Trouble with Primefaces 3.0.M2 SelectOneMenu Ajax behavior
I am having trouble with implementing two SelectOneMenu controls, where data in the second one depends on the selection made in the first. This example on the primeFaces showcase is almost the same as what I want to implement: http://www.primefaces.org/showcase-labs/ui/pprSelect.jsf
except that I have to get the data from a database.
The above example is working correctly in the same project. I am using NetBeans 7.0 with GlassFish 3.1 and PrimeFaces 3.0.M2, the latest drop (20th June 2011).
The source code of the JSF page and the managed bean is attached.
<?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:p="http://primefaces.prime.com.tr/ui"
xmlns:f="http://java.sun.com/jsf/core">
<h:head><title>Facelet Title</title></h:head>
<h:body>
<p:log />
<center>
<h:form>
<h:outputText value="State: "/>
<p:selectOneMenu id="selectState" value="#{stateCityBean.selectedStateArray}">
<f:selectItem itemLabel="Select Any" itemValue="Empty String"/>
<p:ajax update="selectCity" listener="#{stateCityBean.updateCityMap}"/>
<f:selectItems value="#{stateCityBean.stateMap}" />
</p:selectOneMenu>
<p></p>
<h:outputText value="City: "/>
<p:selectOneMenu id="selectCity" value="#{stateCityBean.selectedCityArray}">
<f:selectItem itemLabel="Select Any" itemValue="Empty String"/>
<f:selectItems value="#{stateCityBean.cityMap}"/>
</p:selectOneMenu>
</h:form>
</center>
</h:body>
StateCityBean.java
package com.xyz.mbeans;
import com.iwizability.priceinfo.dao.*;
import com.iwizability.priceinfo.pojo.*;
import java.util.LinkedHashMap;
import java.util.Map;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
import javax.faces.context.FacesContext;
import javax.faces.context.Flash;
import javax.faces.event.ValueChangeEvent;
@ManagedBean
@SessionScoped
public class StateCityBean {
private String selectedStateArray;
private Map<String, State> StateMap;
private Map<String, City> CityMap;
private String selectedCityArray;
public StateCityBean() {
System.out.println("Inside.............. ");
StateMap = new LinkedHashMap<String, State>();
CityMap = new LinkedHashMap<String, City>();
}
public String getSelectedStateArray() {return selectedStateArray;}
public void setSelectedStateArray(String selectedStateArray) {this.selectedStateArray = selectedStateArray;}
public Map<String, State> getStateMap() {
StateDaoImpl stateObj = new StateDaoImpl();
StateMap = stateObj.getState();
return StateMap;
}
public void setStateMap(Map<String, State> stateArray) {this.StateMap = stateArray;}
public String getSelectedCityArray() {return selectedCityArray;}
public void setSelectedCityArray(String selectedCityArray) {this.selectedCityArray = selectedCityArray;}
public Map<String, City> getCityMap() {
CityDaoImpl cityObj = new CityDaoImpl();
int stateId = 0;
if (selectedStateArray != null && !selectedStateArray.equals("")) {
stateId = StateMap.get(selectedStateArray).getId();
}
CityMap = cityObj.getCity(stateId);
return CityMap;
}
public void setCityMap(Map<String, City> CityArray) {
this.CityMap = CityArray;
}
public void updateCityMap() {
CityDaoImpl cityObj = new CityDaoImpl();
int stateId = 0;
if (selectedStateArray != null && !selectedStateArray.equals("")) {
stateId = StateMap.get(selectedStateArray).getId();
this.CityMap = cityObj.getCity(stateId);
}
}
}
On debugging, I can see that the updateCityMap method is invoked but the SelectedStateArray variable is null. Even force changing the value of bound CityMap variable does not update the selectCity drop down.
As you would have guessed, I am new to JSF, but the problem is compounded by the fact that I am using a still in development version of the tag library...
Answer
I created a demo for the exact same situation you describe in your project. I have a state and city <p:selectOneMenu/> elements on my page. You select a state, and the cities update. If a different state is selected, the city is erased since it may not exist in the state.
The difference is that I use <p:ajax event="change" update="cities, cs"/> to update the elements, and an actionListener to update the city if the state is different.
<p:selectOneMenu id="states" value="#{dataBean.selectedState}"
valueChangeListener="#{dataBean.stateChangeListener(event)}"
style="width: 150px;">
<f:selectItem itemLabel="" itemValue=""/>
<f:selectItems value="#{dataBean.states}"/>
<p:ajax event="change" update="cities, cs"/>
</p:selectOneMenu>
<h:outputLabel value="City:" for="cities"/>
<p:selectOneMenu id="cities"
value="#{dataBean.selectedCity}"
style="width: 150px;">
<f:selectItem itemLabel="" itemValue=""/>
<f:selectItems value="#{dataBean.cities}"/>
<p:ajax event="change" update="cs" />
</p:selectOneMenu>
The whole project and demo code can be found on my blog. I saw this post and decided to post my project. [blog]: http://javaevangelist.blogspot.com/2012/07/primefaces-ajax-enabled.html