Intuitive and natural user interaction
No clicking required
Mouse movement is a sufficient event trigger
"Partial screen update" replaces the "click,
wait, and refresh" user interaction model
Only user interface elements that contain new information
are updated (fast response)
The rest of the user interface remains displayed without
interruption (no loss of operational context)
Asynchronous communication replaces "synchronous
request/response model"
A user can continue to use the application while the client
program requests information from the server in the background
Separation of displaying from data fetching Conclusion.
Technologies Used in AJAX
Javascript
Loosely typed scripting language
Allows programmatic interaction with the browser's
capabilities
JavaScript function is called when an event in a page occurs
HTTP
XMLHttpRequest
DOM
API for accessing and manipulating structured documents
Represents the structure of XML and HTML documents
CSS
Allows for a clear separation of the presentation from the
content and may be changed programmatically by JavaScript
Client-side: XMLHttpRequest
JavaScript object
Created within a JavaScript function
Adopted by modern browsers
Mozilla™, Firefox, Safari, and Opera
Communicates with a server via standard HTTP GET/POST
XMLHttpRequest object works in the background
Does not interrupt user operation
Server-Side: AJAX Request Processing
Server programming model remains the same
It receives standard HTTP GETs/POSTs
Can use Servlet, JSP, JSF
With minor constraints
More frequent granular requests from client
Response content type needs to be text/xml
Ajax mind share
Ajax has dominated the web application arena for quite
sometime. The one strength Ajax has is that it is based on reliable web
standards: The W3C gave us HTML, CSS, XML and DOM, and ECMA giving using
JavaScript (or more technically correct EcmaScript). It is a wonderfully
natural combination of technologies, especially for people involved in
developing and supporting e-commerce applications.
