Hi

I am trying to make two interdependent selectOneMenu objects, but i must be missing something because in every example i see, there is not much code involved but i can't get it to work

this is the code in the page:

 <h:form id="agenciaForm">
 <a4j:outputPanel ajaxRendered="true">
 <h:messages errorClass="errorMessageStyle" infoClass="infoMessageStyle" showDetail="true" showSummary="false" layout="table"/>
 </a4j:outputPanel>
 <h:panelGrid columns="2">
 <h:outputLabel value="Provincia:" styleClass="normal"/>
 <h:selectOneMenu id="provincia" value="#{agenciaManager.provincia}" title="Provincia" styleClass="normal">
 <f:selectItem itemValue="" itemLabel="Seleccione" />
 <f:selectItems value="#{agenciaManager.provincias}"/>
 <a4j:support id="provinciaSupport" event="onchange" reRender="canton" immediate="true"/>
 </h:selectOneMenu>

 <h:outputLabel value="Ciudad:" styleClass="normal"/>
 <h:selectOneMenu id="canton" value="#{agenciaManager.canton}" title="Canton" styleClass="normal">
 <f:selectItem itemValue="" itemLabel="Seleccione" />
 <f:selectItems value="#{agenciaManager.cantones}"/>
 </h:selectOneMenu>

 </h:panelGrid>
 </h:form>

The a4j:support is immediate="true" because in the form, i have some required objects

This is the backingBean code:

 private String provincia;
 private String canton;

 public SelectItem[] getProvincias(){
 List<Provincia> provincias = provinciaServiceDelegate.findAllSort();
 SelectItem items[] = new SelectItem[provincias.size()];
 int i = 0;
 for (Provincia provincia : provincias) {
 items = new SelectItem(provincia.getProvinciaPK().getProvincia(), provincia.getDescripcion());
 i++;
 }
 return items;
 }

 public SelectItem[] getCantones() {
 System.out.println("getCantones >>> provincia >>> " + provincia);
 SelectItem items[] = new SelectItem[0];
 if (provincia != null && !provincia.equals("")) {
 ProvinciaPK pk = new ProvinciaPK();
 pk.setPais("01");
 pk.setProvincia(provincia);
 List<Canton> cantones = cantonServiceDelegate.findByProvincia(pk);
 items = new SelectItem[cantones.size()];
 int i = 0;
 for(Canton canton : cantones) {
 items = new SelectItem(canton.getArcccanPK().getCanton(), canton.getDescripcion());
 i++;
 }
 }

 return items;
 }

the thing is that i want the canton h:selectOneMenu to be refreshed when i select a provincia h:selectOneMenu

but the problem is that when the getCantones method is triggered the provincia value is always null, so i dont find any related cantones (its a parent-child relation)

what am i missing ??

is there any complete example that i can follow ??

thanks a lot