p:selectOneMenu does not set value in bean

Question

Quick question. This hasn't happened to me before when working with SelectOneMenu. This is my code.

<h:outputLabel for="listaRegiones" value="Región: " />
<p:selectOneMenu id="listaRegiones" value="#{nuevaProvincia.regionSelect}" required="true">
    <f:selectItems value="#{nuevaProvincia.regiones}" />
</p:selectOneMenu>
<p:message for="listaRegiones" />

And this is my backing bean.

@ManagedBean(name="nuevaProvincia")
@ViewScoped
public class nuevaProvincia implements Serializable {

    public static final long serialVersionUID = 1L;

    public nuevaProvincia() throws DAOException {
        this.provincia = new Provincia();
        this.regiones = new ArrayList<SelectItem>();
        ArrayList<Region> regs = new ArrayList<Region>();
        try
        {
            regs = Region.obtenerRegiones();
        }
        catch(DAOException e)
        {
            FacesContext.getCurrentInstance().addMessage(null, new FacesMessage(FacesMessage.SEVERITY_FATAL, "Hubo un error: "+e.getMessage(), "Hubo un error: "+e.getMessage()));
        }
        if(regs.size()>0)
        {
            for(Region r : regs)
            {
                SelectItem item = new SelectItem(r.getCodigo(), r.getNombre());
                regiones.add(item);
            }
            this.regionSelect = regs.get(0).getCodigo();
        }
        else
            this.regionSelect = "";
    }

    public void verificaProvincia() throws DAOException {
        provincia.getRegion().setCodigo(regionSelect);
        try
        {
            if(this.provincia.estaCreado())
                FacesContext.getCurrentInstance().addMessage("frmIngProvincia:provCodigo", new FacesMessage(FacesMessage.SEVERITY_WARN, "El código de provincia ingresado ya existe.", "El código de provincia ingresado ya existe."));
            else
                FacesContext.getCurrentInstance().addMessage("frmIngProvincia:provCodigo", new FacesMessage(FacesMessage.SEVERITY_INFO, "El código de provincia ingresado no existe.", "El código de provincia ingresado no existe."));
        }
        catch(DAOException e)
        {
            FacesContext.getCurrentInstance().addMessage(null, new FacesMessage(FacesMessage.SEVERITY_FATAL, "Hubo un error: "+e.getMessage(), "Hubo un error: "+e.getMessage()));
        }
    }

    public void insertaProvincia() throws DAOException {
        try
        {
            provincia.getRegion().setCodigo(regionSelect);
            provincia.guardar();
            FacesContext.getCurrentInstance().addMessage(null, new FacesMessage(FacesMessage.SEVERITY_INFO, "Provincia ingresada con éxito", "Provincia ingresada con éxito"));
        }
        catch(DAOException e)
        {
            FacesContext.getCurrentInstance().addMessage(null, new FacesMessage(FacesMessage.SEVERITY_ERROR, "Hubo un error: "+e.getMessage(), "Hubo un error: "+e.getMessage()));
            throw e;
        }
    }

    //Getters and setters for everything        

    //Privados
    private Provincia provincia;
    private String regionSelect;
    private List<SelectItem> regiones;
}

The problem is as follows: whenever I change the value in my selectonemenu, the value in the backing bean is not being set (although I do have a setter for regionSelect). Why would this happen?

If your line SelectItem item = new SelectItem(r.getCodigo(), r.getNombre()); is giving something else than String as ItemValue, you will get a bad value error (you can try using to see if something is going wrong) — Alexandre Lavoie, Nov 10 '12 at 22:36
Both values set in SelectItem are strings, and `` is not telling me anything new. — Carlos Vergara, Nov 10 '12 at 22:41
Have you other fields in this form? If yes, does other fields are updated? — Alexandre Lavoie, Nov 10 '12 at 22:46
Wha ... I didn't really make any change and it's working. Thank you. — Carlos Vergara, Nov 11 '12 at 00:48

score 29 · Accepted Answer · answered Nov 11 '12 at 00:58

29

I found the error and it was ... quite strange and circumstantial. I added the following line inside the SelectOneMenu:

<p:ajax event="change" update="@this" />

and now it works just fine.

answered Nov 11 '12 at 00:58

Carlos Vergara

3,592
4
31
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1

Excellent, I'm still using RichFaces so I think there are some differences! – Alexandre Lavoie Nov 11 '12 at 03:56
It's possible both are quite different on their behaviors! – Carlos Vergara Nov 11 '12 at 05:50
3

This is the expected behavior. Your example will set the `selectOneMenu` value on form submit. If you want to set it with ajax, you have to specify it. Please mark your post as answer. – Akos K Nov 11 '12 at 09:27
1

I'm going to mark it as my answer, only that I must wait until tomorrow. Also, does it mean I should place a `p:ajax` in every `SelectOneMenu` I want to verify during runtime? – Carlos Vergara Nov 11 '12 at 19:55
I have the same case with inputTexfield, do I need to use ajax for the same ? – Alok Jun 29 '15 at 07:54
I've not used JSF for ages so I kinda forgot, but iirc, it shouldn't apply given it's just an inputTextField rather than a selectOneMenu. Try using it though and see if it works. Or maybe your field is not mapped to the bean? I don't know anymore! – Carlos Vergara Jun 29 '15 at 21:31

score 1 · Answer 2 · answered Jan 12 '14 at 11:03

<p:selectOneMenu id="listaRegiones" value="#{nuevaProvincia.regionSelect}" required="true">
    <f:selectItems value="#{nuevaProvincia.regiones}" />
</p:selectOneMenu>

should be

<p:selectOneMenu id="listaRegiones" value="#{nuevaProvincia.regionSelect}" required="true">
    <f:selectItems value="#{nuevaProvincia.regiones}" var="region" 
      itemValue = "#{region}"/>
</p:selectOneMenu>

That's why you have to have the ajax call to update whenever there is a change. You are never setting the value.

Does `var="region" itemValue="#{region}"` do that was questioned? — Jin Kwon, Nov 09 '16 at 07:31

score 0 · Answer 3 · answered Mar 11 '19 at 03:01

0

If you are working objects in the value, check the equals() function.

answered Mar 11 '19 at 03:01

Carlos UCR

299
3
6

score -1 · Answer 4 · edited Dec 10 '15 at 17:35

-1

I discovered when I had this problem it was because of the @ViewScoped. Using SessionScoped instead worked fine.

One interesting thing is that in another project, with ViewScoped, it worked. I cannot explain.

edited Dec 10 '15 at 17:35

Nathaniel Ford

20,545
20
91
102

answered Dec 10 '15 at 17:17

Rogério Marchiori

63
1
2
7

2

You most likely used the wrong combination of `@ViewScoped` and `@Named`/`@ManagedBean` Annotation. If you would have taken the wrong `@SessionScoped` it would have failed to... – Kukeltje Dec 10 '15 at 17:41

p:selectOneMenu does not set value in bean

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