An Introduction to XML and Web Technologies
XML Documents
Anders Møller & Michael I. Schwartzbach
©2006Addison-Wesley
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An Introduction to XML and Web Technologies
Objectives
What is XML , in particular in relation to HTML The XML data model and its textual reprentation
The XML Namespace mechanism
3An Introduction to XML and Web Technologies
What is XML?
XML: E x tensible M arkup L anguage
A framework for defining markup languages Each language is targeted at its own
application domain with its own markup tags There is a common t of generic tools for processing XML documents
XHTML : an XML variant of HTML
Inherently internationalized and platform independent (Unicode )
Developed by W3C, standardized in 1998
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An Introduction to XML and Web Technologies Recipes in XML
Define our own “Recipe Markup Language ”
Choo markup tags that correspond to concepts in this application domain
•recipe , ingredient , amount , ...
No canonical choices
•granularity of markup?•structuring?
•elements or attributes?•
...
5An Introduction to XML and Web Technologies
Example (1/2)
<collection>
<description>Recipes suggested by Jane Dow</description><recipe id="r117">
<title>Rhubarb Cobbler</title><date>Wed, 14 Jun 95</date>
<ingredient name="diced rhubarb" amount="2.5" unit="cup"/><ingredient name="sugar" amount="2" unit="tablespoon"/><ingredient name="fairly ripe banana" amount="2"/>
<ingredient name="cinnamon" amount="0.25" unit="teaspoon"/><ingredient name="nutmeg" amount="1" unit="dash"/><preparation><step>
Combine all and u as cobbler, pie, or crisp.</step>
</preparation>
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An Introduction to XML and Web Technologies Example (2/2)
<comment>
Rhubarb Cobbler made with bananas as the main sweetener.It was delicious.</comment>
<nutrition calories="170" fat="28%"
carbohydrates="58%" protein="14%"/>
<related ref="42">Garden Quiche is also yummy</related></recipe></collection>
7An Introduction to XML and Web Technologies
Building on the XML Notation卵磷脂有什么功效
Defining the syntax of our recipe language
•DTD, XML Schema, ...
Showing recipe documents in browrs
•XPath, XSLT
Recipe collections as databas
•XQuery
Building a Web-bad recipe editor
•HTTP, Servlets, JSP, ...
...
–the topics of the
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姚文利An Introduction to XML and Web Technologies XML Trees
Conceptually, an XML document is a tree structure
•node, edge •root, leaf •child, parent
•
sibling (ordered), ancestor,descendant
9An Introduction to XML and Web Technologies An Analogy: File Systems 10
An Introduction to XML and Web Technologies Tree View of the XML Recipes
寒假实践11An Introduction to XML and Web Technologies
Nodes in XML Trees
Text nodes : carry the actual contents, leaf nodes Element nodes : define hierarchical logical groupings of contents, each have a name
Attribute nodes : unordered, each associated with an element node, has a name and a value Comment nodes : ignorable meta-information Processing instructions : instructions to specific processors, each have a target and a value
Root nodes : every XML tree has one root node that reprents the entire tree
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An Introduction to XML and Web Technologies Textual Reprentation
Text nodes : written as the text they carry Element nodes : start-end tags •<bla ...>... </bla >
•short-hand notation for empty elements: <bla /> Attribute nodes : name =“value ”in start tags Comment nodes : <!--bla -->
Processing instructions : <?target value ?> Root nodes : implicit
13An Introduction to XML and Web Technologies Browsing XML (without XSLT)
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An Introduction to XML and Web Technologies More Constructs
XML declaration
Character references CDATA ctions
Document type declarations and entity references
Whitespace?
15An Introduction to XML and Web Technologies
Example
<?xml version="1.1" encoding="ISO-8859-1"?><!DOCTYPE features SYSTEM "example.dtd"><features a="b">
<?mytool here is some information specific to mytool?>El ñor estábien, garçon!Copyright © 2005
<![CDATA[ <this is not a tag> ]]><!--always remember to specify the
right character encoding -->
</features>
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An Introduction to XML and Web Technologies Well -formedness
Every XML document must be well-formed
•start and end tags must match and nest properly •<x><y></y></x>9
•</z><x><y></x></y>
•exactly one root element •...
in other words, it defines a proper tree structure
XML parr : given the textual XML document,
constructs its tree reprentation
17An Introduction to XML and Web Technologies
Simpler Alternatives?
S-expressions, 1958:
(collection (recipe
(title "Rhubarb Cobbler") (date "Wed, 14 Jun 95")...))
XML is defined as a simplified subt of SGML XML could have been ... but it wasn’t [end of discussion]
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An Introduction to XML and Web Technologies Applications
墨子怒耕柱子
Rough classification:
Data-oriented languages
Document-oriented languages
Protocols and programming languages Hybrids
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An Introduction to XML and Web Technologies Example: XHTML <?xml version="1.0" encoding="UTF-8"?>
<html xmlns="/1999/xhtml"><head><title>Hello world!</title></head><body>
<h1>This is a heading</h1>This is some text.</body></html>
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An Introduction to XML and Web Technologies
Example: CML
<molecule id="METHANOL"><atomArray>
<stringArray builtin="id">a1 a2 a3 a4 a5 a6</stringArray><stringArray builtin="elementType">C O H H H H</stringArray><floatArray builtin="x3" units="pm">-0.748 0.558 ...</floatArray>
<floatArray builtin="y3" units="pm">-0.015 0.420 ...</floatArray>
好玩英语<floatArray builtin="z3" units="pm">0.024 -0.278 ...</floatArray></atomArray></molecule>
21An Introduction to XML and Web Technologies Example: ebXML
<MultiPartyCollaboration name="DropShip"><BusinessPartnerRole name="Customer">
<Performs initiatingRole='//binaryCollaboration[@name="Firm Order"]/
InitiatingRole[@name="buyer"]' />
</BusinessPartnerRole>
<BusinessPartnerRole name="Retailer">
<Performs respondingRole='//binaryCollaboration[@name="Firm Order"]/
RespondingRole[@name="ller"]' />
<Performs initiatingRole='//binaryCollaboration[...]/
InitiatingRole[@name="buyer"]' />
</BusinessPartnerRole>
<BusinessPartnerRole name="DropShip Vendor">...
</BusinessPartnerRole></MultiPartyCollaboration>
天鹅蛋怎么吃22
An Introduction to XML and Web Technologies
Example: ThML
<h3 class="s05" id="One.2.p0.2">Having a Humble Opinion of Self</h3><p class="First" id="One.2.p0.3">EVERY man naturally desires knowledge <note place="foot" id="One.2.p0.4">
<p class="Footnote" id="One.2.p0.5"><added id="One.2.p0.6"><name id="One.2.p0.7">Aristotle</name>, Metaphysics, i. 1.</added></p></note>;
but what good is knowledge without fear of God? Indeed a humble rustic who rves God is better than a proud intellectual who neglects his soul to study the cour of the stars.
<added id="One.2.p0.8"><note place="foot" id="One.2.p0.9"><p class="Footnote" id="One.2.p0.10">Augustine, Confessions V. 4.</p>
</note></added></p>
23An Introduction to XML and Web Technologies
XML Namespaces
When combining languages, element names may become ambiguous !
Common problems call for common solutions
<widget type="gadget"><head size="medium"/>
<big><subwidget ref="gizmo"/></big><info><head>
<title>Description of gadget</title></head><body>
<h1>Gadget</h1>两面国
A gadget contains a big gizmo </body></info></widget>
采购员岗位职责24
An Introduction to XML and Web Technologies The Idea
Assign a URI to every (sub-) /1999/xhtml for XHTML 1.0
Qualify element names with URIs:
{/1999/xhtml}head
