Analysis and Testing of Ajax-based Single-page Web Applications

Figure 1.6 Screen shot of Google Suggest. As a web user types search keywords,
the application retrieves suggestions from the server at the background, and shows
them to the user without having to refresh the whole page.
The term Ajax served to highlight and give a name to a new breed of web
applications that could be seen as a further evolution of the classical web.
Although many of the technologies Ajax is based on are not new, this naming
by Garrett made web developers aware of the possibilities for adopting a new
way of developing applications on the web. Figure 1.5 depicts the classical
synchronous interaction pattern compared with the asynchronous pattern of
an Ajax application.
For more technical details we refer to Appendix A, which describes a simple
single-page Ajax-based example application.
Although there have been some disagreements (Koch, 2005) on what Ajax
is exactly, how new it is, and which essential components the technology
is constituted from, a general acceptance of the fundamental concepts has
been achieved within the web community. The acceptance has mainly been
driven by the many concrete Ajax examples Google has been working on
(even before the term Ajax was coined) from Google Suggest (Figure 1.6),
Google Maps, Gmail, to porting desktop applications like Word to web-based
versions like Google Documents (Figure 1.7).
When we take a look at such applications from a user’s perspective, the
main difference, with respect to classical web applications, is the increased
responsiveness and interactivity. A refresh of the entire page is generally not
seen any longer for each user action and the interaction takes place at a much
finer granularity level.
When compared to RIA technologies such as OpenLaszlo, the main difference
and advantage is that no plugin is required, since Ajax is based on web
standards that modern browsers support already.
Chapter 1. Introduction 9