workbook>
 <worksheet>
  <env>
   <column/>
  </env>  
 </worksheet>
</workbook>

So, depending on the location of the env element, it can have different children (env-child of workbook must have worksheet children and env-child of worksheet must have column children)

When I am declaring env elements as nested, I get multiply-defined element errors.

How could I write xsd for such document, or is it at all possible?

Thanks in advance!

Answer 1

Yes, it is possible, because you can have elements with the same name env but with different types (structure) in different places – something linke this:

<xs:element name="workbook">
  <xs:complexType>
    <xs:choice>
      <xs:element name="env">
        <xs:complexType>
          <xs:sequence>
            <xs:element ref="worksheet"/>
          </xs:sequence>
        </xs:complexType>
      </xs:element>
      <xs:element ref="worksheet"/>
    </xs:choice>
  </xs:complexType>
</xs:element>

<xs:element name="worksheet">
  <xs:complexType>
    <xs:choice>
      <xs:element name="env">
        <xs:complexType>
          <xs:sequence>
            <xs:element ref="column"/>
          </xs:sequence>
        </xs:complexType>
      </xs:element>
      <xs:element ref="column"/>
    </xs:choice>
  </xs:complexType>
</xs:element>

<xs:element name="column" type="xs:string">
</xs:element>