Chapter 1 Introduction to ICEfaces

Chapter 1 Introduction to ICEfaces

ICEfaces® is the industry's leading open-source, standards-compliant Ajax-based solution for rapidly creating enterprise grade, pure-Java rich web applications.

ICEfaces provides a rich web presentation environment for JavaServer Faces (JSF) applications that enhances the standard JSF framework and lifecycle with Ajax-based interactive features. ICEfaces replaces the standard HTML-based JSF renderers with Direct-to-DOM (D2D) renderers, and introduces a lightweight Ajax bridge to deliver presentation changes to the client browser and to communicate user interaction events back to the server-resident JSF application. Additionally, ICEfaces provides an extensive Ajax-enabled component suite that facilitates rapid development of rich interactive web-based applications. The basic architecture of an ICEfaces-enabled application is shown in Figure 1 below.

Figure 1 ICEfaces-enabled JSF Application

The rich web presentation environment enabled with ICEfaces provides the following features:

Smooth, incremental page updates that do not require a full page refresh to achieve presentation changes in the application. Only elements of the presentation that have changed are updated during the render phase.
User context preservation during page update, including scroll position and input focus. Presentation updates do not interfere with the user's ongoing interaction with the application.

These enhanced presentation features of ICEfaces are completely transparent from the application development perspective. Any JSF application that is ICEfaces-enabled will benefit.

Beyond these transparent presentation features, ICEfaces introduces additional rich presentation features that the JSF developer can leverage to further enhance the user experience. Specifically, the developer can incorporate these features:

Intelligent form processing through a technique called Partial Submit. Partial Submit automatically submits a form for processing based on some user-initiated event, such as tabbing between fields in a form. The automatic submission limits form processing to the single control that has been altered, but allows the application lifecycle to execute in response to that change. This means that the application developer can introduce intelligent form processing logic that reacts instantaneously to user interactions with the form.
Server-initiated asynchronous presentation update (Ajax Push). Standard JSF applications can only deliver presentation changes in response to a user-initiated event, typically some type of form submit. ICEfaces introduces a server-initiated rendering that enables the server-resident application logic to push presentation changes to the client browser in response to changes in the application state. This enables application developers to design systems that deliver data to the user in a near-real-time asynchronous fashion.