empty operator always returns false after a @DataModel refresh event

[chawax]

Hi,

I encounter problems using @DataModel annotation and <rich:datatable> tag. The empty operator doesn't work when refreshing the content after an event is raised ; it always returns false.

My @DataModel is as following :

@org.jboss.seam.annotations.datamodel.DataModel
protected VOTacheValidationDemandeAbsence[] listeDemandesAbsenceAValider;

I have a @Factory method :

@org.jboss.seam.annotations.Factory(value="listeDemandesAbsenceAValider")
@javax.ejb.TransactionAttribute(javax.ejb.TransactionAttributeType.REQUIRES_NEW)
@org.jboss.seam.annotations.Observer("listeDemandesAbsenceAValiderUpdated")
public void loadListeDemandesAbsenceAValider() 
{
    this.listeDemandesAbsenceAValider = getServiceAbsence().listerDemandesAbsenceAValider(this.actor.getId());
}

A method which raise the event to refresh the data model :

public void choisirTransitionTache(Long taskId, String transition)
throws java.lang.Exception
{
    this.processHandler.followTransition(taskId, transition);
    this.events.raiseEvent("listeDemandesAbsenceAValiderUpdated");
}

And part of the facelet :

<h:outputText value="#{messages['label.validationDemandesAbsence.empty']}" rendered="#{empty listeDemandesAbsenceAValider}"/>
<rich:dataTable value="#{listeDemandesAbsenceAValider}" var="task" rendered="#{not empty listeDemandesAbsenceAValider}">
<rich:column>
     <a4j:commandLink
          id="cmdDetail" 
          value="#{task.descriptionTache}" 
          action="#{validationDemandesAbsenceAction.detailDemandeAbsence(task.demandeAbsence)}" 
          reRender="wrapperDetailDemandeAbsence"
          oncomplete="Richfaces.showModalPanel('panelDetailDemandeAbsence')" />
</rich:column>
<rich:column>
     <h:outputText value="#{task.demandeAbsence.dateDemande}">
          <s:convertDateTime type="date"/>
     </h:outputText>
</rich:column>
<rich:column>
     <s:button value="#{messages['label.demandeAbsence.accepter']}" action="#{validationDemandesAbsenceAction.choisirTransitionTache(task.idTache, 'ok')}"  />
     <s:button value="#{messages['label.demandeAbsence.refuser']}" action="#{validationDemandesAbsenceAction.choisirTransitionTache(task.idTache, 'nok')}"  />
</rich:column>
</rich:dataTable>

It works well the first time. But when I call the method firing the refresh event, the empty operator always returns false while the list is empty (rowcount = 0 when I look at it in debug page). Same problem if the data model is a List. But if I stop using @DataModel and use @Out instead, no more problems ! So I think this is really a problem with @DataModel annotation.

Anyone has an idea what this problem comes from ?

[pmuir]

Don't you want to use rendered="#{dataModel.rowCount > 0}" - the empty operator checks if the EL variable is null IIRC.

[chawax]

You are right, it works using rowCount attribute instead of empty operator.

Anyway I think it is juste a way to workaround a real problem since empty operator doesn't work correctly for datamodels. If you read the JSF documentation on Sun website ( http://java.sun.com/j2ee/1.4/docs/tutorial/doc/JSPIntro7.html ), they say :

Empty: The empty operator is a prefix operation that can be used to determine whether a value is null or empty.

That's not what the empty operator does with datamodels in my case ;)

[pmuir]

File a bug against the JSF RI.