1. Understanding Ajax
Shyamala Prayaga
May 2009

2. Agenda
• Understanding Ajax
• Backbone of Ajax
• How Ajax works
Yodlee®, Inc. Copyright © 2009 - 5/14/2009 - CONFIDENTIAL 2

3. What is Ajax?
• Ajax stands for Asynchronous JavaScript and XML
• Not a new technology
• New technique for creating better, faster and interactive applications
Yodlee®, Inc. Copyright © 2009 - 5/14/2009 - CONFIDENTIAL 3

4. Ajax Backbone
• JavaScript
• XML
• HTML
• CSS
Yodlee®, Inc. Copyright © 2009 - 5/14/2009 - CONFIDENTIAL 4

5. How Ajax Works?
• JavaScript communicates directly with the server, through the
JavaScript XMLHttpRequest object.
• All new browsers use the built-in JavaScript XMLHttpRequest
object to create an XMLHttpRequest object
• IE5 and IE6 uses an ActiveXObject
Yodlee®, Inc. Copyright © 2009 - 5/14/2009 - CONFIDENTIAL 5

6. XMLHttpRequest object Properties
• onreadystatechange property - stores the function that will process
the response from a server
• readyState property - readyState property holds the status of the
server's response.
• responseText property - The data sent back from a server can be
retrieved with the responseText property.
Yodlee®, Inc. Copyright © 2009 - 5/14/2009 - CONFIDENTIAL 6

7. Sending response to the server
• open() method
– takes three arguments
– The first argument defines which method to use when sending
the request (GET or POST).
– The second argument specifies the URL of the server-side script.
– The third argument specifies that the request should be handled
asynchronously.
• Send() method
– sends the request off to the server.
Yodlee®, Inc. Copyright © 2009 - 5/14/2009 - CONFIDENTIAL 7

8. Questions?
Yodlee®, Inc. Copyright © 2009 - 5/14/2009 - CONFIDENTIAL 8