Question

I want to generate selecOneMenu content when the user types in an inputText field, and respond to combo box selection changes.
The below code updates the contents of the selecOneMenu as the user types. (The typed and the next 9 numbers gets added to the combo box. This is just a simplified example code.)
When the page is loaded, the change event of the selecOneMenu correctly gets fired.
However after typing in the inputValue field, content of selecOneMenu is changed, and the change event is not fired when I select an item.

The code works if ComboBean is session scoped, but I want to avoid this solution if possible.

Is it possible at all to do this?
What is the reason if it is not possible with request scope?

PrimeFaces 2.2
Mojarra 2.0.2
GlassFish 3.0.1
Browser: Chrome, Firefox, IE

combo.xhtml:

<h:head>
    <title>Combo box example</title>
</h:head>

<h:body>
    <h:form>
        <p:panel id="mainPanel">
            <h:panelGroup id="formToSubmit" layout="block">
                <p:messages id="messages" />
                <h:panelGrid columns="2">
                    <h:outputLabel value="Enter a number" />
                    <h:inputText id="inputValue" value="#{comboBean.inputValue}">
                        <p:ajax event="keyup" update="combo"
                            listener="#{comboBean.onKeyUp}" />
                    </h:inputText>

                    <h:outputLabel value="Select a value:" />
                    <h:selectOneMenu id="combo" value="#{comboBean.selectedValue}">
                        <f:selectItem itemLabel="Select a value..."
                            noSelectionOption="true" />
                        <f:selectItems value="#{comboBean.values}" />
                        <p:ajax event="change" update="selectedValue"
                            listener="#{comboBean.valueSelected}" />
                    </h:selectOneMenu>
                    <h:outputLabel value="Selected value:" />
                    <h:inputText id="selectedValue" value="#{comboBean.selectedValue}" />
                </h:panelGrid>
            </h:panelGroup>
        </p:panel>
    </h:form>
</h:body>
</html>

ComboBean.java

package x;

import java.io.Serializable;
import java.util.LinkedList;
import java.util.List;

import javax.annotation.PostConstruct;
import javax.enterprise.context.RequestScoped;
import javax.enterprise.context.SessionScoped;
import javax.inject.Named;

@Named
@RequestScoped
public class ComboBean implements Serializable
{
    private static final long serialVersionUID = 1L;
    private String inputValue;
    private String selectedValue;
    private List<String> values;

    @PostConstruct
    void init()
    {
        System.out.println("init");
        setValues(new LinkedList<String>());
        for(int i = 0; i<10 ; i++)
        {
            getValues().add(""+i);
        }
    }

    public void onKeyUp()
    {
        System.out.println("onkeyUp " + getInputValue());
        setValues(new LinkedList<String>());
        if (inputValue != null)
        {
            try 
            {
                int v = Integer.parseInt(inputValue);
                for(int i = 0; i<10 ; i++)
                {
                    getValues().add(""+(v+i));
                }
            } 
            catch (NumberFormatException ne) 
            {
                //doesn't matter
            }
        }
    }

    public void valueSelected()
    {
        System.out.println("valueSelected " + getSelectedValue());
    }

    public void submit()
    {
        System.out.println("submit " + getInputValue());
    }

    public void setInputValue(String inputValue)
    {
        this.inputValue = inputValue;
    }

    public String getInputValue()
    {
        return inputValue;
    }

    public void setSelectedValue(String selectedValue)
    {
        this.selectedValue = selectedValue;
    }

    public String getSelectedValue()
    {
        return selectedValue;
    }

    public void setValues(List<String> values)
    {
        this.values = values;
    }

    public List<String> getValues()
    {
        return values;
    }

}

Answer 1

The problem is that you reset your list during each request in the init() method. So your selected element will no longer be there.

If you don’t want to use SessionScope, maybe the ViewScope would be a solution: then the bean won’t be reset if the same page is reloaded.