Xml Tarun Sujan

What Is XML? XML stands for EXtensible Markup

Language XML is a markup language much like HTML XML was designed to carry data, not to display data XML tags are not predefined. We must define our own tags XML is designed to be self-descriptive XML is a W3C Recommendation

Difference between XML and HTML XML was designed to carry data, not displaying

data

XML has no predefined tags Different goals:

XML was designed to describe data and to focus on what data is. HTML was designed to display data and to focus on how data looks. HTML is about displaying information, XML is

about describing information.

Why Do We Need XML? XML Separates Data from HTML XML Simplifies Data Sharing XML Simplifies Data Transport XML Simplifies Platform Changes XML is Used to Create New Internet

Languages

Data Sharing-XML J A V A

Partnership via Shared Information

Partner 1

Partner 2

Marshalling

XML

N E T

DTD XSLT

In

et n r te

Unmarshalling

XML

XML Syntax  All XML elements must have a closing tag  XML tags are case sensitive  All XML elements must be properly nested  All XML documents must have a root tag  Attribute values must always be quoted  With XML, white space is preserved  With XML, a new line is always stored as LF  Comments in XML:

Structure of an XML document Content Here

<EMPTY/>



An example of XML <note> Rani PARSE TREE Raja Message 9872108977

XML document life cycle

XML Document XSL Style Sheet

XML Parser TransFormatio n (XSLT)

Formatting (XSL-FO) Formatted Output

Result Tree

Why Is XML Important?  Plain Text Easy to edit  Useful for storing small amounts of data  Possible to efficiently store large amounts of XML data through an XML front end to a database 

 Data Identification Tell you what kind of data you have  Can be used in different ways by different applications 

Why Is XML Important?  Stylability  XSL---Extensible Style sheet Language  Different XSL formats can then be used to

display the same data in different ways

 Hierarchical  Faster to access  Easier to rearrange

XML Building blocks Element Delimited by angle brackets Identify the nature of the content they surround General format: <element> … Empty element:

Attribute Name-value pairs that occur inside start-tags after element name, like: <element attribute=“value”>

XML Elements XML Elements are Extensible XML documents can be extended to carry more information

XML Elements have Relationships Elements are related as parents and children

Elements have Content Elements can have different content types: element content, mixed content, simple content, or empty content and attributes

XML elements must follow the naming

rules

XML Attributes Located in the start tag of elements Provide additional information about elements Often provide information that is not a part of

data Must be enclosed in quotes

Displaying XML XML documents do not carry information about

how to display the data We can add display information to XML with  CSS (Cascading Style Sheets)  XSL (eXtensible Stylesheet Language) --- preferred

What is XSL? Preferred style sheet language of XML  a method for transforming XML documents  a method for formatting XML documents

 XSL consists of three parts:  XSLT - a language for transforming XML

documents  XPath - a language for navigating in XML documents  XSL-FO-a language for formatting in XML documents

CSS & XSL CSS XSL Can be used with HTML? yes

no

Can be used with XML?

yes

yes

Transformation language? yes Syntax

no CSS

XML

XML Application1—Separate data XML can Separate Data from HTML  Store data in separate XML files  Using HTML for layout and display

Benefits: Changes in the underlying data will not require any changes to your HTML

XML Application2—Exchange data XML is used to Exchange Data  Text format  Software-independent, hardware-independent  Exchange data between incompatible systems, given that

they agree on the same tag definition.

Benefits:  Reduce the complexity of interpreting data  Easier to expand and upgrade a system

XML Application3—Store Data XML can be used to Store Data  Plain text file  Store data in files or databases  Application can be written to store and retrieve information

from the store  Other clients and applications can access your XML files as data sources

Benefits: Accessible to more applications

XML Application4—Create new language XML can be used to Create new Languages  WML (Wireless Markup Language) used to markup Internet

applications for handheld devices like mobile phones (WAP)  MusicXML used to publishing musical scores

Document Type Declaration ]> <note> Tove Jani Reminder Don't forget me this weekend!

What is XSLT? XSLT stands for XSL Transformations XSLT transforms an XML document into another

XML document XSLT is a W3C Recommendation XSLT uses XPath to find information in an XML document.  XPath is used to navigate through elements and attributes in XML documents.

Simple XML File 
1"?>     Belgian Waffles  <price>$5.95  <description> two of our famous Belgian Waffles  650  

XSLT Style Sheet   -
xmlns="http://www.w3.org/1999/xhtml"> - - <xsl:for-each select="breakfast_menu/food"> - -      
Converted HTML File

What is XPath? XPath is a syntax for defining parts of an XML

document XPath uses path expressions to navigate in XML documents XPath contains a library of standard functions XPath is a major element in XSLT XPath is a W3C Standard

- -     Giada De Laurentiis   2005   <price>40.00   -     J K. Rowling   2005   <price>29.99   -   Selecting title Nodes with Price>35 /bookstore/book[price>35]/title

What is XQuery? XQuery is the language for querying XML data XQuery for XML is like SQL for databases XQuery is built on XPath expressions XQuery is supported by all the major database

engines (IBM, Oracle, Microsoft, etc.) XQuery is a W3C Recommendation

Web services The basic Web services platform is XML

+ HTTP. The HTTP protocol is the most used Internet protocol. XML provides a language which can be used between different platforms and programming languages and still express complex messages and functions. Web services platform elements  SOAP

(Simple Object Access Protocol)  UDDI (Universal Description, Discovery and Integration)

What is WSDL? WSDL is an XML-based language for

describing Web services and how to access them. WSDL stands for Web Services Description Language WSDL is written in XML WSDL is an XML document WSDL is also used to locate Web services WSDL is not yet a W3C standard

What is UDDI? UDDI is a directory service where businesses

can register and search for Web services. UDDI stands for Universal Description, Discovery and Integration UDDI is a directory for storing information about web services UDDI is a directory of web service interfaces described by WSDL UDDI communicates via SOAP UDDI is built into the Microsoft .NET platform

References www.google.com

XML tutorial

http://www.w3schools.com/w3c/ A technical introduction to XML http://www.xml.com/pub/a/98/10/guide0.ht ml

Thank you!

Queries?