petros kavassalis

1

Enterprise IT[Πληροφοριακές Τεχνολογίες της Επιχείρησης]

Lecture 6-9: XSD Overview

Univ. of the Aegean Financial and Management Engineering Dpt

Petros KAVASSALIS<pkavassalis@atlantis-group.gr>

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What you will learn in this course

A set of fundamental concepts for understanding basic Enterprise Information Technologies Enterprise Software Applications Enterprise Architecture Integration (EAI)

Best practices and techniques for building and migrating to a service-oriented enterprise

Strategies for integrating applications using standard technologies XML Web Services

Familiarization with concepts such as: Interoperability e-business e-government 2.0

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Communication tools

e-mail: pkavassalis@atlantis-group.gr Course web site: see FME web site

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Students evaluation

Class Participation (20%)

+ Assignments (20%)

+ Final Exam (650%)

First go to http://www.w3schools.com/Schema/default.asp

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XSD in a nutshell

XML: XML Schema Definition Language XML Working Group at W3C (please visit!)

Used for the definition of XML tags and structure … the content and the structure of a class of XML documents

Schemas provide capabilities for expressing XML documents (the “logical structure” of the XML document Support for metadata characteristics

o Relationshipso Cardinalityo Valid Valueso Data Types

XML documents without a referenced schema cannot be “validated” If validated, the XML document has a valid construction… Note: “Simple”, “short” XML documents do not necessarily require the use of an XSD

scheme

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XSD: components

Schema components = building blocks Elements declarations Attribute declarations Simple Type definitions Complex Type definitions Notifications etc…

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XSD: architecture (1)

<?xml version=“1.0” encoding=“UTF-8”?><xsd:schema>

NAMESPACE

BODY</xsd/schema>

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Root element

XSD: architecture (2)

<pkavassalis@atlantis-group.gr> 9J. Bean (2003)

XSD: Global and Local Elements

Global Elements: Available to be used in the rest of the schema They are declared at the top level of the schema (BODY)

o This declaration determines how the element will look like They are “referenced” each time we want to use somewhere in the

schema Local Elements: Elements “on the spot”

They may not be used elsewhere in the schema Their names are “locally” unique, i.e. unique only in the context in

which they appear

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XSD: Simple Types

Elements with a built-in Type <xsd:element name=“label”

type=“xsd:datatype”/> xml

<label>data</label>

<xsd:element name=“weight” type=“xsd:string”/>

xml <weight>200 kg</weight>

Custom Simple Types <xsd:simpleType

name=“kapaType”><xsd:restriction

base=“xsd:datatype”><xsd:pattern value=“pattern”/></xsd:restriction>

</xsd:simpleType> xml

<kapa>data</kapa>

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XSD: Simple TypesExample

<xsd:element name="car" type="carType"/>

<xsd:simpleType name="carType">  <xsd:restriction base="xsd:string">    <xsd:enumeration value="Audi"/>    <xsd:enumeration value="Golf"/>    <xsd:enumeration value="BMW"/>  </xsd:restriction></xsd:simpleType>

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XSD: built-in DataTypes and limitations for Simple Types

Data and Time Types (built-in) Number Types (built-in) Other built-in Types

Locate them

Acceptable Values foe simple Types Patterns for simple Types Range of Acceptable Values for simple Types Length Limits for simple Types Number’s Digits Length for simple Types

List Types Element’s Content: pre-definition

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XSD: Restrictions/Facets for Datatypes

http://www.w3schools.com/Schema/schema_elements_ref.asp Restrictions/Facets for Datatypes

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XSD: Complex Types

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Complex Types

<xsd:complexType name=“kapaType”><xsd:sequence><xsd:element name=“lamda”

type=”lamdaType”/></xsd:sequence>

</xsd:complexType

Simple Types

<xsd:simpleType name=“kapaType”><xsd:restriction

base=“xsd:datatype”><xsd:pattern value=“pattern”/></xsd:restriction>

</xsd:simpleType> xml

<kapa>data</kapa>

XSD: Complex TypesExplicitly naming the xml element (restricted)

xml<employee>

  <firstname>John</firstname>  <lastname>Smith</lastname>

</employee> xsd

<xsd:element name="employee">  <xsd:complexType>    <xsd:sequence>      <xsd:element name="firstname" type="xsd:string"/>      <xsd:element name="lastname" type="xsd:string"/>    </xsd:sequence>  </xsd:complexType>

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XSD: Complex TypesSeveral elements can refer to a complex type

xml<employee>

  <firstname>John</firstname>  <lastname>Smith</lastname>

</employee> xsd

<xsd:element name="employee" type="personinfo"/><xsd:complexType name="personinfo">  <xs:dsequence>    <xsd:element name="firstname" type="xsd:string"/>    <xsd:element name="lastname" type="xsd:string"/>  </xsd:sequence></xsd:complexType>

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XSD: Complex TypesExtend a complex element

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<xsd:element name="employee" type="fullpersoninfo"/>

<xsd:complexType name="personinfo">  <xsd:sequence>    <xsd:element name="firstname" type="xsd:string"/>    <xsd:element name="lastname" type="xsd:string"/>  </xsd:sequence></xsd:complexType>

<xsd:complexType name="fullpersoninfo">  <xsd:copmlexContent>    <xsd:extension base="personinfo">      <xsd:sequence>        <xsd:element name="address" type="xsd:string"/>        <xsd:element name="city" type="xsd:string"/>        <xsd:element name="country" type="xsd:string"/>      </xsd:sequence>    </xsd:extension>  </xsd:complexContent></xsd:complexType>

XSD: Complex TypesXSD Elements

http://www.w3schools.com/Schema/schema_elements_ref.asp XSD Elements

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Set of choices Elements appearing with no order Max-Min Occurs Groups of elements

Referencing a named group How many elements?

XSD Attributes xml

o <lastname lang="EN">Smith</lastname> xsd

o <xsd:attribute name="lang" type="xsd:string"/>

XSD: Complex TypesChoice, Order and Groups

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XSD: Complex TypesEmpty Elements

Empty Elements xml

o <product prodid="1345" /> xsd

o <xsd:element name="product">  <xsd:complexType>    <xsd:attribute name="prodid" type="xsd:positiveInteger"/>  </xsd:complexType></xsd:element>

xsd (2)o <xsd:element name="product" type="prodtype"/>4

<xsd:complexType name="prodtype">  <xsd:attribute name="prodid" type="xsd:positiveInteger"/></xsd:complexType>

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XSD: Complex TypesElements with Mixed Content

Text-Only Elements (text, attributes)

<xsd:element name="somename">  <xsd:complexType    <xsd:simpleContent>      <xsd:extension base="basetype">        ....        ....      </xsd:extension>    </xsd:simpleContent>  </xsd:complexType></xsd:element>

Mixed Elements xml

<letter>  Dear Mr.<name>John Smith</name>.  Your order <orderid>1032</orderid>  will be shipped on <shipdate>2001-07-13</shipdate>.</letter>

xsd <xsd:element name="letter" type="lettertype"/>

<xsd:complexType name="lettertype" mixed="true">  <xsd:sequence>    <xsd:element name="name" type="xsd:string"/>    <xsd:element name="orderid" type="xsd:positiveInteger"/>    <xsd:element name="shipdate" type="xsd:date"/>  </xsd:sequence></xsd:complexType><pkavassalis@atlantis-group.gr> 22

XSD: Complex TypesMore

<any> <anyAttribute> Substitution

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XSD: Simple & Complex Types

All in One http://www.codeguru.com/java/article.php/c13529 (*) http://www.learn-xml-schema-tutorial.com/

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XSD: Complex TypesExamples

http://www.w3schools.com/Schema/schema_example.asp http://www2.it.lut.fi/kurssit/08-09/CT30A2900/Lectures/Exam

ples/An XML schema example.pdf

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[References]

E. Castro, 2001, XML for the World Wide Web, Peachpit Press Chapters 5, 6, 7, 8, 9

J. Bean, 2003, XML for Data Architects, Morgan Kaufmann Pub. Chapter 4

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