introduction to xml

Introduction to XML

Eugenia FernandezIUPUI

What is XML? From the World Wide Web

Consortium (W3C) The Extensible Markup Language (XML)

is the universal format for structured documents and data on the web.

It is a tag-based markup language that both describes data and is used to create markup languages for specific contexts.

XML-derived Markup Languages

Open Financial Exchange (OFX) XML/EDI

Markup for Electronic Data Interchange Resource Description Framework

Markup for describing data about data (metadata) for cataloging and search purposes

Chemical markup Language (CML) Wireless Markup Language (WML)

A Document Contains Data

Structure

Presentation

XML

Style sheets(CSS, XSL)

Unstructured vs.Structured Data

diluvio m. Inundación causada por lluvias copiosas. Lluvia muy copiosa.

Unstructured

<word>diluvio</word><type>m.</type><definition>Inundación causada por lluvias copiosas. Lluvia muy copiosa.</definition>

Structured

History of XML SGML (Standard Generalization Markup

Language) was developed as a way to express data in electronic texts

XML is simplified subset of SGML, designed to work across a limited-bandwidth network such as the Internet.

XML is in process of being standardized. It is currently at the recommendation stage.

XML vs. HTML

<html><b>101 Main St.<br>Chicago, IL 60661</b></html>

<?xml version=”1.0” ?><address>

<street>101 Main St.</street><city>Chicago</city><state>IL</state><zip>60661</zip>

</address>

HTML = presentation format

XML = structured content

Why XML? Readable format Distribute data to any machine on

any platform Easily combine multiple sources of

data Easier way to do data interchange

between applications

Benefits of Using XML Describes content and structure Both machine- and human- readable Separates content from display Well-formed, follows rules Can be validated Open and extensible One source – multiple formats

Conversion

One Source – Multiple Formats

Separating data from presentation and processing frees the data from any one use

Data becomes "use neutral"

XML

HTML

PDF

XML

Processing XML into HTML

XSLStylesheet

XSLProcessor

HTML Document

XMLDocument

Processing XML to XML

XSLStylesheet

XSLProcessor

NewXML

Document

XMLDocument

How XML Can Be Used Enable business-to-business

communication Enable smart agents Enable smart searches XML data can be manipulated by

the browser reducing server & network load

A Few XML Technologies Extensible Markup Language (XML) 1.0 Cascading Style Sheets (CSS) Extensible Style Language (XSL)

XML Document Transformation (renamed XSLT) XPath, a pattern matching syntax XSLFO, a formatting object interpretation, for

printing XML Pointer Language (XPointer) and

XML Linking Language (XLink) Document Type Definition (DTD) XML Schemas (XSD)

Contents of XML Document

Processing instructions

Comments Elements

Root Element Child Element Empty

Element Attributes Text

<?xml version=“1.0“?>



<student_list> <name>John Smith</name> <full_time/> <email type=“home”> [email protected] </email></student_list>

XML Data is Hierarchical

<?xml version=“1.0”?>



<student> <name>John Smith</name> <full_time/> <email type=“home”> [email protected] </email></student>

student

name

full_time

email

type

John Smith

[email protected]

home

Well-formed Documents Contain single root element Match open and close tags Consistent capitalization Correctly nested elements All attributes enclosed in quotes No repeating attributes in an

element

Validation of XML Documents Ensures that document is

grammatically correct Validation done via

Document Type Definition (DTD) XML Schema

validformedWell

References MSDN DevSeries, Web 105:

Introduction to XML Microsoft Class Pack: Building XML-

Based Web Applications, Module 1: Overview of XML Documents

XML Seminar at Quilogy, May 9, 2001

Introduction to XML, a Barnes & Noble University Online Course