Facelet tag parameter not recognized by PrimeFaces p:ajax

Question

I have a simple Facelet tag:

<ui:composition>
  <ui:insert />
</ui:composition>

which is used in order to avoid declaring multiple c:set tags.
Let's say I registered it in the facelets taglib library with the name view, and use it like this:

<my:view bean="#{myController}">
  <p:inputText value="#{bean.value}>
    <p:ajax event="blur" process="@this" listener="#{bean.handleValueChanged}" />
  </p:inputText>
</my:view>

The attribute value is perfectly resolved by p:inputText, but p:ajax throws this:

Target Unreachable, identifier 'bean' resolved to null
javax.el.PropertyNotFoundException: Target Unreachable, identifier 'bean' resolved to null
    at com.sun.el.parser.AstValue.getTarget(AstValue.java:153)
    at com.sun.el.parser.AstValue.invoke(AstValue.java:237)
    at com.sun.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:302)
    at org.jboss.weld.util.el.ForwardingMethodExpression.invoke(ForwardingMethodExpression.java:39)
    at org.jboss.weld.el.WeldMethodExpression.invoke(WeldMethodExpression.java:50)
    at org.primefaces.component.behavior.ajax.AjaxBehaviorListenerImpl.processAjaxBehavior(AjaxBehaviorListenerImpl.java:47)

Is it a bug or expected behavior?

Update: I just tried the same with f:ajax and it worked!

Btw, the environment is as follows:
Glassfish 3.1.2
PF 3.0, 3.2, 3.3

Update2:
This issue with RichFaces is absolutely identical. Seems to be like a PrimeFaces bug (I'll post an issue on PF bug tracker today).

Sheridan

As promised, I opened the issue on PF bug tracker: code.google.com/p/primefaces/issues/detail?id=4075 – Sheridan

Answer 1

My colleague has just provided a patch to resolve this issue.

The current implementation of AjaxBehaviorListenerImpl#processAjaxBehaviour is as follows:

public void processAjaxBehavior(AjaxBehaviorEvent event) throws AbortProcessingException {
        FacesContext context = FacesContext.getCurrentInstance();
        final ELContext elContext = context.getELContext();

        try{
            listener.invoke(elContext, new Object[]{});
        } catch (MethodNotFoundException mnfe) {
            MethodExpression argListener = context.getApplication().getExpressionFactory().
                        createMethodExpression(elContext, listener.getExpressionString(), null, new Class[]{event.getClass()});

            argListener.invoke(elContext, new Object[]{event});
        }
    }

He proposes to tweak it like this:

import javax.faces.view.facelets.FaceletContext;

---

public void processAjaxBehavior(AjaxBehaviorEvent event) throws AbortProcessingException {
        FacesContext context = FacesContext.getCurrentInstance();
        final ELContext elContext = context.getELContext();

        try{
            listener.invoke(elContext, new Object[]{});
        } catch (MethodNotFoundException mnfe) {
            FaceletContext fc = (FaceletContext) context.getAttributes().get(FaceletContext.FACELET_CONTEXT_KEY);
            MethodExpression argListener = context.getApplication().getExpressionFactory().
                        createMethodExpression(fc, listener.getExpressionString(), null, new Class[]{ event.getClass() });

            argListener.invoke(elContext, new Object[]{ event });
        }
    }

Hopefully this will be approved by PF team.

Sheridan

Nice job! This can theoretically solve a problem which we have when using <p:ajax event="rowEdit"> in a tag file. – Daryl

@Daryl Thanks! Though, all kudos should go to my colleague (I doubt if he has SO account). I just noticed the problem, and he solved it :) Is there an open bug regarding <p:ajax event="rowEdit/> or a question on SO? Just curious, because I haven't come across this issue, so I want to take a look. – Sheridan

No, it's for my job. We've a tag file which contains a <p:column><p:rowEditor> along with a <p:ajax event="rowEdit" listener="#{bean.save}"> so that it can be included as a single tag by <my:rowEditorColumn> in data table. However the <p:ajax> did never invoke the listener method. – Daryl

How can this fix the problem since the original exception is a PropertyNotFoundException and not a MethodNotFoundException? – Cryo

Answer 2

The tweak does not work with my use case which is more complex than a single ui:include.

<c:forEach items="#{items}" var="item">
            <ui:include src="#{item.uri}">
                <ui:param name="itemBean" value="#{item.bean}"/>
            </ui:include>

</c:forEach>

I think the listener's variable mapper must be reused inside the new MethodExpression

Scooter

mention it in comments or ask another question please. SO is not a forum. – Edra

I just cannot, not enough reputation and asking a new question is not a solution. By the way, I have submit a patch to this issue code.google.com/p/primefaces/issues/detail?id=4075 (as nithril) which was accepted and applied – Scooter

sorry about the reputation limit. This problem still exists in current 3.5 did your problems disappear after this fix? – Edra

The problem dissapear as soon as the action method takes an argument of AjaxBehaviorEvent type instead of the PF event. It is complex to fix completely the issue so I think it is an acceptable workaround – Scooter