How to Refresh Datatable Dynamic Columns After Pagination

Question

I use primefaces 3.1 and I have a datatable that shows paginated data, whose columns are constructed based on the data of the page and rendered via <p:columns/> tag. With this approach, different pages of the same datatable can have different columns. I tought it would re-render columns on pagination by default, but it doesn't. Ive tried <p:ajax event="page" update="myTable"/> and <p:ajax event="page" update="myTableContainer"/> with any luck.

Is there a way to re-render the whole datatable when pagination is triggered, so not only content but column headers are showed properly?

Edit: Heres some code sample as you requested.

Ive made my own implementation of LazyDataModel and extended it overriding the load method implementation:

@Override
public List<StockItem> load(int i, int i1, String string, SortOrder sortOrder, Map<String, String> map) {
    List<StockItem> stockItems = super.load(i, i1, string, sortOrder, map);
    inventoryMovements = service.listInventoryMovements(stockItems, fromDate, toDate);
    stockOperations = new HashSet<StockOperation>();
    quantityTypes = new HashSet<QuantityType>();
    for (Map.Entry<StockItem, ItemMovements> entry : inventoryMovements.entrySet()) {
        quantityTypes.addAll(entry.getValue().getStartingQuantities().keySet());
        quantityTypes.addAll(entry.getValue().getEndingQuantities().keySet());
        stockOperations.addAll(entry.getValue().getOperationsApplied().keySet());
    }
    return stockItems;
}

As you see in the method, i fill both stockOperations and quantityTypes on every page load. These two correspond to my actual page columns. (These are atributes in my LazyDataModel implementation with their corresponding getters)

<p:dataTable id="movementsTable" var="item" 
                                 value="#{inventoryMovementsBean.view}" 
                                 rowIndexVar="rowIndex" 
                                 paginator="true"
                                 rows="25">
                        <p:column headerText="Item">
                            <h:outputText value="#{item.label}" />
                        </p:column>
                        <p:columns value="#{inventoryMovementsBean.view.quantityTypes}" var="quantityType" columnIndexVar="quantityTypeIndex">
                            <f:facet name="header">
                                #{quantityType.description}
                            </f:facet>
                            <h:outputText value="#{inventoryMovementsBean.view.getStartingQuantity(item, quantityType)} => #{inventoryMovementsBean.view.getEndingQuantity(item, quantityType)}" />
                        </p:columns>
                        <p:columns value="#{inventoryMovementsBean.view.stockOperations}" var="stockOperation" columnIndexVar="stockOperationIndex">
                            <f:facet name="header">
                                #{stockOperation.name}
                            </f:facet>
                            <h:outputText value="#{inventoryMovementsBean.view.getOperationValue(item, stockOperation)}" />
                        </p:columns>
                    </p:dataTable>

inventoryMovementsBean.view is my LazyDataModel instance and methods getOperationValue(item, stockOperation), getStartingQuantity(item, quantityType) and getEndingQuantity(item, quantityType) are the ones that give me the content given an item and a column.

Ive already made a debug, and im pretty sure the whole data is loaded propertly, it is just a display problem. Here are some screenshots as additional information.

These images correspond to:

• Initial render (Page 1).
• Actual render after pagination (Page 3)
• Expected render after pagination (Page 3)

Answer 1

If you use Primefaces, There is an option like lazyLoading.If you specify true,then all the client side stuff will be handled in server side.For more

http://www.primefaces.org/showcase/ui/datatableLazy.jsf