Pro JSF and Ajax

The differentiator that JSF brings, which other similar frameworks do not have, is the
backing of a standard specification (JSR-127). Because JSF is part of the J2EE standard specifi-
cation, it is a top priority for every major J2EE tools vendor in the market (including Oracle,
IBM, Borland, and Sun) to support it, which in turn will guarantee a wide adoption and good
tools support.
Most Web applications are stuck in the 1990s where too much effort was put into basic
plumbing and not into high-level components. Basically, when there is limited abstraction
or no abstraction over the markup, the development of Web applications becomes cumber-
some and hard to maintain. You can invest a lot of time into the application to make it rich
and interactive using various technologies from applets, plug-ins (Flex), Dynamic HTML
(DHTML), and JavaScript. Used together, these technologies can make up an interactive and
powerful Web application, but how do you maintain such an application? How do you reuse
what you have built?
Component Model
JSF brings to the table a best-of-breed J2EE framework. JSF is here to simplify life for applica-
tion developers, making it possible for them to focus on the view without needing to know the
underlying markup or scripts. They will see an improvement in productivity with JSF using
UI components that hide most of the grunt work of integrating richer functionality into Web
applications. The goal is to provide an easy way to construct UIs from a set of reusable UI
components.
These reusable components come in various shapes with different functionality, from
layout components (such as the layout of an entire page) to simple buttons. Application devel-
opers can use these components to construct a page and nest UI components within each
other to get the desired effect; for example, nesting text fields and buttons within a row layout
component will render the nested UI components in a single row on the client. This structure
of nested components is often referred to as a parent-to-child relationship and visualized as a
UI component hierarchy. This UI component hierarchy represents a JSF page description at
runtime.
Navigation Model
JSF provides a declarative navigation model, which allows application developers to set
navigation rules to define the navigation from one view to another in a Web application. Navi-
gation rules in JSF are defined inside the JSF configuration file, faces-config.xml, and are
page-based. Code Sample 1-1 shows a navigation rule configured in faces-config.xml.
C H A P T E R 1
s
T H E F O U N D AT I O N O F J S F : C O M P O N E N T S
8