SlideServe
Télécharger Obtenir Pro
Menu
Accueil Pro
Préférences
ApparenceLight Aide et commentaires
© SlideServe · v2026

Introduction to XML Schema: Overview and Development of Web Services

liliha avatar
liliha
14 diapositives · 318 Views · Aug 14, 2014

This document provides a comprehensive introduction to XML Schema and its essential role in web services, discussing its development and structure. It covers key elements such as the transition from Document Type Definition (DTD) to XML Schema, the definition of elements, and the creation of complex types. The tutorial includes examples of XML schema definitions, common data types, empty elements, and attributes. Also highlighted are mechanisms for managing optional attributes and element values, offering practical insights for developers working with XML in web services.

Introduction to XML Schema: Overview and Development of Web Services - slide 1
01 / 14Introduction to XML Schema: Overview and Development of Web Services
1 / 17

Télécharger la présentation

Introduction to XML Schema: Overview and Development of Web Services
Une image / un lien ci-dessous est fourni (tel quel) pour télécharger la présentation

Politique de téléchargement : le contenu du site vous est fourni TEL QUEL pour votre information et votre usage personnel ; il ne peut être vendu, concédé sous licence ni partagé sur d’autres sites sans l’accord de son auteur.Le contenu vous est fourni TEL QUEL, pour votre information et votre usage personnel uniquement. Téléchargez la présentation en cliquant sur ce lien. Lors du téléchargement, si vous ne parvenez pas à télécharger une présentation, l’éditeur a peut-être supprimé le fichier de son serveur.Pendant le téléchargement, si vous ne parvenez pas à obtenir une présentation, le fichier a peut-être été supprimé par l’éditeur.

F I N

Plus de contenu associé

Transcription de la présentation

  1. XML Schema 3 – 4 June 2004 www.eu-egee.org EGEE is a project funded by the European Union under contract IST-2003-508833

  2. Objectives • Development background • xs:schema element • General structure • overall structure • Annotations • Defining elements • Associating documents with schemas Introduction to web services, 3-4 June 2004 - 2

  3. Development of Schema • Originally the tags in a XML document were defined in Document Type Definition (DTD) document. • This was not itself a XML document. • DTDs could be inline or separate documents. • DTDs did not inherently define namespaces • So schemas were developed which were XML documents, are separate from instances and namespaces were integral. Introduction to web services, 3-4 June 2004 - 3

  4. Reference to a Schema <?xml version="1.0"?> <note xmlns="http://www.nesc.ac.uk" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.nesc.ac.uk note.xsd"> <to>Tove</to> <from>Jani</from> <heading>Reminder</heading> <body>Don't forget me this weekend!</body> </note> Introduction to web services, 3-4 June 2004 - 4

  5. Simple Schema <?xml version="1.0"?> <xs:schema xmlns:xs=http://www.w3.org/2001/XMLSchema targetNamespace="http://www.nesc.ac.uk" xmlns="http://www.nesc.ac.uk" > <xs:element name="note"> <xs:complexType> <xs:sequence> <xs:element name="to" type="xs:string"/> <xs:element name="from" type="xs:string"/> <xs:element name="heading" type="xs:string"/> <xs:element name="body" type="xs:string"/> </xs:sequence> </xs:complexType> </xs:element> </xs:schema> Introduction to web services, 3-4 June 2004 - 5

  6. Common Schema data types • xs:string • xs:decimal • xs:integer • xs:boolean • xs:date • xs:time Introduction to web services, 3-4 June 2004 - 6

  7. Defining Elements • Elements defined with element element • Name given by name attribute • Content and attributes given in two ways: • content of element element defines type • or type attribute refers to type <xs:element name="order"> <xs:complexType> ... </xs:complexType> </xs:element> <xs:element name="order" type="order" /> <xs:complexType name="order"> ... </xs:complexType> Introduction to web services, 3-4 June 2004 - 7

  8. Defining Text-Only Elements • Text-only elements have simple type • basic type is xs:string • also do numbers with xs:decimal • more simple data types later <xs:element name="surname" type="xs:string" /> <surname>Poe</surname> <xs:element name="price" type="xs:decimal" /> <price>24.99</price> Introduction to web services, 3-4 June 2004 - 8

  9. Defining Empty • Empty elements have complex type with no content <xs:element name="br"> <xs:complexType /> </xs:element> <br /> Introduction to web services, 3-4 June 2004 - 9

  10. Open Elements • Unconstrained elements are of type xs:anyType • default when no type is specified <xs:element name="description" /> <description> This can contain <emph>any</emph> content at all. </description> Introduction to web services, 3-4 June 2004 - 10

  11. Defining Element Values • Apply to Post-Schema-Validation Infoset (PSVI) • available to stage after validation • Values fixed on element definition • default attribute gives default <xs:element name="surname" type="xs:string" default="Doe" /> <surname /> Functionally equivalent <surname>Doe</surname> Introduction to web services, 3-4 June 2004 - 11

  12. Fixed attribute fixed attribute gives fixed (or null) value <xs:element name="surname" type="xs:string" fixed="Doe" /> <surname /> valid <surname>Doe</surname> valid <surname>Smith</surname> invalid Introduction to web services, 3-4 June 2004 - 12

  13. Missing Element Values • Element still validated even if has no value • only allowed if nillable is true • xsi:nil="true" used in instance <xs:element name="date-of-birth" type="xs:date" nillable="true"/> <date-of-birth>1972-05-30</date-of-birth> valid <date-of-birth /> invalid <date-of-birth xsi:nil="true"/> valid Introduction to web services, 3-4 June 2004 - 13

  14. Making an attribute optional • All attributes are optional by default. To explicitly specify that the attribute is optional, use the "use" attribute: • <xs:attribute name="lang" type="xs:string" use="optional“ /> • To make an attribute required: • <xs:attribute name="lang" type="xs:string" use="required“ /> Introduction to web services, 3-4 June 2004 - 14