Advantages And Disadvantages Of An Ajax-based Client

Application

Irinel BucurAndreea Bucur

• Ajax (also AJAX; an acronym for Asynchronous JavaScript and XML) is a group of interrelated web development methods used on the client-side to create asynchronous web applications.

• Despite the name, the use of XML is not needed (JSON is often used instead), and the requests do not need to be asynchronous.

What is Ajax?

A little history

• In ‘90s, most websites were based on complete HTML pages;

• In ’95 when Java Applets were introduced, Asynchronous loading of content became practical;

• In ‘96, Internet Explorer introduced IFRAME element which enables asynchronous loading as well.

A little history – Thanks to Microsoft

• In April 2000, Microsoft patented the basic Ajax technology, granted in 2006.

• In ‘99, Microsoft created XMLHttp ActiveX control which was adopted later by Mozilla, Opera, Safari as XMLHttpRequest JavaScript object.

• In 2006, W3C released the first draft for XMLHttpRequest specifications in order to create an official web standard.

Traditional vs. Ajax model

• While the server is doing its thing, what’s the user doing?

Traditional vs. Ajax model - 2

Transferred data

• Merrill found a 61% improvement due to the use of AJAX.

• AJAX application transferred on average 27% of the bytes that the traditional HTML application transferred.

• White reported a 73% performance increase for bytes transferred and 16% increase in server generating query.

* Smullen - White reported a 73% performance increase for bytes transferred – March 2008 (http://www.academypublisher.com/jsw/vol03/no03/jsw03033037.pdf)

Advantages

• Source code can be very well structured.• 73% performance increase in terms of used

bandwidth.• Maintain only one server-side code for Mobile and

other browsers.• Maintenance costs are cheaper.• New server side developments are easy to

implement.• Ajax source code can be tested automatically.• User input can get server side validated on the fly.

Disadvantages

• High costs to implement the solution.• Server load is increased by 16%.• Deployment is not very fast since it may involve lots

of scripts to get uploaded.• New programmers needs long training period.• Experienced designers are needed.• A small change in look and feel may not be all the

time easy and fast to implement.• Costs with the servers hardware may increase.

Questions?

Questions?

Thank you

Thank you!