JSF - selectItems doesn't render list inside of list

Question

I have the following facelet code which is failing:

<h:form>
    <rich:select defaultLabel="Seleccionar región">
        <f:selectItems value="#{StaticInfo.regiones}" var="region" itemValue="#{region.reg_Cod}" itemLabel="#{region.reg_Nombre}" />
        <a4j:ajax event="change" render="provs" />
    </rich:select>
    <rich:select id="provs" defaultLabel="Seleccionar provincia">
    <f:selectItems value="#{region.provincias}" var="prov" itemValue="#{prov.prov_Cod}" itemLabel="#{prov.prov_Nombre}" />
    </rich:select>
</h:form>

Backing bean:

public class StaticInfoBean {

    private ArrayList<Region> regiones;

    public StaticInfoBean() {
        try
        {
            RegionDAO regDao = new RegionDAO();
            regDao.prepareConnection();
            ProvinciaDAO provDao = new ProvinciaDAO();
            provDao.setCon(regDao.getCon());
            ComunaDAO comDao = new ComunaDAO();
            comDao.setCon(regDao.getCon());
            regiones = regDao.listaRegiones();
            for(Region r : regiones)
            {
                regDao.findProvincias(r);
                for(Provincia p : r.getProvincias())
                {
                    provDao.findComunas(p);
                    for(Comuna c : p.getComunas())
                    {
                        comDao.findColegios(c);
                    }
                }
            }
            regDao.getCon().close();
        }
        catch(Exception e)
        {
            System.out.println(e.getMessage());
        }
    }

    public ArrayList<Region> getRegiones() {
        return regiones;
    }

    public void setRegiones(ArrayList<Region> regiones) {
        this.regiones = regiones;
    }

    public String toString() {
        return regiones.toString();
    }

}

Class Region:

public class Region {

    private String Reg_Cod;
    private String Reg_Nombre;
    private ArrayList<Provincia> provincias;
//Getters and setters

The problem: The first rich:select tag works just fine. However the second one doesn't display any value. Not just that, but I'm working in NetBeans and it doesn't display the list of methods for class Provincia whenever I type "prov" in the EL.

Any help is appreciated.

EDIT: I edited my code and did the following:

<h:form>
    <rich:select defaultLabel="Seleccionar región" value="#{StaticInfo.regionElegida}">
        <f:selectItems value="#{StaticInfo.regiones}" var="region" itemValue="#{region.reg_Cod}" itemLabel="#{region.reg_Nombre}" />
        <a4j:ajax event="click" render="provs" execute="@this" />
        <a4j:ajax event="click" render="texto" execute="@this" />
    </rich:select>
<h:outputText id="texto" value="#{StaticInfo.regionElegida.reg_Nombre}" />
    <rich:select id="provs" defaultLabel="Seleccionar provincia" value="#{StaticInfo.provinciaElegida}" rendered="#{not empty StaticInfo.regionElegida}">
        <f:selectItems value="#{StaticInfo.regionElegida.provincias}" var="prov" itemValue="#{prov.prov_Cod}" itemLabel="#{prov.prov_Nombre}" />
    </rich:select>
</h:form>

What's surprising is that the outputText isn't being displayed! Why would this happen?

Request. The values must be loaded each time they're needed in case there's a change in the db during the session. — Carlos Vergara, Jul 31 '12 at 17:10
I edited my post and found a related error, yet I don't know how to solve it. — Carlos Vergara, Jul 31 '12 at 20:07
The outputText you mention is missing on your post. Anyway, you don't need to specify two `a4j:ajax`, you can simply separate ids with spaces, as in `render="provs texto"`. — Elias Dorneles, Jul 31 '12 at 20:16
The outputText is there, look below in my edit. And yeah, I could have done it that way but I'm just debugging. I just added a valueChangeListener to set the value but it's not working either... — Carlos Vergara, Jul 31 '12 at 20:28
I just now realized that you are missing the code to deal with `region.reg_Cod`... Let me update the code to help you with that. — Elias Dorneles, Jul 31 '12 at 23:50

score 2 · Accepted Answer · edited May 23 '17 at 12:03

The variable region set in f:selectItems is only available inside its scope. You have to bind each rich:select to a backing bean property.

So, you need to change your bean code, adding properties for the chosen region to the bean:

public class StaticInfoBean {    
    private ArrayList<Region> regiones;
    private Region regionElegida;
    private Provincia provinciaElegida; // <-- you'll probably want this too...

    // ... getters and setters and your initialization code

    // and you need something to find the real region object that
    // used the reg_Cod value got from rich:select, for now you can try this:
    public void updateRegionElegida(AjaxBehaviorEvent e){
        // set the chosen region to regionElegida,
        // or the poor man's converter
        for (Region region : regiones){
            if(regionElegida.getReg_Cod() == region.getReg_cod()) {
                regionElegida = region;
            }
        }
    }
}

and then change your XHTML to something like this:

<h:form>
    <rich:select value="#{StaticInfo.regionElegida}"
          defaultLabel="Seleccionar región">
        <f:selectItems value="#{StaticInfo.regiones}" var="region"
             itemValue="#{region.reg_Cod}" itemLabel="#{region.reg_Nombre}" />
        <a4j:ajax event="change" render="provs"
             listener="#{StaticInfo.updateRegionElegida}" />
    </rich:select>
    <rich:select id="provs" value="#{StaticInfo.provinciaElegida}"
          defaultLabel="Seleccionar provincia">
        <f:selectItems value="#{StaticInfo.regionElegida.provincias}" var="prov"
            itemValue="#{prov.prov_Cod}" itemLabel="#{prov.prov_Nombre}" />
    </rich:select>
</h:form>

Now, the professional way of doing that conversion thing would be to use a custom converter that can find the appropriate instance of a Region object based on the value of the expression itemValue used for its select widget. Check out this example from another question.

Note that rich:select only adds functionality to the default h:selectOneMenu, you would do good checking out its info page here at SO.

I'd love to say it's working, but it's not. I get the same error, the second `rich:select` doesn't display any value. — Carlos Vergara, Jul 31 '12 at 17:39
@user1231958 I've updated my answer, with more info about dealing with the value from `rich:select`/`h:selectOneMenu`. Please, have a look at that page, it explains a lot of this stuff, with a lot of free examples. :) — Elias Dorneles, Aug 01 '12 at 00:18
Oh god my error was much dumber than I thought - I didn't initialize a list in a constructor!! Thank you very much!! — Carlos Vergara, Aug 01 '12 at 00:52

JSF - selectItems doesn't render list inside of list

1 Answers1