2005-5-2
ajax:a new approach to web applications
ajax
or asynchronous javascript and xml is a term coined by the adaptive
path consultancy
describing a web development technique for creating interactive web applications
using a combination of:
1.html
(or xhtml) and
cascading style
sheets for presenting information
2.document
object model,
javascript to
dynamically display and interact with the information presented
3.xml,
xslt and the
xmlhttprequest object
to interchange and manipulate data asynchronously with the web server (although
ajax applications can use other technologies, including plain text and
json , as alternatives to xml/xslt).
like
dhtml or lamp, ajax is not a technology in itself, but a
term that refers to the use of a group of technologies
together.
ajax applications use web
browsers that support the above technologies as a platform to run on. browsers
that support these technologies include mozilla firefox, internet explorer,
opera, and safari.
there are critics of the
term ajax, claiming that it is an acronym coined for techniques that were
already in use, although an acceptable term for these methods was not in regular
use beforehand. others claim that the adaptive path consultancy who created the
term are using it as a marketing vehicle.
contents
1 how
ajax applications differ from traditional web applications
2 pros and cons
3 adoption of ajax
4 external links
5
notes
how
ajax applications differ from traditional web applications
traditional web
applications allow users to fill out forms, and when these forms are submitted,
a request is sent to a web server. the web server acts upon whatever was sent by
the form, and then responds back by sending a new web page. a lot of bandwidth
is wasted since much of the html from the first page is present in the second
page. furthermore, this method can impede creating rich user interfaces.
ajax applications, on the
other hand, can send requests to the web server to retrieve only the data that
is needed, usually using soap or some other xml-based web
services dialect, and using javascript in the client to process the web server
response. the result is more responsive applications, since the amount of data
interchanged between the web browser and web server is vastly reduced. web
server processing time is also saved, since a lot of this is done on the
computer from which the request came.
