AJAX Development and Outsourcing, AJAX Application Solutions at Web Spiders
AJAX stands for Asynchronous JavaScript and XML. Although AJAX has been available
for the last 8 years, its utility was not realized until recently – Web Spiders
being one of the forerunners in realizing the ability of AJAX and put it to proper
use in web applications.
AJAX offers a versatile platform for developing rich web applications that are highly
interactive and behave just like desktop applications adding up to the usability
and availability of web applications that serve enterprise business services. At
Web Spiders, applications using AJAX harness this capability and get the most out
of it.
The term AJAX was invented by Jesse James Garrett that described a collection of
technologies that allows a rich user experience to web users.
AJAX combines the following technologies
- XML and XSLT for data exchange
- HTML or XHTML as mark up language
- CSS for creating custom styles
- Document Object Model (DOM)
- Client-end scripting language like JavaScript
- XMLHttpRequest object for asynchronous data exchange with the web server
From programming perspective AJAX enables a new way of combining client side programming
in JavaScript with server side processing that deliver XML chunks to web pages.
This allows web pages to be updated with new data without any need to reload the
entire data.
How does AJAX work?
AJAX eliminates page refreshes by handling the requested operations in JavaScript
and calling the server side operations in an asynchronous mode to display the necessary
result.
The AJAX engine works as a mediator between the client and server. When the session
starts, the AJAX engine is first loaded, unlike other technologies where the web
page is loaded first. The job of this engine is to render the user interface and
start communicating with the server on behalf of the user. From client-end, the
engine enables asynchronous interaction between the user and application.
An AJAX script makes a request to the server by using the JavaScript XMLHttpRequest
object. This is a special JavaScript object that invokes a URL and makes requests
without a single page refresh. This XMLHttpRequest object retrieves information
from the server and presents it to the user. The most remarkable feature of the
engine is that it does not fetch any information from the server that is already
cached, resulting in a swift information fetch for the application and a smooth
and pleasurable experience for the user.
Coding AJAX
Coding an AJAX application involves creating XMLHttp object. This is a JavaScript
object that can be created like this:
<script language=”JavaScript” type=”text/javascript”>
var xmlHttp=new XMLHttprequest();
</script>
In Internet Explorer this is how the request appears:
http = newActiveXObject(“Microsoft.XMLHTTP”);
This XMLHttpRequest object handles all server communication and it is the JavaScript
technology that talks to the server through this object.
In AJAX, when data is submitted through a form it does not go directly to the server;
instead it goes to the JavaScript code. The JavaScript in turn sends the request
to the server. When this takes place, the user’s screen never refreshes and the
user is free to perform other screen activities while the processing continues and
results are fetched in a very short time.
Browser compatibility with AJAX
AJAX is becoming a global technology that is supported by most of the Browsers.
Some of these are as follows:
- Microsoft Internet Explorer 5.0 and above
- Netscape 7.1 and above
- Mozilla, Mozilla Firefox
- Apple Safari version 1.2 and above
- Opera browser version 8.0 and above
AJAX has been an innovation in technology. At Web Spiders, it is a revelation for
web solutions that get the most out of AJAX to deliver cutting edge software solutions
to customers.