1. 4
XML Schema

2. XML Schema Based on XML grammar, tools and technology
Alternative to DTD syntax
XML Schema (W3C)
Definition in accordance with the XML syntax
Allows the definition of complex data types

3. Validation Content Model Validation DTD Content Model Validation
XML Schema Part 1: Structures
XML Schema (W3C)
Content Model Validation
Datatype Validation
XML Schema Part 2: Datatypes

4. Features Data typing concept
Data types for attributes and element content
User-defined data types
Detailed and flexible content modeling
Attribute and element grouping
Refinement of content models, inheritance
Modularization
Self-documentation
Namespace support

5. Example <?xml version="1.0" encoding="utf-8"?>
<book isbn=" ">
<title>Being a Dog Is a Full-Time Job</title>
<author>Charles M. Schulz</author>
<character>
<name>Snoopy</name>
<friend-of>Peppermint Patty</friend-of>
<since> </since>
<qualification>extroverted beagle</qualification>
</character>
<name>Peppermint Patty</name>
<since> </since>
<qualification>bold, brash and tomboyish</qualification>
</book>
library.xml

6. Elements and Attributes
<?xml version="1.0" encoding="utf-8"?>
<xsd:schema xmlns:xsd="
....
Element Declaration
<xsd:element name="name" type="xsd:string"/>
<xsd:element name="friend-of" type="xsd:string"
minOccurs="0" maxOccurs="unbounded"/>
<xsd:element name="since" type="xsd:date"/>
....
Built-in simple Type
Cardinality
<xsd:attribute name="isbn" type="xsd:string"/>
....
Attribute Declaration
</xsd:schema>

7. Simple Data Types string normalizedString boolean byte number long
Built-in simple Types
string
boolean
number
float
double
decimal
duration
datetime
time
date
...
normalizedString
byte
long
int
short
positiveInteger
negativeInteger
unsignedLong
unsignedShort
...
Built-in Types derived from simple Types

8. "Russian Doll Design" Schema
<?xml version="1.0" encoding="utf-8"?>
<xsd:schema xmlns:xsd="
<xsd:element name="book">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="title" type="xsd:string"/>
<xsd:element name="author" type="xsd:string"/>
<xsd:element name="character" minOccurs="0" maxOccurs="unbounded">
<xsd:element name="name" type="xsd:string"/>
<xsd:element name="friend-of" type="xsd:string“
minOccurs="0" maxOccurs="unbounded"/>
<xsd:element name="since" type="xsd:date"/>
<xsd:element name="qualification" type="xsd:string"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:attribute name="isbn" type="xsd:string"/>
</xsd:schema>
Element of type complexType
Compositor

9. "Salami Slice Design" Schema
<?xml version="1.0" encoding="utf-8"?>
<xsd:schema xmlns:xsd=“
<xsd:element name="title" type="xsd:string"/>
<xsd:element name="author" type="xsd:string"/>
<xsd:element name="name" type="xsd:string"/>
<xsd:element name="friend-of" type="xsd:string"/>
<xsd:element name="since" type="xsd:date"/>
<xsd:element name="qualification" type="xsd:string"/>
<xsd:attribute name="isbn" type="xsd:string"/>
Definition of Elements of type "simple"
Definition of Attributes

10. "Salami Slice Design" Schema
<xsd:element name="character">
<xsd:complexType>
<xsd:sequence>
<xsd:element ref="name"/>
<xsd:element ref="friend-of"
minOccurs="0" maxOccurs="unbounded"/>
<xsd:element ref="since"/>
<xsd:element ref="qualification"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
<xsd:element name="book">
<xsd:element ref="title"/>
<xsd:element ref="author"/>
<xsd:element ref="character"
<xsd:attribute ref="isbn"/>
</xsd:schema>
Definition of "complexType" Elements

11. Schema with "Named Types"
<?xml version="1.0" encoding="utf-8"?>
<xsd:schema xmlns:xsd="
<xsd:simpleType name="nameType">
<xsd:restriction base="xsd:string">
<xsd:maxLength value="32"/>
</xsd:restriction>
</xsd:simpleType>
<xsd:simpleType name="sinceType">
<xsd:restriction base="xsd:date"/>
<xsd:simpleType name="descType">
<xsd:restriction base="xsd:string"/>
<xsd:simpleType name="isbnType">
<xsd:pattern value="[0-9]{10}"/>
Facet
Definition of "named simpleTypes"
Facet

12. ... Schema with "Named Types"
<xsd:complexType name="characterType">
<xsd:sequence>
<xsd:element name="name" type="nameType"/>
<xsd:element name="friend-of" type="nameType"
minOccurs="0" maxOccurs="unbounded"/>
<xsd:element name="since" type="sinceType"/>
<xsd:element name="qualification" type="descType"/>
</xsd:sequence>
</xsd:complexType>
<xsd:complexType name="bookType">
<xsd:element name="title" type="nameType"/>
<xsd:element name="author" type="nameType"/>
<xsd:element name="character" type="characterType"
<xsd:attribute name="isbn" type="isbnType" use="required"/>
<xsd:element name="book" type="bookType"/>
</xsd:schema>
Definition of "named complexTypes"
Declaration of book Element

13. Grouping Attributes and Elements
<xsd:group name="mainBookElements">
<xsd:sequence>
<xsd:element name="title" type="nameType"/>
<xsd:element name="author" type="nameType"/>
</xsd:sequence>
</xsd:group>
<xsd:attributeGroup name="bookAttributes">
<xsd:attribute name="isbn" type="isbnType" use="required"/>
<xsd:attribute name="available" type="xsd:string"/>
</xsd:attributeGroup>
<xsd:complexType name="bookType">
<xsd:sequence>
<xsd:group ref="mainBookElements"/>
<xsd:element name="character“ type="characterType"
minOccurs="0" maxOccurs="unbounded"/>
</xsd:sequence>
<xsd:attributeGroup ref="bookAttributes"/>
</xsd:complexType>

14. Compositors <xsd:group name="nameTypes"> <xsd:choice>
<xsd:element name="name" type="xsd:string"/>
<xsd:sequence>
<xsd:element name="firstName" type="xsd:string"/>
<xsd:element name="middleName" type="xsd:string" minOccurs="0"/>
<xsd:element name="lastName" type="xsd:string"/>
</xsd:sequence>
</xsd:choice>
</xsd:group>
<xsd:complexType name="bookType">
<xsd:all>
<xsd:element name="title" type="xsd:string"/>
<xsd:element name="author" type="xsd:string"/>
<xsd:element name="character" type="characterType"
minOccurs="0" maxOccurs="unbounded"/>
</xsd:all>
<xsd:attribute name="isbn" type="isbnType" use="required"/>
</xsd:complexType>

15. Derivations from Simple Types
xsd:restriction
xsd:maxLength, xsd:minLength
xsd:minInclusive,xsd:maxInclusive
xsd:totalDigits, xsd:fractionDigits ....
xsd:pattern
xsd:union
xsd:list
...
Facets

16. Content Types Empty Content with Attribute
<xsd:element name="book">
<xsd:complexType>
<xsd:attribute name="isbn" type="isbnType"/>
</xsd:complexType>
</xsd:element>
Empty Content with Attribute
<xsd:element name="book">
<xsd:complexType>
<xsd:simpleContent>
<xsd:extension base="xsd:string">
<xsd:attribute name="isbn" type="isbnType"/>
</xsd:extension>
</xsd:simpleContent>
</xsd:complexType>
</xsd:element>
Character Data Content with Attribute

17. Mixed Content <xsd:element name="book">
<xsd:complexType mixed="true">
<xsd:all>
<xsd:element name="title" type="xsd:string"/>
<xsd:element name="author" type="xsd:string"/>
</xsd:all>
<xsd:attribute name="isbn" type="xsd:string"/>
</xsd:complexType>
</xsd:element>
<book isbn=" ">
Funny book by <author>Charles M. Schulz</author>.
Its title (<title>Being a Dog Is a Full-Time Job</title>) says it all!
</book>

18. Documentation <xsd:element name="book"> <xsd:annotation>
<xsd:documentation xml:lang="en"> Top level element. </xsd:documentation>
<xsd:documentation xml:lang="fr"> Element racine </xsd:documentation>
<xsd:appinfo source="
<bind xmlns="
<class name="Book"/> </bind>
</xsd:appinfo>
</xsd:annotation> ...

19. Namespaces library.xsd library.xml <xsd:schema
xmlns:xsd="
xmlns="
targetNamespace="
elementFormDefault="unqualified"
attributeFormDefault="unqualified" >
....
</xsd:schema>
library.xsd
<book isbn=" " xmlns="
<title> Being a Dog is a Full-Time Job </title>
...
</book>
library.xml

20. XML Schema and Instances
<xsd:schema
xmlns:xsd="
....
</xsd:schema>
library.xsd
without targetNamespace
<book isbn=" "
xmlns:xsi="
xsi:noNamespaceSchemaLocation="library.xsd">
<title> Being a Dog is a Full-Time Job </title>
...
</book>
library.xml

21. ... XML Schema and Instances
<xsd:schema
xmlns:xsd="
xmlns="
targetNamespace="
....
</xsd:schema>
library.xsd
with targetNamespace
<book isbn=" "
xmlns:xsi="
xmlns="
xsi:schemaLocation=" library.xsd">
<title> Being a Dog is a Full-Time Job </title>
...
</book>
library.xml

22. Summary
Schema languages apply and enhance the concepts of DTDs to a more modern and consistent level.
XML Schema can construct very complex content models. Moreover, it supports a complex datatyping concept.