1. DR. JOHN ABRAHAM PROFESSOR UTPA
AJAX
DR. JOHN ABRAHAM
PROFESSOR
UTPA

2. The old way
If one wanted to get any information from a database on the server, or send user information to a server-side script like PHP, one had to make an HTML form to GET or POST data to the server; would then have to click "Submit", wait for the server to respond. Finally a new page would load with the results.

3. AJAX Asynchronous JavaScript and XML Makes use of
HTML
CSS
With AJAX, Internet applications can be made richer and more user-friendly.
With AJAX web applications look and feel like desktop applications.

4. AJAX
Uses client-side user interaction and server communication and run them in parallel, reducing the delays of server-side processing.
Uses JavaScript send asynchronous requests to the server and updates the page using the DOM.
Tool kits like DOJO hides portability issues of AJAX.

5. AJAX
The client side of Ajax applications is written using XHTML, CSS and javaScript.
XML is used to structure the data passed between the server and the client.
JavaScript’s XMLHttpRequest (XHR) is used to interact directly with the server.

6. Traditional Vs. Ajax Apps
Refer to fig 15.1 and fig 15.2 pp
Each page has to requested, generated, sent and rendered give blank screens in between (world wide wait, www.
With Ajax a layer is added between the client and server to manage communication. Requests are asynchronous so that the user has control over the page. Also allows partial page updates.

7. Sample program link