<f:selectItems
value=”#{backingBean.songList}”/>
</h:selectOneMenu>
</br>
<h:outputText id=”result”
value=”#{backingBean.songDetail}”/>
</br></br>
<h:selectOneRadio id=”catId”
value=”#{backingBean.category}”
immediate=”true” onclick=”submit()”
valueChangeListener=
”#{backingBean.processValueChange2}”>
<f:selectItems
value=”#{backingBean.categories}”/>
</h:selectOneRadio>
<h:selectOneListbox id=”subcategory”
value=”#{backingBean.subCategory}”
binding=”#{backingBean.subCategoryList}”
rendered = “false”>
<f:selectItems
value=”#{backingBean.subCategories}”/>
</h:selectOneListbox>
</br></br>
<h:commandButton id=”cb” value=”Show
All Selected” immediate=”true”
actionListener=
”#{backingBean.processActionShow}”/>
</br>
<h:outputText id=”showValue”
binding=”#{backingBean.showAllSelected}”
rendered=”true”/>
</h:form>
</f:view>
</body>
</html>

In the above code, you can see that immediate attribute is set to “true” i.e. handle the events for the component in the apply request values phase rather than the invoke application phase. JavaScript code is used to process the value change event immediately when the user makes
a change. Component generating action event doesn’t require this support so there is no need to write JavaScript code to submit the component for processing.

The event handler methods:

The value change event handler method for the

component used for selection of the song is processValueChange1() which has been mentioned in the attribute valueChangeListener.

valueChangeListener=
”#{backingBean.processValueChange1}”

The value change event handler method for the component used for selection of category is processValueChange2() which has been mentioned in the attribute

valueChangeListener.

valueChangeListener=
”#{backingBean.processValueChange2}”>

The action event handler method for the component used to show all selected items is processActionShow() which has been mentioned in the attribute actionListener.

actionListener=”#{backingBean.processActionShow}”

Backing Bean:

Backing bean named “Bean.java” implements event handler methods. It’s code is given below:

Bean.java

package javajazzup;
import java.util.*;
import javax.faces.component.*;
import
javax.faces.component.html.HtmlOutputText;
import
javax.faces.component.html.HtmlSelectOneListbox;
import javax.faces.event.ActionEvent;
import javax.faces.event.ValueChangeEvent;
import javax.faces.context.FacesContext;
import javax.faces.model.SelectItem;
public class Bean{
// Stores song titles
ArrayList songList;