JavaServer Faces

Moving Between JSF Views

In addition to the main functionality, the sample application lets the user edit preferences through a separate set of screens. The application ignores all preference settings, but looking at how these preferences screens are implemented illustrates how JSF navigation works.

On a regular web site, links are used to navigate between different pages. A JSF web application may also use links, and there’s a special action element that you should use to add a link to a page. It’s the <h:outputLink> action element, and here’s how it’s used in the sample application’s menu area:

...
  <h:outputLink value="prefUser.faces">
    <h:outputText value="Preferences" />
  </h:outputLink>
...

The action uses the value attribute to render the corresponding HTML <a> element’s href value, with an encoded session ID if needed for cookie-less session tracking. Nested <f:param> action elements can be used to add query string parameters (see Appendix A for details). The link text is taken from the value of one or more child components, such as the output component represented by the <h:outputText> element in this example. Figure 9-1 shows the menu area with the generated link in a browser.

Figure 9-1. Menu area with link to the first preferences screen

Navigation through a direct link is simple and sufficient in many cases, but not when user input must be processed before moving on to the next ...