Primefaces DataTable with SubTable and multiple selection - jsf

Question

I would like to have a table of bookings grouped by clients. From this table the user shall be able to select multiple booking for billing. So I am trying to use a SubTable for the grouping, however, I am unsure how to realize to selection functionality. Apparently the subtable doesn't allow the selection attribute and if I set the selection attribute on the parent DataTable I don't know how to choose the rowKey.
That is my try:
<p:dataTable style="border: 0px;" value='#{clientController.allClients}'
var='client' rowKey="#{item.id}" selectionMode="multiple"
selection="#{bookingController.bookingsToBill}">
<p:subTable value='#{client.billableBookings}' var='item'>
<f:facet name="header">
<h:outputText style="font-weight:bold;" value="#{client.name}" />
</f:facet>
<p:column>
<f:facet name="header">
<h:outputText value="Booking"/>
</f:facet>
<h:outputText value="#{item.title}"/>
</p:column>
</p:subTable>
</p:dataTable>
Well, this results in the following error when submitting the selection:
java.lang.NullPointerException
java.lang.reflect.Array.newArray(Native Method)
java.lang.reflect.Array.newInstance(Array.java:52)
org.primefaces.component.datatable.DataHelper.decodeMultipleSelection(DataHelper.java:238)
org.primefaces.component.datatable.DataHelper.decodeSelection(DataHelper.java:224)
org.primefaces.component.datatable.DataTableRenderer.decode(DataTableRenderer.java:64)
javax.faces.component.UIComponentBase.decode(UIComponentBase.java:787)
javax.faces.component.UIData.processDecodes(UIData.java:1162)
org.primefaces.component.datatable.DataTable.processDecodes(DataTable.java:531)
javax.faces.component.UIForm.processDecodes(UIForm.java:225)
javax.faces.component.UIComponentBase.processDecodes(UIComponentBase.java:1176)
javax.faces.component.UIComponentBase.processDecodes(UIComponentBase.java:1176)
javax.faces.component.UIViewRoot.processDecodes(UIViewRoot.java:933)
com.sun.faces.lifecycle.ApplyRequestValuesPhase.execute(ApplyRequestValuesPhase.java:78)
com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
javax.faces.webapp.FacesServlet.service(FacesServlet.java:409)
Is multiple selection supported for DataTables with SubTables? If so, how to do it right? If not, which way would you suggest to achieve a similar result?
I'm using: Primefaces 3.1.1 - Mojarra JSF 2.1 - Tomcat 6.0.14

Answer 1

Have you analyzed this solution described in Primefaces' showcase?
It basically boils down to this:
<p:dataTable style="border: 0px;" value='#{clientController.allClients}'
var='client' rowKey="#{item.id}"
selection="#{bookingController.bookingsToBill}" >
<p:subTable value='#{client.billableBookings}' var='item'>
<f:facet name="header">
<h:outputText style="font-weight:bold;" value="#{client.name}" />
</f:facet>
<p:column selectionMode="multiple" />
<p:column>
<f:facet name="header">
<h:outputText value="Booking"/>
</f:facet>
<h:outputText value="#{item.title}"/>
</p:column>
</p:subTable>
Or try with the ajax event listener, bound to your BookingController:
<p:ajax event="rowSelect" listener="#{bookingController.rowSelected}" />
<p:ajax event="rowUnselect" listener="#{bookingController.rowUnselected}" />
And you update your own list of selected items in these two functions:
List<Booking> selectedBookings = new ArrayList<>();
...
public void rowSelected(SelectEvent event) {
Booking book = (Booking) event.getObject();
selectedBookings.add(book);
}
public void rowUnselected(UnselectEvent event) {
Booking book = (Booking) event.getObject();
selectedBookings.remove(book);
}
It's not very elegant, but it brought my logic to work after getting this rather obscure NullPointerException.