PanelGrid Example with JSF 2.0

Thodoris BaisApril 19th, 2014Last Updated: May 9th, 2019

0 177 2 minutes read

Today we ‘re gonna talk about table formatting in JSF.

Remember yourself on your very first steps to Web Development, how easy was it to manipulate a table with raw HTML? You had to follow a strict writing with a bunch of specific HTML tags, in order to get what you wanted to.

JSF is here to make our lives easier, in table manipulation, too, so let’s take a look at a comparative initial example, between HTML and JSF:

HTML

<table>
	<tbody>
		<tr>
			<td>Please enter a number:</td>		
			<td>
				<h:inputText id="number" value="#{sample_bean.number}" 
					size="20" required="true"
					label="Number" >
					<f:convertNumber />
				</h:inputText>
			</td>
			<td><h:message for="number" style="color:red" /></td>
		</tr>
	</tbody>
</table>

Piece of cake, but still a waste of time. That’s the corresponding format of the above table in JSF:

<h:panelGrid columns="3">
	Please enter a number: 
 
	<h:inputText id="number" value="#{sample_bean.number}" 
		size="20" required="true"
		label="Number" >
		<f:convertNumber />
	</h:inputText>
 
	<h:message for="number" style="color:red" />
</h:panelGrid>

Ok, pretty easier with JSF, but what’s the functionality of <f:convertNumber /> ?

Generally, the fore-mentioned tag creates a number formatting converter and associates it with the nearest parent UIComponent; for more information, please refer here.

The final goal of this tutorial, is to transfer the number inserted from the user, to another page, after validating that it actually was a number (and not a string, for example). So, we ‘re here using the <f:convertNumber /> for validation purpose.

The Example

Here is a demonstration JSF app, using panelGrid for the elements’ proper layout.

1. The Managed Bean

package com.javacodegeeks.jsf.panelgrid;

import java.io.Serializable;

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

@ManagedBean(name="sample_bean")
@SessionScoped
public class SampleBean implements Serializable{

	int number;

	public int getNumber() {
		return number;
	}

	public void setNumber(int number) {
		this.number = number;
	}
}

2. The JSF Pages

index.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" 
      xmlns:c="http://java.sun.com/jsp/jstl/core" >
 
    <h:head>
    	<title>JSF PanelGrid</title>
    </h:head>
    
    <h:body>
    	<h1>JSF 2.2 PanelGrid Example</h1>
    	
    	<h:form>
    		<h:panelGrid columns="3">
    			Please enter a number:
    			<h:inputText id="number"
    						 value="#{sample_bean.number}"
    						 size="15" required="true"
    						 label="Number" >
    						<f:convertNumber />
    			</h:inputText>
    			<h:message for="number" style="color:red" />
    		</h:panelGrid>
    		<h:commandButton value="Submit" action="result"/>
    	</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"
      xmlns:f="http://java.sun.com/jsf/core"
      xmlns:c="http://java.sun.com/jsp/jstl/core"
      >
    
    <h:head>
    	<title>JSF PanelGrid</title>
    </h:head>
    
    <h:body>
     	<h1>JSF 2.2 PanelGrid Example</h1>
			Number : <h:outputText value="#{sample_bean.number}" />
  </h:body>
</html>

3. The Demo

Let’s first insert a string, just to see our app’s exception handling; we ‘ll then insert a number (75 in our case), to conform with the success path.