JSF - f:param


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f:param tag provides the options to pass parameters to a component or pass request parameters.

JSF Tag

Pass parameter to a UI component

<h:outputFormat value = "Hello {0}!.">     
   <f:param value = "World" /> 
</h:outputFormat>

Pass request parameter

<h:commandButton id = "submit"  
   value = "Show Message" action = "#{userData.showResult}"> 
   <f:param name = "username" value = "JSF 2.0 User" /> 
</h:commandButton> 

Tag Attributes

S.No Attribute & Description
1

id

Identifier for a component

2

binding

Reference to the component that can be used in a backing bean

3

name

An optional name for this parameter component

4

value

The value stored in this component

Example Application

Let us create a test JSF application to test the above tag.

Step Description
1 Create a project with a name helloworld under a package com.tutorialspoint.test as explained in the JSF - First Application chapter.
2 Modify home.xhtml as explained below. Keep rest of the files unchanged.
3 Create result.xhtml in the webapps directory as explained below.
4 Create UserData.java as a managed bean under package com.tutorialspoint.test as explained below.
5 Compile and run the application to make sure business logic is working as per the requirements.
6 Finally, build the application in the form of war file and deploy it in Apache Tomcat Webserver.
7 Launch your web application using appropriate URL as explained below in the last step.

UserData.java

package com.tutorialspoint.test;

import java.io.Serializable;

import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;

@ManagedBean(name = "userData", eager = true)
@SessionScoped
public class UserData implements Serializable {
   private static final long serialVersionUID = 1L;
   public String data = "1";

   public String getData() {
      return data;
   }

   public void setData(String data) {
      this.data = data;
   }

   public String showResult() {
      FacesContext fc = FacesContext.getCurrentInstance();
      Map<String,String> params = 
         fc.getExternalContext().getRequestParameterMap();
      data =  params.get("username"); 
      return "result";
   }
}

home.xhtml

<!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">
   <head>
      <title>JSF Tutorial!</title>
   </head>
   
   <body>
      <h2>f:param example</h2>
      <hr />
      
      <h:form>
         <h:outputFormat value = "Hello {0}!.">
            <f:param value = "World" />
         </h:outputFormat>
         <br/>
         
         <h:commandButton id = "submit" 
            value = "Show Message" action = "#{userData.showResult}">
            <f:param name = "username" value = "JSF 2.0 User" />
         </h:commandButton>
      </h:form>
   
   </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:f = "http://java.sun.com/jsf/core"    
   xmlns:h = "http://java.sun.com/jsf/html"
   xmlns:ui = "http://java.sun.com/jsf/facelets">
   
   <head>
      <title>JSF Tutorial!</title>
   </head>
   
   <h:body>
      <h2>Result</h2>
      <hr />
      #{userData.data}
   </h:body>
</html>  

Once you are ready with all the changes done, let us compile and run the application as we did in JSF - First Application chapter. If everything is fine with your application, this will produce the following result.

JSF h:param

Press Show Message button and you'll see the following result.

JSF h:param1
jsf_basic_tags.htm

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