Populating a chlid jSF selectOneMenu - implicit value validation error - ajax

Question

As you can see in the screenshot, I am having a JSF implicit value validation error for the property "member.city".
The purpose is to -through ajax - populate the city select One Menu after selecting a country on the previous Country Select one menu.
This is achieved by using selectOneMenu change listener and ajax to update the component displaying list of cities. However, I get a validation error and the form is not submitted.
I tried with Entities with and without (hascode and equals methods), but in vain.
I used a separated Managed Bean ViewScoped to retrive the filtered list, but in vain.
**
If I replace the filtered list of cities by the list that retrieves all
cities (in the xhtml form, replace <f:selectItems value="#{cityBean.citiesByCountry}" /> by <f:selectItems value="#{cityBean.all}" />, there's no validation error and the form successfully gets
submitted.
**
Here is the code:
Form:
<p:outputLabel for="country" value="#{i18n.country}" />
<p:selectOneMenu valueChangeListener="#{cityBean.selectCountry}" rendered="true" id="country" value="#{newMember.country}" converter="#{countryBean.converter}"
style="width:160px;text-align:left;border:thin solid gray;"
required="true" requiredMessage="#{i18n.required}">
<f:selectItems value="#{countryBean.all}" var="countryname" itemLabel="#{countryname.name}"/>
<p:ajax event="change" update="city" />
</p:selectOneMenu>
<p:message for="country" />
<p:outputLabel for="city" value="#{i18n.city}" />
<p:selectOneMenu rendered="true" id="city" value="#{newMember.city}" converter="#{cityBean.converter}" converterMessage="Conversion error!"
style="width:160px;text-align:left;border:thin solid gray;"
required="true" requiredMessage="#{i18n.required}">
<f:selectItems value="#{cityBean.citiesByCountry}" var="cityname" itemLabel="#{cityname.cityname}"/>
</p:selectOneMenu>
<p:message for="city" />
City Entity head:
#XmlRootElement
#Entity
#Table(name = "city", schema = "public")
#NamedQueries({
#NamedQuery(name = "City.findAll", query = "SELECT c FROM City c"),
#NamedQuery(name = "City.findById", query = "SELECT c FROM City c WHERE c.id = :id"),
#NamedQuery(name = "City.findByCountry", query = "SELECT c FROM City c WHERE c.country = :country"),
#NamedQuery(name = "City.findByCountryOrderedByName", query = "SELECT c FROM City c WHERE c.country = :country ORDER BY c.cityname ASC") })
#NamedNativeQueries({ #NamedNativeQuery(name = "City.findCountryNativeSQL", query = "select * from city c where c.countrybeta = :country.betacode", resultClass = City.class) })
public class City implements java.io.Serializable {
private static final long serialVersionUID = 3364735938266980295L;
private int id;
private Integer version;
private Country country;
private String cityname;
private String district;
private int population;
private Set<Member> members = new HashSet<Member>(0);
public City() {
}
// ...remainder of entity code (contructors and fields..)
The Bean:
#Named
#Stateful
#ConversationScoped
public class CityBean implements Serializable {
private static final long serialVersionUID = 1L;
private City city;
private List<City> cityList;
public City getCity() {
return this.city;
}
private Country selectedCountry;
#Inject
private Conversation conversation;
#PersistenceContext(type = PersistenceContextType.EXTENDED)
private EntityManager entityManager;
// remainder of code....
// The List that works fine with Select one Menu
public List<City> getAll() {
CriteriaQuery<City> criteria = this.entityManager.getCriteriaBuilder()
.createQuery(City.class);
return this.entityManager.createQuery(
criteria.select(criteria.from(City.class))).getResultList();
}
#PostConstruct
public void init() {
setCityList(getCitiesByCountry());
}
public List<City> getCityList() {
return cityList;
}
public void setCityList(List<City> cityList) {
this.cityList = cityList;
}
/**
* The List That triggers a jsf value validation error
* #return List of Cities by Country ordered by city name
*/
public List<City> getCitiesByCountry() {
TypedQuery<City> query = this.entityManager.createNamedQuery(
"City.findByCountryOrderedByName", City.class);
query.setParameter("country", selectedCountry);
return query.getResultList();
}
// The Select One Menu Listener
public void selectCountry(ValueChangeEvent event) {
if (event != null) {
selectedCountry = (Country) event.getNewValue();
}
}
// getters and setters....
ENV:
- JSF 21
- Hibernate
- JBoss AS 7.1
- PrimeFaces 3.5
- Linux 3.5 / Firefox 18.0.2

Answer 1

Your concrete problem is caused because you aren't starting the conversation in #PostConstruct and thus the bean behaves like request scoped. This way the list of cities will incompatibly change during processing the form submit and become empty (and thus the selected item couldn't be found in the list of available items and hence this validation error).
You need to start the conversation in the #PostConstruct.
conversation.begin();
See also:
How to replace #ManagedBean / #ViewScope by CDI in JSF 2.0/2.1
Validation Error: Value is not valid
Unrelated to the concrete problem, using valueChangeListener and performing business logic in getter methods is the wrong approach. You should not be performing business logic in getter methods at all. This is plain inefficient. They should solely return already-prepared bean properties.
Rewrite your logic as follows:
<p:selectOneMenu value="#{bean.country}" ...>
<f:selectItems value="#{bean.countries}" />
<p:ajax listener="#{bean.updateCities}" update="city" />
</p:selectOneMenu>
<p:selectOneMenu id="city" value="#{bean.city}" ...>
<f:selectItems value="#{bean.cities}" />
</p:selectOneMenu>
with
private Country country;
private List<Country> countries;
private City city;
private List<City> cities;
#PostConstruct
public void init() {
countries = service.listCountries();
public void updateCities() {
cities = service.listCities(country);
}
// Add/generate normal!! getters/setters.
See also:
Why JSF calls getters multiple times
Our selectOneMenu tag wiki page