JSF 2 PreRenderViewEvent example

In JSF 2.0, you can attach a javax.faces.event.PreRenderViewEvent system event to perform custom task before a view root (JSF page) is display.

Let see a complete PreRenderViewEvent example below :

1. Managed Bean

Create a normal bean, contains a method signature “public void method-name(ComponentSystemEvent event)“, later you will ask listener to call this method.

In this method, it validate “role” in the current session, if the role is NOT equal to “admin“, then navigate it to outcome “access-denied“.

package com.mkyong;
 
import javax.faces.application.ConfigurableNavigationHandler;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
import javax.faces.context.FacesContext;
import javax.faces.event.ComponentSystemEvent;
 
@ManagedBean(name="user")
@SessionScoped
public class UserBean{
 
  public void isAdmin(ComponentSystemEvent event){
 
	FacesContext fc = FacesContext.getCurrentInstance();
 
	if (!"admin".equals(fc.getExternalContext().getSessionMap().get("role"))){
 
		ConfigurableNavigationHandler nav 
		   = (ConfigurableNavigationHandler) 
			fc.getApplication().getNavigationHandler();
 
		nav.performNavigation("access-denied");
	}		
  }	
}

2. JSF Page

Now, you use f:event tag to attach “preRenderView” system event to “default.xhtml” page.

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"
      >
 
 	<f:event listener="#{user.isAdmin}" type="preRenderView" />
 
	<h:body>
 
	    <h1>JSF 2 protected page example</h1>
 
	</h:body>
 
</html>

access-denied.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>Access Denied!</h1>
 
    </h:body>
 
</html>

3. Demo

Access this page “default.xhtml“, since there is no “role” value in session object, so JSF will navigate to another page “access-denied.xhtml“.

jsf2-PreRenderViewEvent-example

Download Source Code

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

Reference

  1. JSF 2 PreRenderViewEvent JavaDoc
Tags :

About the Author

mkyong
Founder of Mkyong.com and HostingCompass.com, love Java and open source stuff. Follow him on Twitter, or befriend him on Facebook or Google Plus. If you like my tutorials, consider make a donation to these charities.

Comments

  • Pingback: car parking()

  • Pingback: Instagram likes kopen()

  • Pingback: 3gp mobile porn()

  • Pingback: car parking()

  • Pingback: Ginormous juggs girlfriend veronica super-naughty anal invasion out and caught on()

  • Pingback: Blue Coaster33()

  • NaveenReddy Bommu

    Thank you very much. This is cool. Nice tutorial.

  • Pingback: PhaseListener: JSF 1.2 Alternative to PreRenderViewEvent()

  • MarkB

    Just wondering, does this work with @Autowired?

    If I have a Bean

    @Autowired
    UserService userService;

    will my Service bean be init, or will it still be null (as it is when using @PostConstruct)

    MB

    • Mark

      Yes it does!

      This is exactly what I have been looking for.

      PS: Another good trick
      wrap your preRenderView method with this
      if (!FacesContext.getCurrentInstance().isPostback()) {

      }

      and the code wont be ran if you are posting back from a h:commandButton or something.

  • Raffaele

    Hi,
    there is a way for verify permission of user that is logged in application? I want to do this on every single action/actionListener calls.
    For example, I want check permissions of an user that throw an event (submit or f:ajax event) client side and, before call the corresponding Action/Action Listener server side, verify if user have previleges for call it. I don’t want a global way to do this.

  • khocef

    it wasn’t working for me but i add and it worked

    &lt;f:metadata&gt;
    	&lt;f:event listener=&quot;#{navigationBean.isConnected}&quot; type=&quot;preRenderView&quot; /&gt;
    &lt;/f:metadata&gt;
  • Fayyaz Ali

    Hello,

    when using preRenderView with redirect, the page returns jsf code not html;

    below is my code;

     
    &lt;f:event type=&quot;preRenderView&quot; listener=&quot;#{usersController.checkAuthentication()}&quot; /&gt;
    public void checkAuthentication(){
            if(!getisloggedin()){        
                try {
                        FacesContext.getCurrentInstance().getExternalContext().redirect(&quot;Login.xhtml&quot;);
    } catch (Exception e) {
                        JsfUtil.addSuccessMessage(&quot;Error occured while redirecting.&quot;);
                    }
            }
    }

    the above code will return the actual jsf code of Login.xhtml in browser.

  • Pingback: JSF 2.0 call server side method on page load | PHP Developer Resource()

  • Pingback: JSF 2.0 Tutorial « java config()

  • kayo

    Not working when accessing directly from
    URL: http://localhost:8080/JavaServerFaces/default.xhtml

    JSF: MyFaces 2.1.1

    • jaff

      you should not access the xhtml pages directly you access like this then there wont be a problem “default.jsf”