What is Dojo and Ajax

It is impossible to talk about Dojo without making reference to Ajax. Before we define and discuss these technologies, let's briefly investigate the challenges encountered by web applications as well as portal applications.

The problem

Dynamic web applications heavily rely on the Application Server to maintain a user session. The interaction with the user and consequently the session maintenance is performed through the processing of request and response objects leading to the rendering of a full web page. This process needs to be done synchronously.

Throughout the session life of a web application, there can be many requests to return the same page, but with small changes. This brings us to the core of the problem. Even for the smallest changes, traditional web applications require a full page reload.

Concerning Portal, this limitation is even more problematic because in order to respond to changes to update the content of one portlet, all the portlets on a page need...