Definitive XML Schema
Priscilla Walmsley (pwalmsley@datypic.com)2nd edition (September 2012)
Prentice Hall PTR; ISBN: 0132886723
Chapter 13: Deriving complex types
Full Example
This example illustrates complex types that are derived from other specified types.
Instance (chapter13.xml)
<items xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="chapter14.xsd">
<hat routingNum="123456" effDate="2002-04-02" lang="en-US">
<number>557</number>
<name>Ten-Gallon Hat</name>
<description>This is a great hat!</description>
</hat>
<umbrella routingNum="123" effDate="2002-04-02">
<number>557</number>
<name>Ten-Gallon Hat</name>
</umbrella>
<shirt routingNum="124" effDate="2002-04-02" sleeve="17">
<number>557</number>
<name>Short-Sleeved Linen Blouse</name>
<color value="blue"/>
<size system="US-DRESS">6</size>
</shirt>
</items>
Schema (chapter13.xsd)
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="items" type="ItemsType"/>
<xs:complexType name="ItemsType">
<xs:choice minOccurs="0" maxOccurs="unbounded">
<xs:element name="hat" type="ProductType"/>
<xs:element name="umbrella" type="RestrictedProductType"/>
<xs:element name="shirt" type="ShirtType"/>
</xs:choice>
</xs:complexType>
<!--Empty Content Type-->
<xs:complexType name="ItemType" abstract="true">
<xs:attribute name="routingNum" type="xs:integer"/>
</xs:complexType>
<!--Empty Content Extension (with Attribute Extension)-->
<xs:complexType name="ProductType">
<xs:complexContent>
<xs:extension base="ItemType">
<xs:sequence>
<xs:element name="number" type="xs:integer"/>
<xs:element name="name" type="xs:string"/>
<xs:element name="description"
type="xs:string" minOccurs="0"/>
</xs:sequence>
<xs:attribute name="effDate" type="xs:date"/>
<xs:attribute name="lang" type="xs:language"/>
</xs:extension>
</xs:complexContent>
</xs:complexType>
<!--Complex Content Restriction-->
<xs:complexType name="RestrictedProductType">
<xs:complexContent>
<xs:restriction base="ProductType">
<xs:sequence>
<xs:element name="number" type="xs:integer"/>
<xs:element name="name" type="xs:token"/>
</xs:sequence>
<xs:attribute name="routingNum"
type="xs:short" use="required"/>
<xs:attribute name="effDate"
type="xs:date" default="1900-01-01"/>
<xs:attribute name="lang" use="prohibited"/>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
<!--Complex Content Extension-->
<xs:complexType name="ShirtType">
<xs:complexContent>
<xs:extension base="RestrictedProductType">
<xs:choice maxOccurs="unbounded">
<xs:element name="size" type="SmallSizeType"/>
<xs:element name="color" type="ColorType"/>
</xs:choice>
<xs:attribute name="sleeve" type="xs:integer"/>
</xs:extension>
</xs:complexContent>
</xs:complexType>
<!--Simple Content Extension-->
<xs:complexType name="SizeType">
<xs:simpleContent>
<xs:extension base="xs:integer">
<xs:attribute name="system" type="xs:token"/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
<!--Simple Content Restriction-->
<xs:complexType name="SmallSizeType">
<xs:simpleContent>
<xs:restriction base="SizeType">
<xs:minInclusive value="2"/>
<xs:maxInclusive value="6"/>
<xs:attribute name="system" type="xs:token"
use="required"/>
</xs:restriction>
</xs:simpleContent>
</xs:complexType>
<xs:complexType name="ColorType">
<xs:attribute name="value" type="xs:string"/>
</xs:complexType>
</xs:schema>
Book Examples
Example 13-1. Simple content extension
Schema:
<xs:complexType name="SizeType">
<xs:simpleContent>
<xs:extension base="xs:integer">
<xs:attribute name="system" type="xs:token"/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
Instance:
<size system="US-DRESS">10</size>
Example 13-2. Complex content extension
<xs:complexType name="ProductType">
<xs:sequence>
<xs:element name="number" type="xs:integer"/>
<xs:element name="name" type="xs:string"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="ShirtType">
<xs:complexContent>
<xs:extension base="ProductType">
<xs:choice maxOccurs="unbounded">
<xs:element name="size" type="xs:integer"/>
<xs:element name="color" type="xs:string"/>
</xs:choice>
</xs:extension>
</xs:complexContent>
</xs:complexType>
Example 13-3. Effective content model of ShirtType
<xs:complexType name="ShirtType">
<xs:sequence>
<xs:sequence>
<xs:element name="number" type="xs:integer"/>
<xs:element name="name" type="xs:string"/>
</xs:sequence>
<xs:choice maxOccurs="unbounded">
<xs:element name="size" type="xs:integer"/>
<xs:element name="color" type="xs:string"/>
</xs:choice>
</xs:sequence>
</xs:complexType>
Example 13-4.
choice group extension
<xs:complexType name="ItemsType">
<xs:choice maxOccurs="unbounded">
<xs:element ref="shirt"/>
<xs:element ref="hat"/>
<xs:element ref="umbrella"/>
</xs:choice>
</xs:complexType>
<xs:complexType name="ExpandedItemsType">
<xs:complexContent>
<xs:extension base="ItemsType">
<xs:choice maxOccurs="unbounded">
<xs:element ref="sweater"/>
<xs:element ref="suit"/>
</xs:choice>
</xs:extension>
</xs:complexContent>
</xs:complexType>
Example 13-5.
all group extension
<xs:complexType name="ProductType">
<xs:all>
<xs:element name="number" type="xs:integer"/>
<xs:element name="name" type="xs:string"/>
</xs:all>
</xs:complexType>
<xs:complexType name="ShirtType">
<xs:complexContent>
<xs:extension base="ProductType">
<xs:all>
<xs:element name="size" type="xs:integer"/>
<xs:element name="color" type="xs:string"/>
</xs:all>
</xs:extension>
</xs:complexContent>
</xs:complexType>
Example 13-6. Effective content model of ShirtType with all groups combined
<xs:complexType name="ShirtType">
<xs:all>
<xs:element name="number" type="xs:integer"/>
<xs:element name="name" type="xs:string"/>
<xs:element name="size" type="xs:integer"/>
<xs:element name="color" type="xs:string"/>
</xs:all>
</xs:complexType>
Example 13-7. Extending open content
<xs:complexType name="ProductType">
<xs:openContent mode="suffix">
<xs:any namespace="##other" processContents="lax"/>
</xs:openContent>
<xs:sequence>
<xs:element name="number" type="xs:integer"/>
<xs:element name="name" type="xs:string"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="ShirtType">
<xs:complexContent>
<xs:extension base="ProductType">
<xs:openContent mode="suffix">
<xs:any namespace="##any" processContents="lax"/>
</xs:openContent>
<xs:sequence>
<xs:element name="size" type="xs:integer"/>
<xs:element name="color" type="xs:string"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
Example 13-8. Mixed content extension
<xs:complexType name="LetterType" mixed="true">
<xs:sequence>
<xs:element name="custName" type="xs:string"/>
<xs:element name="prodName" type="xs:string"/>
<xs:element name="prodSize" type="xs:integer"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="ExtendedLetterType" mixed="true">
<xs:complexContent>
<xs:extension base="LetterType">
<xs:sequence>
<xs:element name="prodNum" type="xs:string"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
Example 13-9. Empty content extension
<xs:complexType name="ItemType"> <xs:attribute name="routingNum" type="xs:integer"/> </xs:complexType>
Example 13-10. Attribute extension
Schema:
<xs:complexType name="ItemType"> <xs:attribute name="id" type="xs:ID" use="required"/> <xs:attribute ref="xml:lang"/> </xs:complexType>
Example 13-11. Attribute wildcard extension
<xs:complexType name="BaseType">
<xs:anyAttribute processContents="lax"
namespace="##local
http://datypic.com/prod"/>
</xs:complexType>
<xs:complexType name="DerivedType">
<xs:complexContent>
<xs:extension base="BaseType">
<xs:anyAttribute processContents="strict"
namespace="##targetNamespace
http://www.w3.org/1999/xhtml"/>
</xs:extension>
</xs:complexContent>
</xs:complexType>
Example 13-12. Effective attribute wildcard
<xs:complexType name="DerivedType">
<xs:anyAttribute processContents="strict"
namespace="##local
http://datypic.com/prod
##targetNamespace
http://www.w3.org/1999/xhtml"/>
</xs:complexType>
Example 13-13. Simple content restriction
<xs:complexType name="SmallSizeType">
<xs:simpleContent>
<xs:restriction base="SizeType">
<xs:minInclusive value="2"/>
<xs:maxInclusive value="6"/>
<xs:attribute name="system" type="xs:token"
use="required"/>
</xs:restriction>
</xs:simpleContent>
</xs:complexType>
Example 13-14. Complex content restriction
<xs:complexType name="ProductType">
<xs:sequence>
<xs:element name="number" type="xs:integer"/>
<xs:element name="name" type="xs:string"/>
<xs:element name="size" type="xs:integer" minOccurs="0"/>
<xs:element name="color" type="xs:string" minOccurs="0"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="RestrictedProductType">
<xs:complexContent>
<xs:restriction base="ProductType">
<xs:sequence>
<xs:element name="number" type="xs:integer"/>
<xs:element name="name" type="xs:string"/>
</xs:sequence>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
Example 13-15. Eliminating meaningless groups
Base group:
<xs:sequence>
<xs:sequence>
<xs:element name="a"/>
<xs:element name="b"/>
</xs:sequence>
</xs:sequence>
Legal restriction:
<xs:sequence> <xs:element name="a"/> <xs:element name="b"/> </xs:sequence>
Example 13-16. Restricting element declarations
Base group:
<xs:sequence> <xs:element name="a" maxOccurs="3"/> <xs:element name="b" fixed="bValue"/> <xs:element name="c" type="xs:string"/> </xs:sequence>
Legal restriction:
<xs:sequence> <xs:element name="a" maxOccurs="2"/> <xs:element name="b" fixed="bValue"/> <xs:element name="c" type="xs:token"/> </xs:sequence>
Illegal restriction:
<xs:sequence> <xs:element name="a" maxOccurs="4"/> <xs:element name="b" fixed="newValue"/> <xs:element name="c" type="xs:integer"/> </xs:sequence>
Example 13-17. Replacing a wildcard with element declarations
Base group:
<xs:sequence> <xs:element name="a"/> <xs:any namespace="##other" maxOccurs="1"/> </xs:sequence>
Legal restriction:
<xs:sequence> <xs:element name="a"/> <xs:element ref="otherns:b"/> </xs:sequence>
Illegal restriction:
<xs:sequence> <xs:element name="a"/> <xs:element ref="b"/> <xs:element name="c"/> </xs:sequence>
Example 13-18. Replacing a wildcard with another wildcard
Base wildcard:
<xs:any namespace="urn:a:1 urn:a:2" maxOccurs="2"/>
Legal restriction:
<xs:any namespace="urn:a:1" maxOccurs="1"/>
Illegal restriction:
<xs:any namespace="##other" maxOccurs="3"/>
Example 13-19. Replacing a group with an element declaration
Base group:
<xs:sequence> <xs:element name="a"/> <xs:element name="b" minOccurs="0"/> </xs:sequence>
Legal restriction:
<xs:element name="a"/>
Example 13-20. Restricting occurrence constraints of a group
Base group:
<xs:sequence minOccurs="2" maxOccurs="5"> <xs:element name="a"/> <xs:element name="b"/> </xs:sequence>
Legal restriction:
<xs:sequence minOccurs="3" maxOccurs="4"> <xs:element name="a"/> <xs:element name="b"/> </xs:sequence>
Illegal restriction:
<xs:sequence minOccurs="0" maxOccurs="6"> <xs:element name="a"/> <xs:element name="b"/> </xs:sequence>
Example 13-21. Maintaining the order of the children in an all group
Base group:
<xs:all> <xs:element name="a"/> <xs:element name="b" minOccurs="0"/> <xs:element name="c"/> </xs:all>
Example 13-22. Restricting an all group
Base group:
<xs:all> <xs:element name="a"/> <xs:element name="b" minOccurs="0"/> <xs:element name="c"/> </xs:all>
Legal restriction:
<xs:all> <xs:element name="a"/> <xs:element name="c"/> </xs:all>
Example 13-23. Restricting a choice group
Base group:
<xs:choice> <xs:element name="a"/> <xs:element name="b"/> <xs:element name="c"/> </xs:choice>
Legal restriction:
<xs:choice> <xs:element name="a"/> <xs:element name="c"/> </xs:choice>
Illegal restriction:
<xs:choice> <xs:element name="a"/> <xs:element name="d"/> </xs:choice>
Example 13-24. Replacing an all group with a sequence group
Base group:
<xs:all> <xs:element name="a"/> <xs:element name="b" minOccurs="0"/> <xs:element name="c"/> </xs:all>
Legal restriction:
<xs:sequence> <xs:element name="a"/> <xs:element name="c"/> </xs:sequence>
Illegal restriction:
<xs:sequence> <xs:element name="a"/> <xs:element name="b"/> <xs:element name="c" minOccurs="2"/> </xs:sequence>
Example 13-25. Replacing a choice group with a sequence group
Base group:
<xs:choice maxOccurs="2"> <xs:element name="a"/> <xs:element name="b"/> <xs:element name="c"/> </xs:choice>
Legal restriction:
<xs:sequence> <xs:element name="a"/> <xs:element name="c"/> </xs:sequence>
Illegal restriction:
<xs:sequence> <xs:element name="a"/> <xs:element name="b"/> <xs:element name="c"/> </xs:sequence>
Example 13-26. Restricting open content
Base group:
<xs:complexType name="BaseType">
<xs:openContent mode="suffix">
<xs:any namespace="http://datypic.com/prod
http://datypic.com/ord"/>
</xs:openContent>
<xs:sequence>
<xs:element name="a" type="xs:string" minOccurs="0"/>
</xs:sequence>
</xs:complexType>
Legal restriction:
<xs:complexType name="LegalDerivedType">
<xs:complexContent>
<xs:restriction base="BaseType">
<xs:openContent mode="suffix">
<xs:any namespace="http://datypic.com/prod"/>
</xs:openContent>
<xs:sequence>
<xs:element name="a" type="xs:string" minOccurs="0"/>
</xs:sequence>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
Illegal restriction:
<xs:complexType name="IllegalDerivedType">
<xs:complexContent>
<xs:restriction base="BaseType">
<xs:openContent mode="interleave">
<xs:any namespace="##any"/>
</xs:openContent>
<xs:sequence>
<xs:element name="a" type="xs:string" minOccurs="0"/>
</xs:sequence>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
Example 13-27. Mixed content restriction
<xs:complexType name="LetterType" mixed="true">
<xs:sequence>
<xs:element name="custName" type="xs:string"/>
<xs:element name="prodName" type="xs:string"/>
<xs:element name="prodSize" type="xs:integer" minOccurs="0"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="RestrictedLetterType" mixed="true">
<xs:complexContent>
<xs:restriction base="LetterType">
<xs:sequence>
<xs:element name="custName" type="xs:string"/>
<xs:element name="prodName" type="xs:string"/>
</xs:sequence>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
Example 13-28. Mixed content restricted to simple content
<xs:complexType name="LetterType" mixed="true">
<xs:sequence minOccurs="0">
<xs:element name="custName" type="xs:string"/>
<xs:element name="prodName" type="xs:string"/>
<xs:element name="prodSize" type="xs:integer"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="RestrictedLetterType">
<xs:simpleContent>
<xs:restriction base="LetterType">
<xs:simpleType>
<xs:restriction base="xs:string"/>
</xs:simpleType>
</xs:restriction>
</xs:simpleContent>
</xs:complexType>
Example 13-29. Empty content restriction
<xs:complexType name="ItemType">
<xs:attribute name="routingNum" type="xs:integer"/>
</xs:complexType>
<xs:complexType name="RestrictedItemType">
<xs:complexContent>
<xs:restriction base="ItemType">
<xs:attribute name="routingNum" type="xs:short"/>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
Example 13-30. Legal restrictions of attributes
<xs:complexType name="BaseType">
<xs:attribute name="a" type="xs:integer"/>
<xs:attribute name="b" type="xs:string"/>
<xs:attribute name="c" type="xs:string" default="c"/>
<xs:attribute name="d" type="xs:string"/>
<xs:attribute name="e" type="xs:string" fixed="e"/>
<xs:attribute name="f" type="xs:string"/>
<xs:attribute name="g" type="xs:string"/>
<xs:attribute name="x" type="xs:string"/>
</xs:complexType>
<xs:complexType name="DerivedType">
<xs:complexContent>
<xs:restriction base="BaseType">
<xs:attribute name="a" type="xs:positiveInteger"/>
<xs:attribute name="b" type="xs:string" default="b"/>
<xs:attribute name="c" type="xs:string" default="c2"/>
<xs:attribute name="d" type="xs:string" fixed="d"/>
<xs:attribute name="e" type="xs:string" fixed="e"/>
<xs:attribute name="f" type="xs:string" use="required"/>
<xs:attribute name="g" type="xs:string" use="prohibited"/>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
Example 13-31. Illegal attribute restrictions
<xs:complexType name="BaseType2">
<xs:attribute name="h" type="xs:integer"/>
<xs:attribute name="i" type="xs:string" fixed="i"/>
<xs:attribute name="j" type="xs:string" fixed="j"/>
<xs:attribute name="k" type="xs:string" use="required"/>
<xs:attribute name="l" type="xs:string" use="required"/>
</xs:complexType>
<xs:complexType name="IllegalDerivedType">
<xs:complexContent>
<xs:restriction base="BaseType2">
<xs:attribute name="h" type="xs:decimal"/>
<xs:attribute name="i" type="xs:string" fixed="i2"/>
<xs:attribute name="j" type="xs:string" default="j"/>
<xs:attribute name="k" type="xs:string"/>
<xs:attribute name="l" type="xs:string" use="prohibited"/>
<xs:attribute ref="pref:l"/>
<xs:attribute name="m" type="xs:string"/>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
Example 13-32. Restricting an attribute wildcard
<xs:complexType name="BaseType">
<xs:anyAttribute processContents="lax" namespace="##any"/>
</xs:complexType>
<xs:complexType name="DerivedType">
<xs:complexContent>
<xs:restriction base="BaseType">
<xs:anyAttribute processContents="strict"
namespace="##targetNamespace
http://www.w3.org/1999/xhtml"/>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
Example 13-33. Replacing an attribute wildcard with attributes
<xs:complexType name="BaseType">
<xs:anyAttribute processContents="lax" namespace="##any"/>
</xs:complexType>
<xs:complexType name="DerivedType">
<xs:complexContent>
<xs:restriction base="BaseType">
<xs:attribute name="id" type="xs:ID" use="required"/>
<xs:attribute name="name" type="xs:string"/>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
Example 13-34. Restricting a type from another namespace with global declarations
prod.xsd
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
targetNamespace="http://datypic.com/prod"
xmlns:prod="http://datypic.com/prod"
elementFormDefault="qualified"
attributeFormDefault="qualified">
<xs:complexType name="ProductType">
<xs:sequence>
<xs:element ref="prod:number"/>
<xs:element ref="prod:name"/>
<xs:element ref="prod:size" minOccurs="0"/>
</xs:sequence>
<xs:attribute ref="prod:dept"/>
</xs:complexType>
<xs:element name="number" type="xs:integer"/>
<xs:element name="name" type="xs:string"/>
<xs:element name="size" type="xs:integer"/>
<xs:attribute name="dept" type="xs:string"/>
</xs:schema>
ord.xsd
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
targetNamespace="http://datypic.com/ord"
xmlns:prod="http://datypic.com/prod">
<xs:import namespace="http://datypic.com/prod"
schemaLocation="prod.xsd"/>
<xs:complexType name="RestrictedProductType">
<xs:complexContent>
<xs:restriction base="prod:ProductType">
<xs:sequence>
<xs:element ref="prod:number"/>
<xs:element ref="prod:name"/>
</xs:sequence>
<xs:attribute ref="prod:dept" use="required"/>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
</xs:schema>
Example 13-35. Using targetNamespace on element and attribute declarations
prod.xsd
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
targetNamespace="http://datypic.com/prod"
elementFormDefault="qualified"
attributeFormDefault="qualified">
<xs:complexType name="ProductType">
<xs:sequence>
<xs:element name="number" type="xs:integer"/>
<xs:element name="name" type="xs:string"/>
<xs:element name="size" type="xs:integer" minOccurs="0"/>
</xs:sequence>
<xs:attribute name="dept" type="xs:string"/>
</xs:complexType>
</xs:schema>
ord.xsd
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
targetNamespace="http://datypic.com/ord"
xmlns:prod="http://datypic.com/prod"
elementFormDefault="qualified"
attributeFormDefault="qualified">
<xs:import namespace="http://datypic.com/prod"
schemaLocation="prod.xsd"/>
<xs:complexType name="RestrictedProductType">
<xs:complexContent>
<xs:restriction base="prod:ProductType">
<xs:sequence>
<xs:element name="number" type="xs:integer"
targetNamespace="http://datypic.com/prod"/>
<xs:element name="name" type="xs:string"
targetNamespace="http://datypic.com/prod"/>
</xs:sequence>
<xs:attribute name="dept" type="xs:string" use="required"
targetNamespace="http://datypic.com/prod"/>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
</xs:schema>
<xs:complexType name="ProductType">
<xs:sequence>
<xs:element name="number" type="xs:integer"/>
<xs:element name="name" type="xs:string"/>
</xs:sequence>
</xs:complexType>
<xs:element name="product" type="ProductType"/>
Example 13-37. Substitution of ShirtType for ProductType
<items xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<product xsi:type="ShirtType">
<number>557</number>
<name>Short-Sleeved Linen Blouse</name>
<color>blue</color>
</product>
<!--...-->
</items>
Example 13-38. Preventing derivation
<xs:complexType name="ProductType" final="#all">
<xs:sequence>
<xs:element name="number" type="xs:integer"/>
<xs:element name="name" type="xs:string"/>
</xs:sequence>
</xs:complexType>
Example 13-39. Preventing substitution of derived types
<xs:complexType name="ProductType" block="extension">
<xs:sequence>
<xs:element name="number" type="xs:integer"/>
<xs:element name="name" type="xs:string"/>
</xs:sequence>
</xs:complexType>
<xs:element name="product" type="ProductType"/>
<xs:complexType name="ShirtType">
<xs:complexContent>
<xs:extension base="ProductType">
<xs:choice maxOccurs="unbounded">
<xs:element name="size" type="xs:integer"/>
<xs:element name="color" type="xs:string"/>
</xs:choice>
</xs:extension>
</xs:complexContent>
</xs:complexType>
<xs:element name="shirt" type="ShirtType"/>
Example 13-40. Illegal substitution of ShirtType
<product xsi:type="ShirtType"> <number>557</number> <name>Short-Sleeved Linen Blouse</name> <color>blue</color> </product>
Example 13-41. An abstract type
<xs:complexType name="ProductType" abstract="true">
<xs:sequence>
<xs:element name="number" type="xs:integer"/>
<xs:element name="name" type="xs:string"/>
</xs:sequence>
</xs:complexType>
<xs:element name="product" type="ProductType"/>
<xs:complexType name="ShirtType">
<xs:complexContent>
<xs:extension base="ProductType">
<xs:choice maxOccurs="unbounded">
<xs:element name="size" type="xs:integer"/>
<xs:element name="color" type="xs:string"/>
</xs:choice>
</xs:extension>
</xs:complexContent>
</xs:complexType>
<xs:element name="shirt" type="ShirtType"/>
Example 13-42. Legal instances of product and shirt
<product xsi:type="ShirtType"> <number>557</number> <name>Short-Sleeved Linen Blouse</name> <color>blue</color> </product> <shirt> <number>557</number> <name>Short-Sleeved Linen Blouse</name> <color>blue</color> </shirt>
Example 13-43. Illegal uses of the abstract ProductType
<product> <number>557</number> <name>Short-Sleeved Linen Blouse</name> </product> <product xsi:type="ProductType"> <number>557</number> <name>Short-Sleeved Linen Blouse</name> </product>