w3schools    w3Schools
Search W3Schools :
   
HOME HTML CSS XML JAVASCRIPT ASP PHP SQL MORE...   References Examples Forum About
ADVERTISEMENTS

XML Certification
Download XML editor
Custom Programming
 
Table of contents
PHP Basic
PHP HOME
PHP Intro
PHP Install
PHP Syntax
PHP Variables
PHP String
PHP Operators
PHP If...Else
PHP Switch
PHP Arrays
PHP Looping
PHP Functions
PHP Forms
PHP $_GET
PHP $_POST

PHP Advanced
PHP Date
PHP Include
PHP File
PHP File Upload
PHP Cookies
PHP Sessions
PHP E-mail
PHP Secure E-mail
PHP Error
PHP Exception
PHP Filter

PHP Database
MySQL Introduction
MySQL Connect
MySQL Create
MySQL Insert
MySQL Select
MySQL Where
MySQL Order By
MySQL Update
MySQL Delete
PHP ODBC

PHP XML
XML Expat Parser
XML DOM
XML SimpleXML

PHP and AJAX
AJAX Introduction
XMLHttpRequest
AJAX Suggest
AJAX XML
AJAX Database
AJAX responseXML
AJAX Live Search
AJAX RSS Reader
AJAX Poll

PHP Reference
PHP Array
PHP Calendar
PHP Date
PHP Directory
PHP Error
PHP Filesystem
PHP Filter
PHP FTP
PHP HTTP
PHP Libxml
PHP Mail
PHP Math
PHP Misc
PHP MySQL
PHP SimpleXML
PHP String
PHP XML
PHP Zip

PHP Quiz
PHP Quiz
PHP Exam

Selected Reading
Web Statistics
Web Glossary
Web Hosting
Web Quality

W3Schools Tutorials
W3Schools Forum

Helping W3Schools

 

AJAX XMLHttpRequest

Previous Next

The XMLHttpRequest object makes AJAX possible.


The XMLHttpRequest

The XMLHttpRequest object is the key to AJAX.

It has been available ever since Internet Explorer 5.5 was released in July 2000, but not fully discovered before people started to talk about AJAX and Web 2.0 in 2005.


Creating An XMLHttpRequest Object

Different browsers use different methods to create an XMLHttpRequest object.

Internet Explorer uses an ActiveXObject.

Other browsers uses a built in JavaScript object called XMLHttpRequest.

Here is the simplest code you can use to overcome this problem:

var XMLHttp=null;
if (window.XMLHttpRequest)
  {
  XMLHttp=new XMLHttpRequest();
  }
else if (window.ActiveXObject)
  {
  XMLHttp=new ActiveXObject("Microsoft.XMLHTTP");
  }

Example above explained:

  1. First create a variable XMLHttp to use as your XMLHttpRequest object. Set the value to null.
  2. Then test if the object window.XMLHttpRequest is available. This object is available in newer versions of Firefox, Mozilla, Opera, and Safari.
  3. If it's available, use it to create a new object: XMLHttp=new XMLHttpRequest()
  4. If it's not available, test if an object window.ActiveXObject is available. This object is available in Internet Explorer version 5.5 and later.
  5. If it is available, use it to create a new object: XMLHttp=new ActiveXObject()

A Better Example?

Some programmers will prefer to use the newest and fastest version of the XMLHttpRequest object.

The example below tries to load Microsoft's latest version "Msxml2.XMLHTTP", available in Internet Explorer 6, before it falls back to "Microsoft.XMLHTTP", available in Internet Explorer 5.5 and later.

function GetXmlHttpObject()
{
var xmlHttp=null;
try
 {
 // Firefox, Opera 8.0+, Safari
 xmlHttp=new XMLHttpRequest();
 }
catch (e)
 {
 // Internet Explorer
 try
  {
  xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
  }
 catch (e)
  {
  xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
  }
 }
return xmlHttp;
}

Example above explained:

  1. First create a variable XMLHttp to use as your XMLHttpRequest object. Set the value to null.
  2. Try to create the object according to web standards (Mozilla, Opera and Safari):XMLHttp=new XMLHttpRequest()
  3. Try to create the object the Microsoft way, available in Internet Explorer 6 and later:XMLHttp=new ActiveXObject("Msxml2.XMLHTTP")
  4. If this catches an error, try the older (Internet Explorer 5.5) way: XMLHttp=new ActiveXObject("Microsoft.XMLHTTP")

More about the XMLHttpRequest object

If you want to read more about the XMLHttpRequest, visit our AJAX tutorial.


Previous Next


Altova® MissionKit® - Integrated suite of XML tools

The Altova MissionKit is a suite of intelligent XML tools, including:

XMLSpy® – industry-leading XML editor

  • Support for all XML-based technologies
  • Graphical editing views, powerful debuggers, code generation, & more

MapForce® – graphical data mapping tool

  • Drag-and-drop data conversion with code generation
  • Support for XML, DBs, EDI, Excel® 2007, text, Web services

StyleVision® – visual stylesheet designer

  • Drag-and-drop stylesheet design for XML & databases
  • Output to HTML, PDF, RTF, Word 2007, & more

And more…

Try before you buy with a free fully functional 30-day trial

Download today




diploma   

Get Your Diploma!

W3Schools' Online Certification Program is the perfect solution for busy professionals who need to balance work, family, and career building.

The HTML Certificate is for developers who want to document their knowledge of HTML, XHTML, and CSS.

The JavaScript Certificate is for developers who want to document their knowledge of JavaScript and the HTML DOM.

The XML Certificate is for developers who want to document their knowledge of XML, XML DOM and XSLT.

The ASP Certificate is for developers who want to document their knowledge of ASP, SQL, and ADO.

The PHP Certificate is for developers who want to document their knowledge of PHP and SQL (MySQL).


 
WEB HOSTING
ASP.NET Web Hosting
ASP.NET
Web Hosting
$15 Domain Name
Registration
Save $20 / year!
Buy UK Domain Names
Register Domain Names
Cheap Domain Names
Cheap Web Hosting
Best Web Hosting
PHP MySQL Hosting
Top 10 Web Hosting
UK Reseller Hosting
Web Hosting
FREE Web Hosting
WEB BUILDING
Website Templates
Flash Templates
Website Builder
Internet Business Opportunity
Custom Programming
FREE Trial or Demo
Web Content Manager
Forms,Web Alerts,RSS
Download XML editor
FREE Flash Website
FREE Web Templates
EDUCATION
US Web Design Schools
HTML Certification
JavaScript Certification
XML Certification
PHP Certification
ASP Certification
Home HOME or Top of Page Validate   Validate   W3C-WAI level A conformance icon Printer Friendly  Printer Friendly

W3Schools is for training only. We do not warrant the correctness of its content. The risk from using it lies entirely with the user.
While using this site, you agree to have read and accepted our terms of use and privacy policy.
Copyright 1999-2009 by Refsnes Data. All Rights Reserved.