netui-data:pager action to dynamically fetch rows

Question

Hi,
How can I configure a data grid pager to dynamically fetch new rows when a user swap pages through the pager?
I know I can fetch all my rows to a collection / array before rendering the datagrid and set the pager to iterate over it like this:
[Controller]
private List<Ride> rides;
public List<Ride> getRides() {
     return rides;
[Action]
rides = rideDBControl.getAllRides(); // huge amount of data
return forward;
[JSP]
     <div style="border-width:2px;"><netui-data:dataGrid name="currentRidesGrid" dataSource="pageFlow.rides">
          <netui-data:configurePager pagerFormat="prevNext" pageSize="${pageSize}" />
          <netui-data:header>
               <netui-data:headerCell headerText="Name" />
               <netui-data:headerCell headerText="Description" />
          </netui-data:header>
          <netui-data:rows>
               <netui-data:spanCell value="${container.item.name}" style="background-color: #f0f0f0;font-size:14pt;">
               </netui-data:spanCell>
               <netui-data:spanCell value="${container.item.description}">
               </netui-data:spanCell>
          </netui-data:rows>
     </netui-data:dataGrid></div>
But how can I make the pager call a method to update the contents of the collection "rides" according to the current selected page and page size? And how can I obtain the current page and page size inside that method?
I want to paginate queries that may return a huge amount of data (1m + rows), so, fetching all rows at once is impracticable. What I want to do is propagate the current page and page size from the pager to a method that will update the current collection according to a query such as:
Select X, Y, Z
From Table
Where ...
And ROWNUM BETWEEN page * pageSize AND (page + 1) * pageSize
Can anyone help a noob?

Answer 1

For further reference I've found the answer by myself.
To dynamically fetch rows you need to modify the <netui-data:configurePager> tag and include both a pageAction and partialDataSet attributes, e.g.:
<netui-data:configurePager pagerFormat="prevNext" pageSize="${pageSize}" pageAction="pagination" partialDataSet="true" />
Within the pagination action you can obtain the current row and page size from a PagerModel object. You can then update the dataSource (just remember to call the setDataSetSize providing the length of the full dataset so that the pager displays the correct amount of pages), e.g.:
@Jpf.Action(forwards = { @Jpf.Forward(name = "success", navigateTo = Jpf.NavigateTo.currentPage) })
     public Forward pagination() {
          DataGridStateFactory dataGridStateFactory = DataGridStateFactory
                    .getInstance(getRequest());
// Gets the pagerModel object for the grid
          PagerModel pagerModel = dataGridStateFactory.getDataGridState(
                    "currentRidesGrid").getPagerModel();
// => Code to get the entire dataSource size <=
          pagerModel.setDataSetSize(dataSourceSize);
          // Obtain the first row and page size from the model
          int firstRow = pagerModel.getRow();
          int pageSize = pagerModel.getPageSize();
          // => Code to fetch the rows to be displayed <=
          rides = pageRides;
          Forward forward = new Forward("success");
          return forward;
I hope this helps.
Cheers