Showing posts with label listbox. Show all posts
Showing posts with label listbox. Show all posts

Wednesday, 25 September 2013

JSF2 Listbox Example

// siddhu vydyabhushana // 1 comment
In JSF, <h:selectOneListbox /> tag is used to render a single select listbox – HTML select element with “size” attribute.
//JSF...
<h:selectOneListbox value="#{user.favYear1}">
   	<f:selectItem itemValue="2000" itemLabel="Year1 - 2000" />
   	<f:selectItem itemValue="2010" itemLabel="Year1 - 2010" />
   	<f:selectItem itemValue="2020" itemLabel="Year1 - 2020" />
</h:selectOneListbox>
 
//HTML output...
<select name="j_idt6:j_idt8" size="3">	
	<option value="2000">Year1 - 2000</option> 
	<option value="2010">Year1 - 2010</option> 
	<option value="2020">Year1 - 2020</option> 
</select>

h:selectOneListbox example

A JSF 2.0 example to show the use of “h:selectOneListbox” tag to render a single select listbox, and populate the data in 3 different ways :
  1. Hardcoded value in “f:selectItem” tag.
  2. Generate values with a Map and put it into “f:selectItems” tag.
  3. Generate values with an Object array and put it into “f:selectItems” tag, then represent the value with “var” attribute.

1. Backing Bean

A backing bean to hold and generate data for listbox values.
package com.mkyong;
 
import java.io.Serializable;
import java.util.LinkedHashMap;
import java.util.Map;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
 
@ManagedBean(name="user")
@SessionScoped
public class UserBean implements Serializable{
 
	public String favYear1;
	public String favYear2;
	public String favYear3;
 
	//getter and setter methods
 
	//Generated by Map
	private static Map<String,Object> year2Value;
	static{
		year2Value = new LinkedHashMap<String,Object>();
		year2Value.put("Year2 - 2000", "2000"); //label, value
		year2Value.put("Year2 - 2010", "2010");
		year2Value.put("Year2 - 2020", "2020");
	}
 
	public Map<String,Object> getFavYear2Value() {
		return year2Value;
	}
 
	//Generated by Object array
	public static class Year{
		public String yearLabel;
		public String yearValue;
 
		public Year(String yearLabel, String yearValue){
			this.yearLabel = yearLabel;
			this.yearValue = yearValue;
		}
 
		public String getYearLabel(){
			return yearLabel;
		}
 
		public String getYearValue(){
			return yearValue;
		}
 
	}
 
	public Year[] year3List;
 
	public Year[] getFavYear3Value() {
 
		year3List = new Year[3];
		year3List[0] = new Year("Year3 - 2000", "2000");
		year3List[1] = new Year("Year3 - 2010", "2010");
		year3List[2] = new Year("Year3 - 2020", "2020");
 
		return year3List;
	}
 
}

2. JSF Page

A JSF page to demonstrate the use “h:selectOneListbox” tag.
<?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 listbox example</h1>
    	<h:form>
 
	        1. Hard-coded with "f:selectItem" : 
   		<h:selectOneListbox value="#{user.favYear1}">
   			<f:selectItem itemValue="2000" itemLabel="Year1 - 2000" />
   			<f:selectItem itemValue="2010" itemLabel="Year1 - 2010" />
   			<f:selectItem itemValue="2020" itemLabel="Year1 - 2020" />
   		</h:selectOneListbox>
 
   		<br />
 
	        2. Generated by Map :
   		<h:selectOneListbox value="#{user.favYear2}">
   			<f:selectItems value="#{user.favYear2Value}" />
   		</h:selectOneListbox>
 
	        <br />
 
	        3. Generated by Object array and iterate with var :
   		<h:selectOneListbox value="#{user.favYear3}">
   			<f:selectItems value="#{user.favYear3Value}" var="y"
   			itemLabel="#{y.yearLabel}" itemValue="#{y.yearValue}" />
   		</h:selectOneListbox>
 
	        <br />
 
    	        <h:commandButton value="Submit" action="result" />
	        <h:commandButton value="Reset" type="reset" />
 
    	</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 listbox example</h1>
 
    	<h2>result.xhtml</h2>
 
    	<ol>
    		<li>user.favYear1 : #{user.favYear1}</li>
    		<li>user.favYear2 : #{user.favYear2}</li>
    		<li>user.favYear3 : #{user.favYear3}</li>
    	</ol>
    </h:body>
 
</html>

3. Demo

jsf2-listbox-example-1
When “submit” button is clicked, link to “result.xhtml” page and display the submitted listbox values.
jsf2-listbox-example-2

How to pre-select a listbox value?

The value of “f:selectItems” tag is selected if it matched to the “value” of “h:selectOneListbox” tag. In above example, if you set favYear1 property to “2010″ :
@ManagedBean(name="user")
@SessionScoped
public class UserBean{
 
	public String favYear1 = "2010";
 
	//...
The “favYear1″ listbox, value “2010″ is selected by default.

Download Source Code

Download It – JSF-2-Listbox-Example.zip (10KB)
 
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JSF 2.0 Multiple select Listbox Example

// siddhu vydyabhushana // 1 comment
In JSF, <h:selectManyListbox /> tag is used to render a multiple select listbox – HTML select element with “multiple” and “size” attribute.
//JSF...
<h:selectManyListbox value="#{user.favFood1}">
   	<f:selectItem itemValue="Fry Checken" itemLabel="Food1 - Fry Checken" />
   	<f:selectItem itemValue="Tomyam Soup" itemLabel="Food1 - Tomyam Soup" />
   	<f:selectItem itemValue="Mixed Rice" itemLabel="Food1 - Mixed Rice" />
</h:selectManyListbox>
 
//HTML output...
<select name="j_idt6:j_idt8" multiple="multiple" size="3">	
	<option value="Fry Checken">Food1 - Fry Checken</option> 
	<option value="Tomyam Soup">Food1 - Tomyam Soup</option> 
	<option value="Mixed Rice">Food1 - Mixed Rice</option> 
</select>

h:selectManyListbox example

A JSF 2.0 example to show the use of “h:selectManyListbox” tag to render multiple select listbox, and populate the data in 3 different ways :
  1. Hardcoded value in “f:selectItem” tag.
  2. Generate values with a Map and put it into “f:selectItems” tag.
  3. Generate values with an Object array and put it into “f:selectItems” tag, then represent the value with “var” attribute.

1. Backing Bean

A backing bean to hold and generate data for the multiple select listbox values. The property to hold the multi-selected listbox value, must be a type of Collection or Array; Otherwise it will hits the following error message
WARNING: Target model Type is no a Collection or Array
javax.faces.FacesException: Target model Type is no a Collection or Array
package com.mkyong;
 
import java.io.Serializable;
import java.util.Arrays;
import java.util.LinkedHashMap;
import java.util.Map;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
 
@ManagedBean(name="user")
@SessionScoped
public class UserBean implements Serializable{
 
	public String[] favFood1;
	public String[] favFood2;
	public String[] favFood3;
 
	//getter and setter methods...
 
	public String getFavFood1InString() {
		return Arrays.toString(favFood1);
	}
 
	public String getFavFood2InString() {
		return Arrays.toString(favFood2);
	}
 
	public String getFavFood3InString() {
		return Arrays.toString(favFood3);
	}
 
	//Generated by Map
	private static Map<String,Object> food2Value;
	static{
		food2Value = new LinkedHashMap<String,Object>();
		food2Value.put("Food2 - Fry Checken", "Fry Checken"); //label, value
		food2Value.put("Food2 - Tomyam Soup", "Tomyam Soup");
		food2Value.put("Food2 - Mixed Rice", "Mixed Rice");
	}
 
	public Map<String,Object> getFavFood2Value() {
		return food2Value;
	}
 
	//Generated by Object array
	public static class Food{
		public String foodLabel;
		public String foodValue;
 
		public Food(String foodLabel, String foodValue){
			this.foodLabel = foodLabel;
			this.foodValue = foodValue;
		}
 
		public String getFoodLabel(){
			return foodLabel;
		}
 
		public String getFoodValue(){
			return foodValue;
		}
 
	}
 
	public Food[] food3List;
 
	public Food[] getFavFood3Value() {
 
		food3List = new Food[3];
		food3List[0] = new Food("Food3 - Fry Checken", "Fry Checken");
		food3List[1] = new Food("Food3 - Tomyam Soup", "Tomyam Soup");
		food3List[2] = new Food("Food3 - Mixed Rice", "Mixed Rice");
 
		return food3List;
	}
 
}

2. JSF Page

A JSF page to demonstrate the use “h:selectManyListbox” tag.
<?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 multi-select listbox example</h1>
    	<h:form>
 
	    1. Hard-coded with "f:selectItem" : 
   		<h:selectManyListbox value="#{user.favFood1}">
   			<f:selectItem itemValue="Fry Checken" itemLabel="Food1 - Fry Checken" />
   			<f:selectItem itemValue="Tomyam Soup" itemLabel="Food1 - Tomyam Soup" />
   			<f:selectItem itemValue="Mixed Rice" itemLabel="Food1 - Mixed Rice" />
   		</h:selectManyListbox>
 
		<br /><br />
 
	    2. Generated by Map :
   		<h:selectManyListbox value="#{user.favFood2}">
   			<f:selectItems value="#{user.favFood2Value}" />
   		</h:selectManyListbox>
 
	    <br /><br />
 
	    3. Generated by Object array and iterate with var :
   		<h:selectManyListbox value="#{user.favFood3}">
   			<f:selectItems value="#{user.favFood3Value}" var="f"
   			itemLabel="#{f.foodLabel}" itemValue="#{f.foodValue}" />
   		</h:selectManyListbox>
 
	    <br /><br />
 
    	    <h:commandButton value="Submit" action="result" />
	    <h:commandButton value="Reset" type="reset" />
 
    	</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 multi-select listbox example</h1>
 
    	<h2>result.xhtml</h2>
 
    	<ol>
    		<li>user.favFood1 : #{user.favFood1InString}</li>
    		<li>user.favFood2 : #{user.favFood2InString}</li>
    		<li>user.favFood3 : #{user.favFood3InString}</li>
    	</ol>
    </h:body>
 
</html>

3. Demo

jsf2-multi-select-listbox-example-1
When “submit” button is clicked, link to “result.xhtml” page and display the submitted multi-selected listbox values.
jsf2-multi-select-listbox-example-2

How to pre-select multiple listbox values ?

The value of “f:selectItems” tag is selected if it matched to the “value” of “h:selectManyListbox” tag. In above example, if you set favFood1 property to “Fry Checken” and “Tomyam Soup” :
@ManagedBean(name="user")
@SessionScoped
public class UserBean{
 
	public String[] favFood1 = {"Fry Checken", "Tomyam Soup"};
 
	//...
The “favFood1″ listbox values, “Fry Checken” and “Tomyam Soup” are selected by default.

Download Source Code

 
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