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Rajesh Math

10/17/2012SICSR XML - Lecture 11

XML - Session 1

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Overview

10/17/2012SICSR XML - Lecture 1

An XML example

so whats so special about XML?

The birth of the Web -- HTML

HTML is not enough -- why?

XML for universal data

Common uses and applications

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XML test.xml

Title of text XHTML Document

Heading of Page

here is a paragraph of text. I will include inside this paragraph a bunchof

wonky text so that it looks fancy.

Here is another paragraph with inline emphasized text,and

absolutely no sense of humor.

And here is another paragraph, this one containing an inline image, and a line break.

10/17/2012 SICSR XML - Lecture 1

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HTML

10/17/2012SICSR XML - Lecture 1

The HyperText Markup LanguageA simplelanguage for distributing text

Started with very few tags

Language evolved, as more tags were added forms

tables

fonts

frames

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HTML Problems

10/17/2012SICSR XML - Lecture 1

Desire forpersonalizedtags

Want to put data into HTML form

mathematics, database entries, literary text, poems,

purchase orders .

HTML just isnt designed for that!

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HTML Problems

Software processing

Server management of

data

But -- HTML is so ill-formed, this is hard!

10/17/2012 SICSR XML - Lecture 1

HTML

HTML

HTML

HTML

HTML

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SGML

10/17/2012SICSR XML - Lecture 1

HTML was defined using SGML Standard Generalized Markup Language

A meta-language for defining languages.

Complex, sophisticated, powerful

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XML

10/17/2012SICSR XML - Lecture 1

New eXtensible Markup Language: XML

Can use XML to define new languages

Distributeseasily on the Web

Can mixdifferent types of data together

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Basic XML Rules

10/17/2012SICSR XML - Lecture 1

Tags like in HTML, but ...

Technical details

Always need end tags Special empty-elementtags

Always quoteattribute values

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XML:Data Abstraction

10/17/2012SICSR XML - Lecture 1

XML as a universal formatfor data interchange

Machines exchange data as XML-format messages

Eliminates proprietary data formats

Lots of XML processing software available

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10/17/2012 SICSR XML - Lecture 1

XML Messaging

DatabaseOther DB

Other DB

Other DB

Request/send data

Request/send data

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XML (Contd)

10/17/2012SICSR XML - Lecture 1

a frameworkfor distributing data on the Web

an integrationtool for mixing different types ofdata

a universal formatfor exchanging data betweenmachines

XML Parsers process XML Documents