JavaServer Faces

Developing Components and Integration Code

The component writer develops all application-specific Java code needed for the user interface, ranging from simple classes that tie the user interface to the application backend code developed by the application developer to custom user interface components when the ones provided by JSF aren’t sufficient.

Figure 2-2 shows the main classes and interfaces used by the newsletter application.

Figure 2-2. JSF component-related classes and the Subscriber application class

You probably recognize the Subscriber class from the previous section. The component writer develops the SubscriberHandler class, as shown in this section. All the other classes in Figure 2-2 are provided by the JSF implementation.

The UIComponentBase class is the base class for all JSF UI components. Subclasses represent specific interface elements, such as text fields, links and buttons, labels, menus and selection lists. JSF includes a set of component classes that can be used right out of the box, such as the ones shown in Figure 2-2, but a component writer can also implement custom components if needed. The UIInput class represents an input field and lets you bind the component to an application model through a value binding. When a component is rendered, it pulls its value from the application model object based on this value binding. Similarly, when an input component processes ...