This text file contains sample code fragments from:
Section 22.5 - Loose Schema Versioning (Using Wildcards)
Chapter 22 - Versioning Message Schemas
Book - Web Service Contract Design & Versioning for SOA
Series - The Prentice Hall Service Technology Series from Thomas Erl
Site - www.servicetechbooks.com


<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  targetNamespace="http://actioncon.com/schema/po"
  xmlns="http://actioncon.com/schema/po"
  elementFormDefault="qualified"
  version="1.0">
  <xsd:element name="LineItem" type="LineItemType"/>
  <xsd:complexType name="LineItemType">
    <xsd:sequence>
      <xsd:element name="productID" type="xsd:string"/>
      <xsd:element name="productName" type="xsd:string"/>
      <xsd:any namespace="##any" processContents="lax"
        minOccurs="0" maxOccurs="unbounded"/>
    </xsd:sequence>
    <xsd:anyAttribute namespace="##any"/>
  </xsd:complexType>
</xsd:schema>

Example 22.25 - The base schema is extended with xsd:any and xsd:anyAttribute wildcards. Our assumption is that we designed these extensions into version 1.0 of our base schema in support of future Loose versioning.


<LineItem xmlns="http://actioncon.com/schema/po">
  <productID>AY2345</productID>
  <productName>Service Blaster 2000</productName>
</LineItem>

Example 22.26 - A basic XML document instance that conforms to the original element declarations.


<LineItem xmlns="http://actioncon.com/schema/po">
  <productID>AY2345</productID>
  <productName>Service Blaster 2000</productName>
<available>true</available>
</LineItem>

Example 22.27 - An extended XML document instance that conforms to the schema because of its use of wildcards.


<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  targetNamespace="http://actioncon.com/schema/po"
  xmlns="http://actioncon.com/schema/po"
  version="1.1">
  <xsd:element name="LineItem" type="LineItemType"/>
  <xsd:complexType name="LineItemType">
    <xsd:sequence>
      <xsd:element name="productID" type="xsd:string"/>
      <xsd:element name="productName" type="xsd:string"/>
      <xsd:element name="extension" type="ExtensionType"
        minOccurs="0"/>
    </xsd:sequence>
  </xsd:complexType>
  <xsd:complexType name="ExtensionType">
    <xsd:sequence>
      <xsd:any namespace="##targetNamespace"
        processContents="lax" minOccurs="0"
        maxOccurs="unbounded"/>
    </xsd:sequence>
    <xsd:anyAttribute namespace="##any"/>
  </xsd:complexType>
</xsd:schema>

Example 22.28 - The xsd:any and xsd:anyAttribute wildcards wrapped in a separate extension element declaration.


<LineItem xmlns="http://actioncon.com/schema/po">
  <productID>AY2345</productID>
  <productName>Service Blaster 2000</productName>
  <extension>
    <available>true</available>
  </extension>
</LineItem>

Example 22.29 - A message instance containing the required extension wrapper element in order to conform to the preceding schema.


<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  targetNamespace="http://actioncon.com/schema/po"
  xmlns="http://actioncon.com/schema/po"
  version="1.1">
  <xsd:element name="LineItem" type="LineItemType"/>
  <xsd:complexType name="LineItemType">
    <xsd:sequence>
      <xsd:element name="productID" type="xsd:string"/>
      <xsd:element name="productName" type="xsd:string"/>
      <xsd:any namespace="##any" processContents="lax"
        minOccurs="0" maxOccurs="unbounded"/>
    </xsd:sequence>
    <xsd:anyAttribute namespace="##any"/>
  </xsd:complexType>
</xsd:schema>

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  targetNamespace="http://actioncon.com/schema/po2"
  xmlns:po2="http://actioncon.com/schema/po2"
  version="1.0">
  <xsd:element name="available" type="xsd:boolean"/>
</xsd:schema>

Example 22.30 - An XML schema in the same target namespace as the preceding schema, providing the element declaration for the available element.


<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  targetNamespace="http://actioncon.com/schema/po"
  xmlns="http://actioncon.com/schema/po"
  version="1.0">
  <xsd:element name="LineItem" type="LineItemType"/>
  <xsd:complexType name="LineItemType">
    <xsd:sequence>
      <xsd:element name="productID" type="xsd:string"
        minOccurs="0"/>
      <xsd:element name="productName" type="xsd:string"/>
      <xsd:any namespace="##any" processContents="lax"
        minOccurs="0" maxOccurs="unbounded"/>
    </xsd:sequence>
    <xsd:anyAttribute namespace="##other"/>
  </xsd:complexType>
</xsd:schema>

Example 22.31 - The productName element declaration has been identified as an XML Schema component that needs to be removed.


<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  targetNamespace="http://actioncon.com/schema/po"
  xmlns="http://actioncon.com/schema/po"
  version="1.1">
  <xsd:element name="LineItem" type="LineItemType"/>
  <xsd:complexType name="LineItemType">
    <xsd:sequence>
      <xsd:element name="productID" type="xsd:string"
        minOccurs="0"/>
      <!-- productName Removed 09/12 -->
      <xsd:any namespace="##any" processContents="lax"
        minOccurs="0" maxOccurs="unbounded"/>
    </xsd:sequence>
    <xsd:anyAttribute namespace="##other"/>
  </xsd:complexType>
</xsd:schema>

Example 22.32 - The LineItemType construct after the productName element declaration has been removed.


<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  targetNamespace="http://actioncon.com/schema/po"
  xmlns="http://actioncon.com/schema/po"
  version="1.0">
  <xsd:element name="LineItem" type="LineItemType"/>
  <xsd:complexType name="LineItemType">
    <xsd:sequence>
      <xsd:element name="productID" type="xsd:string"/>
      <xsd:element name="productName" type="xsd:string"/>
      <xsd:any namespace="##any" processContents="lax"
        minOccurs="0" maxOccurs="unbounded"/>
    </xsd:sequence>
    <xsd:anyAttribute namespace="##other"/>
  </xsd:complexType>
</xsd:schema>

Example 22.33 - The productID element declaration is identified as having to be removed from this schema.


<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  targetNamespace="http://actioncon.com/schema/po"
  xmlns="http://actioncon.com/schema/po"
  version="1.1">
  <xsd:element name="LineItem" type="LineItemType"/>
  <xsd:complexType name="LineItemType">
    <xsd:sequence>
      <xsd:element name="productID" type="xsd:anyType"
        minOccurs="0"/>
      <xsd:element name="productName" type="xsd:string"/>
      <xsd:any namespace="##any" processContents="lax"
        minOccurs="0" maxOccurs="unbounded"/>
    </xsd:sequence>
    <xsd:anyAttribute namespace="##other"/>
  </xsd:complexType>
</xsd:schema>

Example 22.34 - The value of the type attribute of the productID element is changed to "xsd:anyType."


<xsd:any namespace="##any" processContents="lax"
  minOccurs="0" maxOccurs="unbounded"/>


<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  targetNamespace="http://actioncon.com/schema/po"
  xmlns="http://actioncon.com/schema/po"
  version="1.1">
  <xsd:element name="LineItem" type="LineItemType"/>
  <xsd:complexType name="LineItemType">
    <xsd:sequence>
      <xsd:element name="productID" type="xsd:string"/>
      <xsd:element name="productName" type="xsd:string"/>
      <xsd:any namespace="##other" processContents="lax"
        minOccurs="0" maxOccurs="unbounded"/>
    </xsd:sequence>
    <xsd:anyAttribute namespace="##other"/>
  </xsd:complexType>
</xsd:schema>

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  targetNamespace="http://actioncon.com/schema/po"
  xmlns="http://actioncon.com/schema/po"
  version="1.0">
  <xsd:element name="available" type="xsd:boolean"/>
</xsd:schema>

Example 22.35 - The ##other attribute value used to require that elements belonging to the unknown set reside in a namespace other than the target namespace of the primary schema document. However, the second schema document is still using the same target namespace.


<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  targetNamespace="http://actioncon.com/schema/po/extension"
  xmlns="http://actioncon.com/schema/po/extension"
  version="1.0">
  <xsd:element name="available" type="xsd:boolean"/>
</xsd:schema>

Example 22.36 - The secondary schema has been corrected to use a new target namespace.


<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  targetNamespace="http://actioncon.com/schema/po"
  xmlns="http://actioncon.com/schema/po"
  version="1.1">
  <xsd:element name="LineItem" type="LineItemType"/>
  <xsd:complexType name="LineItemType">
    <xsd:sequence>
      <xsd:element name="productID" type="xsd:string"/>
      <xsd:element name="productName" type="xsd:string"/>
      <xsd:any namespace="##other" processContents="skip"
        minOccurs="0" maxOccurs="unbounded"/>
    </xsd:sequence>
    <xsd:anyAttribute namespace="##other"/>
  </xsd:complexType>
</xsd:schema>

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  targetNamespace="http://actioncon.com/schema/po"
  xmlns:po2="http://actioncon.com/schema/po2"
  version="1.0">
  <xsd:element name="available" type="xsd:boolean"/>
</xsd:schema>

Example 22.37 - The processContents attribute of the xsd:any wildcard declaration set to a value of "skip."