Question

I am creating a simple page that will, after clicking a button, replace one panelGroup with another. First, the code:

<h:body>

    <ui:composition template="/elements/templateWithMenu.xhtml">           
        <ui:define name="content">
            <div class="rightContent">

                <h:panelGroup id="lol" rendered="#{test.firstStep.booleanValue()}">

                    <h3>This should disappear</h3>

                    <h:form id="newPollForm1" rendered="#{test.firstStep.booleanValue()}"> 
                        <fieldset>
                            <h:commandLink value="Next" action="#{test.firstStepCompleted()}" >
                                <f:ajax execute="@all" render="lol" />
                            </h:commandLink>
                        </fieldset>
                    </h:form>

                </h:panelGroup>

                <h:panelGroup rendered="#{test.secondStep.booleanValue()}">
                    Works!
                </h:panelGroup>

            </div>     
        </ui:define>
    </ui:composition>

</h:body>

The backing bean simply sets the firstStep as false, and secondStep as true.

Now, when I tried running this, I got <f:ajax> contains an unknown id 'lol' - cannot locate it in the context of the component j_idt39. After googling a bit, I found out that for elements outside the form’s scope, I need to use SEPARATOR_CHAR (:). That didn’t work. So I tried messing with different combinations of #{component} and #{cc}, but nothing works. I even found this awesome explanation, but again, I failed miserably. If I use @all, everything goes ok (one panel is replaced with another), but I really need to render a specific component.

Help? Please?

Answer 1

You need to update the common parent <div class="rightContent"> instead. This one is always rendered and thus guarantees that JavaScript/Ajax can access and mainpulate its children. Replace it by <h:panelGroup layout="block"> and give it an id.

<h:panelGroup layout="block" id="content" class="rightContent">
    <h:panelGroup rendered="#{test.firstStep}">
        <h3>This should disappear</h3>
        <h:form id="newPollForm1"> 
            <fieldset>
                <h:commandLink value="Next" action="#{test.firstStepCompleted()}" >
                    <f:ajax execute="@form" render=":content" />
                </h:commandLink>
            </fieldset>
        </h:form>
    </h:panelGroup>

    <h:panelGroup rendered="#{test.secondStep}">
        Works!
    </h:panelGroup>
</h:panelGroup>

Using this Test.java class:

import javax.faces.bean.ManagedBean;
import javax.faces.bean.ViewScoped;

@ManagedBean
@ViewScoped
public class Test {
    private int number = 0;

    public void firstStepCompleted() {
        number++;
    }

    public boolean isFirstStep() {
        return number == 0;
    }

    public boolean isSecondStep() {
        return number == 1;
    }
}

Note that I removed the superfluous Boolean#booleanValue() calls and the duplicated rendered contition on the form.

If that still doesn’t work, then the /elements/templateWithMenu.xhtml apparently contains another naming container component which has prepended its ID. For starters who haven’t memorized all naming container components yet, an easy way to figure the real right client ID is to open the page in browser, rightclick and View Source and then locate the JSF-generated HTML element and take exactly its id attribute value (and prefix it with : in the <f:ajax render>).