I'm using rich faces 3.3.0 and the extended data table with a data table scroller. We're using the data scroller, because we're displaying a given user's activities, and that user might have thousands. Because of this, I need to disable the client side sorting, and capture the "onsort" event so that I can have our service perform the sorting and return to me the set of activities the user wants to see.
Along with this, I'm wondering if there's a way to disable the "group by functionality" as well?
Here's the code:

<a4j:outputPanel>
 <h:form>
 <div>
 <rich:extendedDataTable id="activitiesGrid" value="#{activitiesListingDataModel}" var="row"
 rows="20" sortMode="single" style="width: 3000px; height: 524px"
 selectionMode="multi"
 tableState="#{activityListingDataProvider.activitiesTableState}"
 cellpadding="5" rowClasses="activityRow, activityRowAlternate"
 onRowMouseOver="activitiesHandler.highlightRow(this)"
 onRowMouseOut="activitiesHandler.unHighlightRow(this)">
 <rich:column id="activityNameColumn" sortable="true" label="#{field_activityName}"
 sortBy="#{row.activityName}" width="150px">
 <f:facet name="header">
 <h:outputText value="#{field_activityName}"/>
 </f:facet>
 <h:outputLink value="/activity/#{row.activityId}">
 <h:outputText value="#{row.activityName}" title="#{row.activityName}"/>
 </h:outputLink>
 </rich:column>
 <rich:column id="activityTypeColumn" sortable="true" label="#{field_activityType}"
 sortBy="#{row.activityTypeName}" width="100px">
 <f:facet name="header">
 <h:outputText value="#{field_activityType}"/>
 </f:facet>
 <h:outputText value="#{row.activityTypeName}"/>
 </rich:column>
 <rich:column id="locationColumn" sortable="true" label="#{field_location}"
 sortBy="#{row.locationName}" width="150px">
 <f:facet name="header">
 <h:outputText value="#{field_location}"/>
 </f:facet>
 <h:outputText value="#{row.locationName}" title="#{row.locationName}"/>
 </rich:column>
 <rich:column id="eventTypeColumn" sortable="true" label="#{field_eventType}"
 sortBy="#{row.eventTypeName}" visible="false" width="100px">
 <f:facet name="header">
 <h:outputText value="#{field_eventType}"/>
 </f:facet>
 <h:outputText value="#{row.eventTypeName}"/>
 </rich:column>
 </rich:extendedDataTable>
 </div>
 <div class="activitiesFooterLeft">
 <rich:datascroller id="pageScroller" for="activitiesGrid"
 page="#{activityListingDataProvider.scrollerPage}"
 align="center" maxPages="10" tableStyleClass="paginationTableStyle"/>
 </div>
 </h:form>
</a4j:outputPanel>