1) Introduction
In this article, let us see the different types of Navigation mechanisms available in JSF. The JSF Navigation Model is both declarative and programmatic, i,e, Navigation can be configured either statically in the deployment time or dynamically during the run-time of a Web Application. We will see how to configure such navigation models in a Web Application with code snippets. This article is not an introductory article for JSF and hence readers with no or little JSF knowledge are advised to go through the Introductory article on JSF in javabeat.
2) Navigation
Navigation happens in a Web Application when a user tries to switch from one page to another page either by clicking a button after entering some input values, clicking a hyperlink, or directly entering the target URL of the Web Application in a browser. Whatever be the case, the next page to be displayed or the response for the current page has to be handled by the Web Application. Take the case of Java Servlets Technology. When a Web Browser invokes the Servlet by typing the Servlet URL in the Address bar, the method doGet() (the default method) will get invoked and the response is shown in the Browser window.
Imagine that the response delivered from the Servlet is prompting the user to enter some other input forcing the current page to navigate to the next output page. Here the Navigation mechanism is totally handled only by the Web Application. The Navigation Handling Servlet should look for the current display page, then depending on the output of the current page the next page (or the next view) to be displayed is selected. The output of the current page may logically fall into success, failure, need more input, etc and all these cases have to be handled separately.
The designers of JSF soon recognized the need for Navigation handling since it is almost common in all Web Applications. The Navigation model in JSF is highly configurable and it is very simple to understand and use. The subsequent sections will detail the different types of Navigation models along with code samples.
3) Types of Navigation
JSF supports two kinds of Navigation models which are,
- Static Navigation
- Dynamic Navigation
Static Navigation is recommended when the output of one page is known well in Advance and it is always easier to predict the output of the current page. Whereas, it is better to use Dynamic Navigation when the output of the current page is highly unpredictable and the output depends mainly on the execution of some Business logic.
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