What's Facelets ?
Facelets is a powerful but lightweight page declaration language that is used to build JavaServer Faces views using HTML style templates and to build component trees.
Facelets features include the following:
Use of XHTML for creating web pages
Support for Facelets Tag libraries in addition to JavaServer Faces and JSTL tag libraries
Support for unified expression language
Templating for components and pages
Web Pages
Facelets views are usually created as XHTML pages. JavaServer Faces implementations support XHTML pages created in conformance with the XHTML Transitional DTD, as listed at http://www.w3.org/TR/xhtml1/#a_dtd_XHTML-1.0-Transitional.
By convention, web pages built with XHTML have an .xhtml extension.
Tag Library Support
JavaServer Faces technology supports different tag libraries to add components to a web page. To support the JavaServer Faces tag library mechanism, Facelets uses XML namespace declarations.
The following table Table 5-1 lists the tag libraries supported by Facelets.
Table 5-1 Tag Libraries Supported by Facelets
Tag Library |
URI |
Prefix |
Example |
Contents |
|---|---|---|---|---|
JavaServer Faces Facelets Tag Library |
http://java.sun.com/jsf/facelets |
ui: |
ui:component ui:insert |
Tags for templating |
JavaServer Faces HTML Tag Library |
http://java.sun.com/jsf/html |
h: |
h:head h:body h:outputText h:inputText |
JavaServer Faces component tags for all UIComponents. |
JavaServer Faces Core Tag Library |
http://java.sun.com/jsf/core |
f: |
f:actionListener f:attribute |
Tags for JavaServer Faces custom actions that are independent of any particular RenderKit. |
JSTL Core Tag Library |
http://java.sun.com/jsp/jstl/core |
c: |
c:forEach c:catch |
JSTL 1.1 Core Tags |
JSTL Functions Tag Library |
http://java.sun.com/jsp/jstl/functions |
fn: |
fn:toUpperCase fn:toLowerCase |
JSTL 1.1 Functions Tags |
In addition, Facelets also supports tags for composite components for which you can declare custom prefixes. For more information on composite components, see Composite Components.
Unified Expression Language Support
Based on the JavaServer Faces support for unified expression language (EL) syntax defined by JSP 2.1, Facelets uses EL expressions to reference properties and methods of backing beans. EL expressions can be used to bind component objects or values to managed-bean methods or managed-bean properties. For more information on using EL expressions, see Using the EL to Reference Backing Beans.