Web Tech Class 5

8/8/2019 Web Tech Class 5

1/13

Mr. Debojit Boro

Assistant Professor,Tezpur University,Napaam,Tezpur-784028

Web Technology

Batches:

M.Tech. 2nd Semester

B.Tech 6th Semester

B.Tech. 8th Semester

MCA 4th Semester

B.Tech. Electronics 8th Semester


2/13

Topics for today

XML HTTP Request

XML Parser

Mr. Debojit Boro

Assistant Professor,Tezpur University,Napaam,Tezpur-784028


3/13

XMLHttpRequest

XMLHttpRequest is used to communicatewith your server from inside a web page.

Update a web page with new data withoutreloading the page

Request and receive new data from a server

after the page has loaded Communicate with a server in the

background


4/13

Creation of XMLHttpRequest

var xmlhttp=new XMLHttpRequest()

Or in IE 5 or 6

var xmlhttp=new ActiveXObject("Microsoft.XMLHTTP")


5/13

XML Parsing

Two approaches forXML Parsing

XML Doc

SAXApproach

DOM Approach

String of Elements

Tree Like Structure


6/13

Everyday Italian

Giada De Laurentiis

2005

30.00

XML Document

SAX (Simple API for XML) ll look like

StartElement:bookstore

StartElement:book

StartElement:title

Characters: Everyday Italian

EndElement:title


7/13

Sequential Approach(SAX) also

know as Simple API for XML

It is an incremental approach

Signals the application program about the

start and end of elements

Deals with only single element at a time

Considers data to be made up of string of

elements

It concentrate just on the current and not onthe XML Document in totality


8/13

Document Object Model(DOM)

This approach treats the XML Document as

a tree like structure

Loads the entire XML document into the

memory Compiles the XML Doc into an internal tree

Converts the elements and attributes into

nodes of the tree


9/13

XML Parser

The XML DOM contains methods (functions)to traverse XML trees, access, insert, anddelete nodes.

However, before an XML document can beaccessed and manipulated, it must be loadedinto an XML DOM object.

An XML parser reads XML, and converts it

into anX

ML DOM object that can beaccessed with JavaScript.

Most browsers have a built-in XML parser.


10/13

if (window.XMLHttpRequest) {

xhttp=new XMLHttpRequest();

}

else // for older IE 5/6

{

xhttp=new ActiveXObject("Microsoft.XMLHTTP");

} xhttp.open("GET","books.xml",false);

xhttp.send("");

xmlDoc=xhttp.responseXML;

document.write("XML document loaded into an XML DOM Object.");

Code for loading of XML Document


11/13

XML VS HTML

XML and HTML are not alternative to each other

They are complement to each other

HTML is for presentation

XML for meaningful encoding

To display an XML document we have to transform to HTML

XHTML is the XML version of HTML

If we display raw XML document we may get only a tree view

Tree View XML Example

We can display an XML document with CSS Example with css

We can also display by transforming XML to HTML by XSL


12/13

XML Transformation

XML document can be transformed to another

XML document or to HTML XML content needs to be transformed to HTML

if we want the content to be displayed by the

browser

XSL (eXtensible Stylesheet Language) capturesthe rues of transformation

XSL also follows XML syntax

In the XML file include this reference


13/13

Classwork

Create an XML document that describes your details in the following

hierarchy

Name LastName

FirstName

MiddleName

Age Years

Months

Address Country

State

CityPin

Phone Country code

Area code

Phone number

Documents

Web Tech Class 5