Practical RichFaces, Second Edition

CHAPTER 1 THE BASICS
JSF Is Very Extendable
The extensibility feature is probably most responsible for making JSF a popular tool for building web
applications. From the beginning, JSF was designed to be extended. Through standards, JSF allows you
to extend the framework with new features and more advanced functionality. You are getting new
functionality, but you are doing it in a standard and accepted way. One area that benefits most from this
is the rich UI component ecosystem, which includes RichFaces. This eco-system is not limited to UI
components—custom converters, validators, view handlers, and other extensions are created as well.
The Most Important JSF Features
JSF offers a long list of features. However, since this is not a dedicated JSF book, we will briefly cover the
three most important features: user interface components, events, and the new Ajax functionality in JSF
2. If you feel you need to review your JSF skills, we recommend the following two books: Core JavaServer
Faces, Third Edition by David Geary and Cay Horstmann (Prentice Hall, 2010) and JavaServer Faces 2.0,
The Complete Reference by Ed Burns and Chris Schalk (McGraw-Hill, 2009).
Tip Two really great places to start learning JSF are http://javaserverfaces.org and
http://jsfcentral.com.
User Interface Components
UI components are the main feature of the JSF framework. JSF ships with about 30 ready-to-use user
interface components. Usually referred to as standard components, they provide basic user interface
widgets for input, output, commands (buttons and links), labels, and layout, as well as simple controls to
display tabular data. A number of utility components such as loading styles, scripts, and HTML page
sections (head, body) are available as well.
All JSF web applications are built out of components. A JSF UI component is a server-side Java
object capable of processing input, firing actions, and rendering content. Component hierarchy is what
JSF deals with. And tags are used for building that component tree. A JSF component can be as simple as
an input field or as sophisticated as a tabbed panel or tree. For example, the following tag represents an
input component:
This is an input component that is bound (connected) to some Java object. You would place this tag
on a JSF page instead of directly writing HTML code. The component behind the tag knows how to
generate all the necessary and correct HTML, CSS, and JavaScript. Tags represent the server-side UI
components and are used to build the JSF component tree shown in Figure 1-4.
Component Rendering
The JSF framework separates a component from the way it is presented (encoding) and the way input is
processed (decoding). The appearance of the component can be easily varied for the type of display
device available (for example, a mobile phone). For this book, you’ll work only with the HTML rendering
kit that JSF provides out of the box.