1. The Evolution of the Web Page
The Web was originally intended to help researchers share documents as static pages of linked text formatted in HTML. From there, Web pages quickly evolved to include complex structures of text and graphics, with plug-in programs to play audio and video files or to stream multimedia content. Web developers supplement the basic browser function of rendering HTML by invoking code (scripts) on the user's computer (the client). These scripts can create interface elements such as rollover effects, custom pull-down menus, and other navigation aids. They can also execute UI methods, for example, to validate a user's input in an HTML form. These script capabilities, while they enhance a user's interaction with individual Web pages, do not change the fundamental model in which application logic runs on the server and executes between Web pages after the user clicks. This behavior is said to be synchronous, that is, after each click the user waits while the server handles the input and the browser downloads a response page. In e-commerce, a typical user interaction involves a series of Web pages, which represent steps in a larger process that comprise a Web application
From Web Pages to Rich Internet Applications
Recently, Web developers have been evolving a new model--the Rich Internet Application (RIA), which is "a cross between Web applications and traditional desktop applications, transferring some of the processing to a
Web client and keeping (some of) the processing on the application server". As with most computing advances, several technologies are vying for acceptance as the de facto standard way to build RIAs. The main contenders are Adobe's Flash suite, Java applets, and the collection of Web technologies known as Ajax, a term coined in 2005 by Adaptive Path's Jesse James Garrett. Garrett explained that Ajax is "really several technologies, each flourishing in its own right, coming together in powerful new ways.
In practice, we can think of Ajax as a development concept or approach, as various technologies can
substitute for those specified by Garrett. Some developers even claim that "Flash is Ajax", and others
advocate using them together. See AFLAX. Complicating any analysis of RIA technology is the massive amount of hype surrounding both "Web 2.0" (a superset of RIA) and Ajax (a subset of RIA). Figure 1 illustrates these
relationships.
The Web was originally intended to help researchers share documents as static pages of linked text formatted in HTML. From there, Web pages quickly evolved to include complex structures of text and graphics, with plug-in programs to play audio and video files or to stream multimedia content. Web developers supplement the basic browser function of rendering HTML by invoking code (scripts) on the user's computer (the client). These scripts can create interface elements such as rollover effects, custom pull-down menus, and other navigation aids. They can also execute UI methods, for example, to validate a user's input in an HTML form. These script capabilities, while they enhance a user's interaction with individual Web pages, do not change the fundamental model in which application logic runs on the server and executes between Web pages after the user clicks. This behavior is said to be synchronous, that is, after each click the user waits while the server handles the input and the browser downloads a response page. In e-commerce, a typical user interaction involves a series of Web pages, which represent steps in a larger process that comprise a Web application
From Web Pages to Rich Internet Applications
Recently, Web developers have been evolving a new model--the Rich Internet Application (RIA), which is "a cross between Web applications and traditional desktop applications, transferring some of the processing to a
Web client and keeping (some of) the processing on the application server". As with most computing advances, several technologies are vying for acceptance as the de facto standard way to build RIAs. The main contenders are Adobe's Flash suite, Java applets, and the collection of Web technologies known as Ajax, a term coined in 2005 by Adaptive Path's Jesse James Garrett. Garrett explained that Ajax is "really several technologies, each flourishing in its own right, coming together in powerful new ways.
- Ajax incorporates:
- standards-based presentation using XHTML and CSS;
- dynamic display and interaction using the Document
Object Model; - data interchange and manipulation using XML and
XSLT; - asynchronous data retrieval using XMLHttpRequest;
- JavaScript binding everything together."
In practice, we can think of Ajax as a development concept or approach, as various technologies can
substitute for those specified by Garrett. Some developers even claim that "Flash is Ajax", and others
advocate using them together. See AFLAX. Complicating any analysis of RIA technology is the massive amount of hype surrounding both "Web 2.0" (a superset of RIA) and Ajax (a subset of RIA). Figure 1 illustrates these
relationships.
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