In JSF, “f:attribute” tag allow you to pass a attribute value to a component, or a parameter to a component via action listener. For example,

1. Assign a attribute value to a component.

<h:commandButton">
    <f:attribute name="value" value="Click Me" />				
</h:commandButton>
 
//is equal to 
 
<h:commandButton value="Click Me" />

2. Assign parameter to a component and get it back via action listener.

<h:commandButton actionListener="#{user.attrListener}" >
    <f:attribute name="username" value="mkyong" />
</h:commandButton>
@ManagedBean(name="user")
@SessionScoped
public class UserBean{
 
  //action listener event
  public void attrListener(ActionEvent event){
 
	nickname = (String)event.getComponent().getAttributes().get("username");
 
  }

JSF f:attribute example

Ok, let’s see a full example in JSF 2.0.

1. Managed Bean

A managed bean named “user”, with an action listener method.

package com.mkyong;
 
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
import javax.faces.event.ActionEvent;
 
@ManagedBean(name="user")
@SessionScoped
public class UserBean{
 
	public String nickname;
 
	//action listener event
	public void attrListener(ActionEvent event){
 
		nickname = (String)event.getComponent().getAttributes().get("username");
 
	}
 
	public String outcome(){
		return "result";
	}
 
	public String getNickname() {
		return nickname;
	}
 
	public void setNickname(String nickname) {
		this.nickname = nickname;
	}
}

2. JSF Page

JSF pages to show the use of “f:attribute” tag to pass a attribute value to a “h:commandButton” component.

default.xhtml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"   
      xmlns:h="http://java.sun.com/jsf/html"
      xmlns:f="http://java.sun.com/jsf/core"
      >
 
    <h:body>
 
    	<h1>JSF 2 attribute example</h1>
 
	<h:form id="form">
 
	  <h:commandButton action="#{user.outcome}"
			actionListener="#{user.attrListener}" >
 
		<f:attribute name="username" value="mkyong" />
		<f:attribute name="value" value="Click Me" />
 
	  </h:commandButton>
 
	</h:form>
 
    </h:body>
</html>

result.xhtml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"   
      xmlns:h="http://java.sun.com/jsf/html"
      >
 
    <h:body>
 
    	<h1>JSF 2 attribute example</h1>
 
		#{user.nickname}
 
    </h:body>
 
</html>

3. Demo

Here’s the result.

jsf2-attribute-example-1
jsf2-attribute-example-2

Download Source Code

Download It – JSF-2-Attribute-Example.zip (10KB)

Reference

  1. JSF 2 attribute JavaDoc
  2. JSF 2 action listener example
Note : You can find more similar articles at - JSF 2 Tutorials
You might also like this tutorials :
JAX-WS Tutorials
Maven Tutorials
Java MongoDB Tutorials
Struts 2.x Tutorials
Apache Wicket Tutorials