xsd choice for multiple elements

Pradeep Achar picture Pradeep Achar · Feb 26, 2013 · Viewed 40.4k times · Source

I would like my Xml file to look like the following

<root>
<name>a</name>
<age>23</age>
</root>

 or 

<root>
<empno>b<empno>
<designation>ase</designation>
</root>

is it possible to create a XML schema for the above using a "choice" indicator?something like below.

    <xsd:element name="root">
    <xsd:complexType>
    <xsd:choice>

    <xsd:element name="name"/>
    <xsd:element name="age" />

     or

    <xsd:element name="empno"/>
    <xsd:element name="designation" />

    <xsd:choice>

    </xsd:complexType>
    <xsd:element>

Is it possible to do like this?

Answer

InfantPro&#39;Aravind&#39; picture InfantPro'Aravind' · Feb 26, 2013

Yes, You are almost there.. just missing a sequence .. Since it's the set of fields you have to wrap them under sequence..

These sequence tags will be under <Choice> tag. Now either of these set of tags (Sequence) will be validated.

<?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" type="root"/>
  <xs:complexType name="root">
    <xs:choice>
      <xs:sequence>
        <xs:element name="empno" type="xs:string" />
        <xs:element name="designation" type="xs:string" />
      </xs:sequence>
      <xs:sequence>
        <xs:element name="name" type="xs:string" />
        <xs:element name="age" type="xs:unsignedByte" />
      </xs:sequence>
    </xs:choice>
  </xs:complexType>
</xs:schema>

-----------------------------------------------------------------------------------------

I would like to add one more suggestion here:

I observe that you use nested declarations .. like this:

<?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="trunk">
          <xs:complexType>
            <xs:sequence>
              <xs:element name="branch1" type="xs:string"/>
              <xs:element name="branch2" type="xs:string"/>
            </xs:sequence>
          </xs:complexType>
        </xs:element>
        <xs:element name="other" type="xs:string" />
      </xs:sequence>
    </xs:complexType>
  </xs:element>
</xs:schema>

Always prefer usage of Custom types! Like this:

<?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" type="root"/>

  <xs:complexType name="root">
    <xs:sequence>
      <xs:element name="trunk" type="trunk"/>
      <xs:element name="other" type="xs:string" />
    </xs:sequence>
  </xs:complexType>

  <xs:complexType name="trunk">
    <xs:sequence>
      <xs:element name="branch1" type="xs:string"/>
      <xs:element name="branch2" type="xs:string"/>
    </xs:sequence>
  </xs:complexType>
</xs:schema>

This improves readability and you can reuse the complexType/simpleType ..

hope it helps..