A Quick Intro to XML Does a letter have structure? How does XML look? What is XML? What are XML...

A Quick Intro to XML

• Does a letter have structure?

• How does XML look?

• What is XML? What are XML Documents?

• How does XML processing work?

• demos (editing/parsing, transformations )

• What resources are available?

Does a letter have structure?Thomas Bean

12000 Chelsea RoadLondon 5678

Fridges Internationalattn. Mrs Freezer900 Coolstreet Dover 2345

Concerning: The latest shipment of refried beans

Dear Mrs Freezer,

I am sorry to tell you that our latest shipment of beans of the brand Ulysses had some defects and needs to be withdrawn. Please send all cans back to the address given at the top. We will immediately start to send you the newly introduced brand Star at no additional cost.

Best regards(signature)Thomas Bean

Even the text of a letter contains some structure that can be „marked“ – Just try to mark something and give it a name

How does XML look?

An XML instance<?xml version="1.0" encoding="utf-8"?><!DOCTYPE teilnahmeb SYSTEM "teilnahmeschein.dtd" [

<!ENTITY lt "<"><!ENTITY gt ">"><!ENTITY amp "&"><!ENTITY class "XML BASIC">

]><teilnahmeschein Autor=„Kriha“>

<nachweis>Frau <teiln>Nina Schwarz</teiln> hat am <datum>22.9.98</datum> am Kurs <kursname>&class;</kursname> teilgenommen.<?Pub Caret?>

</nachweis><kursinfo>

<absatz>Introduction to XML </absatz></kursinfo><adresse>

<name>Walter Kriha</name><strasse>Schwarzwaldstr.7g</strasse>

</adresse></teilnahmeschein>

The Instance is the real document and contains the text of an author/writer. This instance claims that it is conformant with the DTD found in the system

entity „teilnahmeschein.dtd“

An XML DTD<!ELEMENT teilnahmeschein (nachweis,kursinfo,adresse,kommentar*)>

<!ATTLIST teilnahmeschein Autor #CDATA>

<!ELEMENT kommentar (#PCDATA)><!ELEMENT nachweis (#PCDATA | teiln | datum | kursname )*><!ELEMENT kursinfo (absatz+)><!ELEMENT adresse (name,strasse,ort)><!ELEMENT teiln (#PCDATA)><!ELEMENT datum (#PCDATA)><!ELEMENT kursname (#PCDATA)><!ELEMENT absatz (#PCDATA | hervorh | fussnote)*><!ELEMENT hervorh (#PCDATA)><!ELEMENT fussnote (absatz+)><!ELEMENT name (#PCDATA)><!ELEMENT strasse (#PCDATA)><!ELEMENT ort (#PCDATA)>

The DTD defines how a document is structured (what elements and attributes are required and in which order they may come)

Formal or Domain MarkupFORMAL

<message> <command target="accounting" id="1"> <process>update</process> <object class="GlAccount" oid="12345"

version="1"> <context> <owner class="ChartOfAccounts"

oid="47"/> </context> <property name="name">Bank

Account</property> <property name="type">Asset</property> <object name="balance" class="Money"> <property

name="currency">USD</property> <property name="amount"

type="float">15000.00</property> </object> </object> </command></message>

DOMAIN SPECIFIC

<message> <update target="accounting" id="1"> <GlAccount oid="12345" version="1"> <ChartOfAccounts oid="47"/> <GlAccount.name>Bank

Account</GlAccount.name> <GlAccount.type>Asset</GlAccount.type> <Balance> <Currency>USD</Currency> <Amount>15000.00</Amount> </Balance> </GlAccount> </update></message>

<table><row><col></col>

</row></table>

what kind of markup is this?

An XSL style sheet<?xml version="1.0" encoding="ISO-8859-1"?><xsl:stylesheet xmlns:xsl="http://www.w3.org/TR/WD-xsl" xmlns:html="http://www.w3.org/TR/REC-html40/" result-ns="html">

<xsl:template match="/"><HTML> <HEAD>

<xsl:for-each select="title"><title>

<xsl:process-children/></title>

</xsl:for-each></HEAD><body>

<xsl:process-children/></body>

</HTML></xsl:template><xsl:template match=”account">

<h1><xsl:process-children/>

</h1></xsl:template><xsl:template match=”firstname">

<p><xsl:process-children/>

----- more ---------

The bold parts match elementsfrom the xml input document

Xpointer/Xlink elements<?xml ver="1.0"?><!DOCTYPE doc PUBLIC "-//Masatomo Goto//DTD XLink sample document//EN" [<?STYLESHEET href="..\styles\sample_scroll.dsl" type="text/dsssl" ?>

]><doc><title>XLink and XPointer: how do I address and link things?</title>

<group steps="2"> <groupdoc href="dsssloverview.xml"/> <groupdoc href="readme.xml"/></group><xlink> <locator role="Hubdocument Title" href="myhub.xml#root().child( 1, title)"/> <locator role="Overview Title" href="readme.xml#root().child( 1, title)"/> <locator role="DSSSL Spec Reference" href="readme.xml#root().child( 1, chapter).(2, section).( 2, p)"/> <locator show="new" role="DSSSL Spec" href="dsssloverview.xml#root().child( 1, title)"/></xlink>

<xlink> <locator role="toc" href="#root().child( 2, chapter).(1, section).(4, p)"/> <locator role="cont." href="readme.xml#child( 1, chapter).(4, section).( 1, title)"/></xlink>

------ more ---------------

This Xlink connects 4 locations in 3 different documents. Every locator serves a

different role.

What is XML?

• A (meta)language to define document schemas and validate document instances

• A simplified and modernized version of SGML (Standard General Markup Lang.)

• NOT like html (but looks similiar)

• Content - not presentation oriented

• For machines AND humans

XML: Documents or Data?

XMLDocument

ConfigurationFiles

Data RecordsDirectory

Information

Reviews,Publications

FormsBooks,Letters

MultimediaContent

Reports

Document centric Data centric

Content Management SystemDatabase,

XML Server Middleware

Standards

• XML: Extensible Markup Language V1.0

• XSL: Extended Stylesheet Language

• XPath: A way to address things

• Xlink: A way to link things

• RDF: a way to express semantics

• Sax: Parser interface• DOM (Document Object

Model)• XSD: XML Schema

Definition Language• XHTML: the new HTML

in XML syntax

Advantages of XML information

• human and machine readable • no fixed tag set, any schema is possible• Content centric and self-describing• well-formed or valid• tool independence • A data definition in XML is descriptive code AND

its documentation – immediately usable by clients

Technical Terms 1

• DTD: Document Type Definition. A way to specify the structure and content of documents

• Instance: a concrete document• DOM (Document Object Model): A

way to programmatically access XML elements and attributes

Technical Terms 2

• Elements: The basic structures of a document

• Attributes: Meta-information about elements

• Entities: Kind of “macros” or includes

• Process. Instructions: hints for applications

<car>volvo</car>

<car color=„red“

<car>&bmw;</car>

<? handle separately>

Elements form the structure of a document. They can nest (have children). Note that both the start of an element and ist end (</xxxx>) are given.

How does XML processing work?

Parser Input: Instance + DTD<?xml version="1.0" encoding="utf-8"?><!DOCTYPE teilnahmeb SYSTEM "teilnahmeschein.dtd" [

<!ENTITY lt "<"><!ENTITY gt ">"><!ENTITY amp "&"><!ENTITY class "XML BASIC">

]><teilnahmeb>

<nachweis>Frau <teiln>Nina Schwarz</teiln> hat am <datum>22.9.98</datum> am Kurs <kursname>&class;</kursname> teilgenommen.<?Pub Caret?>

</nachweis><kursinfo>

<absatz>Introduction to XML </absatz></kursinfo><adresse>

<name>Walter Kriha</name><strasse>Schwarzwaldstr.7g</strasse>

</adresse></teilnahmeschein>

<!ELEMENT teilnahmeschein (nachweis,kursinfo,adresse,kommentar*)><!ELEMENT kommentar (#PCDATA)><!ELEMENT nachweis (#PCDATA | teiln | datum | kursname )*><!ELEMENT kursinfo (absatz+)><!ELEMENT adresse (name,strasse,ort)><!ELEMENT teiln (#PCDATA)><!ELEMENT datum (#PCDATA)><!ELEMENT kursname (#PCDATA)><!ELEMENT absatz (#PCDATA | hervorh | fussnote)*><!ELEMENT hervorh (#PCDATA)><!ELEMENT fussnote (absatz+)><!ELEMENT name (#PCDATA)><!ELEMENT strasse (#PCDATA)><!ELEMENT ort (#PCDATA)>

XML File to XML Application

XML file XML Parser Entity Manager

DB Storage manager

Http Storage manager

XML Application

Events

XML Application to DOM

XML App

startElementEvent(“memo”);

DOM Factorycontains different

node types

createElement(“memo”,…)

Element : Node

Tree of DOM nodes

teilnahmeschein as DOM tree

T e x tN o de"F ra u"

T e x tN o de"N in a S ch w a rz"

E le m e n tN o dete iln

T e x tN o de"2 2.9 .9 8"

E le m e n tN o ded atum

T e x tN o de"a m K u rs"

T e x tN o de"X M L B a s ic"

E le m e n tN o deku rsna m e

P INo deP u b Ca red

E le m e n tN o den a ch w e is

T e x tN o de"In trod u ctio n to X M L"

a b sa tz

E le m e n tN o deku rs in fo

T e x tN o de"W a lte r K rih a"

E le m e n tN o den am e

T e x tN o de"S ch w arzw a ld s tr. 7g

E le m e n tN o des tra sse

E le m e n tN o dea d resse

E le m e n tN o dete ilna hm eb

D o cu m en t No de

Server Side Processing

HTML Browser

Application

Web Server

Proposal.xml

Proposal.xslServlet

XSLEngine

Proposal.html

Applications get straight

XML

Html is generated on

the fly

Demo1: Editing/Parsing

• Parser: NSGMLS parser from James Clark• Editor: Morphon, XEmacs, XMLSpy,

wordpad, vi• Objective: What does it mean to

VALIDATE a document?• Resources: teilnahmeschein.dtd (a DTD),

teilnahmeschein.xml (a valid instance), teilnahmeschein1.xml (an invalid instance)

From DTDs to Schemas<?xml version="1.0" encoding="UTF-8"?><xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified">

<xs:element name="absatz"><xs:complexType mixed="true">

<xs:choice minOccurs="0" maxOccurs="unbounded"><xs:element ref="hervorh"/><xs:element ref="fussnote"/>

</xs:choice></xs:complexType>

</xs:element><xs:element name="adresse">

<xs:complexType><xs:sequence>

<xs:element ref="name"/><xs:element ref="strasse"/><xs:element ref="ort"/>

</xs:sequence></xs:complexType>

</xs:element>

<!ELEMENT teilnahmeb (nachweis,kursinfo,adresse,kommentar*)><!ELEMENT kommentar (#PCDATA)><!ELEMENT nachweis (#PCDATA | teiln | datum | kursname )*><!ELEMENT kursinfo (absatz+)><!ELEMENT adresse (name,strasse,ort)><!ELEMENT teiln (#PCDATA)><!ELEMENT datum (#PCDATA)><!ELEMENT kursname (#PCDATA)><!ELEMENT absatz (#PCDATA | hervorh | fussnote)*><!ELEMENT hervorh (#PCDATA)><!ELEMENT fussnote (absatz+)><!ELEMENT name (#PCDATA)><!ELEMENT strasse (#PCDATA)><!ELEMENT ort (#PCDATA)>

Job Description Format: an XML Schema

<?xml version="1.0" encoding="UTF-8"?>

<xsd:schema targetNamespace="http://www.CIP4.org/JDFSchema_1" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:jdfP="http://www.CIP4.org/JDFSchema_1/JDFParser"

xmlns:jdf="http://www.CIP4.org/JDFSchema_1" xmlns:xsd="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified"

attributeFormDefault="unqualified">



<xsd:complexType name="EmptyElement"/>

<xsd:complexType name="Comment_Type" mixed="true">

<xsd:simpleContent>

<xsd:extension base="xsd:string">

<xsd:attribute name="Box" type="jdf:rectangle" use="optional"/>

<xsd:attribute name="Language" type="xsd:language" use="optional"/>

<xsd:attribute name="Name" type="xsd:NMTOKEN" default="Description"/>

<xsd:attribute name="Path" type="jdf:path" use="optional"/>….....................

Please read the introduction to XSD (see resources)

Job Description Format Example

Please read the introduction to XSD (see resources)

<JDF ID=“n1" Type="Product" JobID=”some product ID"

Status=”Waiting" Version="0.9">

<NodeInfo/>

<CustomerInfo/>

<ResourcePool>

<SomeInputResource ID=“Link2" Class="Parameter" Status=”Available"/>

<Component ID=“Link3" Class="Quantity" Status=”Unavailable"

DescriptiveName="Some output resource"/>

</ResourcePool>

<ResourceLinkPool>

<SomeInputResourceLink rRef=Link2" Usage=”Input"/>

<ComponentLink rRef=“Link3" Usage=”Output"/>

</ResourceLinkPool>

<AuditPool/>

</JDF>

XML and HTML

XML is a language to define document types. HTML is a document type well suited for online publishing. What kind of elements do we need for online publishing?

something to create images

something to make a paragraph

title:

a title would be nice

how about sections and sub-sections?

tables are necessary

A

text could have special

meaning (expressed as bold, cursive

etc.)

a way to link to other documents

is needed

Demo2: XSL transformations

• XSL engine: saxon (java) or mozilla/firefox browser or IE

• Objective: What does it mean to TRANSFORM a document using stylesheets?

• Resources: catalog.xml/xsl, article.xml/xsl

• Results: html versions of those

XML Resources

• Robin Covers page, find everything about SGML/XML at: www.oasis-open.org/cover

• xml-dev: mailing list for XML developers• Charles Goldfarb, The XML Handbook• IBM xml tools in java: www.alphaworks.ibm.com • www.xmlsoftware.com (tools)• www.xml.com (news)• http://www.editor.net/intro.htm, explains writing

for the Internet• www.morphon.com (free editor for download)

XSL Resources

• http://www.webdevelopersjournal.com/articles/xml_to_html.html a good introduction to xsl conversions by Benoit Marchal (with samples)

• Michael Kay, Professional XML programming (the „bible“)

• frequently asked questions: http://www.dpawson.co.uk/xsl/sect1/sect1.html (excellent and free)

XML Schema (XSD) Resources

• http://www.w3schools.com/schema/ a short introduction to XSD with samples. We will need XSD for the Job Definition Format of the printing industry!

A Quick Intro to XML Does a letter have structure? How does XML look? What is XML? What are XML...

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Transcript of A Quick Intro to XML Does a letter have structure? How does XML look? What is XML? What are XML...