数据表中使用过滤器的动态计算

Question

I want to dynamically update the sum of dataSet values as I filter and/or paginate a Primefaces dataTable.

The following jQuery example shows exactly the behavior I want: http://datatables.net/examples/advanced_init/footer_callback.html

See below my main code for this issue:

The jsf

<p:columnGroup type="footer">
  <p:row>
    <p:column colspan="6" footerText="Grand Total:" style="text-align:right"/>
      <p:column colspan="7">
        <f:facet name="footer">
          <h:outputText value="#{purchaseOrderController.soma}">
            <f:convertNumber pattern="###,###" locale="pl_PL"/>
          </h:outputText>
        </f:facet>
    </p:column>
  </p:row>
</p:columnGroup>

The method soma:

private float soma;

public float getSoma() {
    for (PurchaseOrder p : getItems()) {
        soma += p.getShippingCost().floatValue();
    }
    return soma;
}

Can someone help me?

Thanks in advance.

Updated code

The bean:

@Named(value = "purchaseOrderController")
@ViewScoped
public class PurchaseOrderController extends AbstractController<PurchaseOrder> implements Serializable {

private float soma = 0;
private float somaFiltered = 0;
private List<PurchaseOrder> filteredPurchaseOrder;

public List<PurchaseOrder> getFilteredPurchaseOrder() {
    return filteredPurchaseOrder;
}

public void setFilteredPurchaseOrder(List<PurchaseOrder> filteredPurchaseOrder) {
    this.filteredPurchaseOrder = filteredPurchaseOrder;
}

//return the sum for the FILTERED list - using this method, get a NullPointerException (the filtered list is null)
public float getSomaFiltered() {
    for (PurchaseOrder p : filteredPurchaseOrder) {
            somaFiltered += p.getQuantity() * p.getShippingCost().floatValue();
    }
    return somaFiltered;
}

//return the sum for the ENTIRE list - using this method it's ok
public float getSoma() {
    for (PurchaseOrder p : getItems()) {
        soma += p.getQuantity() * p.getShippingCost().floatValue();
    }
    return soma;
  }

@Inject
private PurchaseOrderFacade ejbFacade;

public PurchaseOrderController() {
    super(PurchaseOrder.class);
}

}

The jsf (some columns ommited):

<h:form id="PurchaseOrderListForm">
  <p:panel header="#{appBundle.ListPurchaseOrderTitle}">
     <p:dataTable id="datalist" var="item" value="#{purchaseOrderController.items}" 
                  filteredValue="#{purchaseOrderController.filteredPurchaseOrder}"
                  selectionMode="single" selection="#{purchaseOrderController.selected}"
                  rowKey="#{item.orderNum}"
                  paginator="true"
                  rows="10"
                  rowsPerPageTemplate="10,20,30"
                  >

         <p:ajax event="rowSelect"   update="createButton viewButton editButton deleteButton"/>
         <p:ajax event="rowUnselect" update="createButton viewButton editButton deleteButton"/>
         <p:ajax event="filter" listener="#{purchaseOrderController.filteredPurchaseOrder}" update="partialSoma" />

         <p:column sortBy="#{item.quantity}" filterBy="#{item.quantity}">
             <f:facet name="header">
                 <h:outputText value="#{appBundle.ListPurchaseOrderTitle_quantity}"/>
             </f:facet>
             <h:outputText value="#{item.quantity}"/>
         </p:column>
         <p:column sortBy="#{item.shippingCost}" filterBy="#{item.shippingCost}">
             <f:facet name="header">
                 <h:outputText value="#{appBundle.ListPurchaseOrderTitle_shippingCost}"/>
             </f:facet>
             <h:outputText value="#{item.shippingCost}"/>
         </p:column>
         <p:columnGroup type="footer">
             <p:row>
                 <p:column colspan="6" footerText="Grand Total:" style="text-align:right"/>
                    <p:column colspan="7">
                        <f:facet name="footer">
                            <h:outputText id="partialSoma" value="#{purchaseOrderController.somaFiltered}">
                            </h:outputText>
                        </f:facet>
                    </p:column>
                </p:row>
            </p:columnGroup>
        </p:dataTable>
    </p:panel>
</h:form>

Answer 1

sorry for my lateness but I actually not have a lot of time with my work. I took the time yesterday afternoon to built a little working example. Indeed, I faced some problems for updating a footer with AJAX (cfr : http://forum.primefaces.org/viewtopic.php?f=3&t=15658 ) but it is working with a <p:remoteCommand /> workaround.

You can find the Eclipse sample project here , running on JBoss 7.1.1 with JSF Mojarra 2.2.0m12 and JDK 1.7

Answer 2

I think that you can define AJAX calls on PF datatable filtering and/or paging.

<p:dataTable value="#{myBackingBean.values}" var="row" filteredValue="#{myBackingBean.filteredValues}" >
   <p:ajax event="filter" listener="#{myBackingBean.updateSum}" update="componentToUpdate" />
   ...
</p:dataTable>

In your updateSum() method, you can walk through the filteredValues collection to do your business.

You may have some difficulties to target the update component enclosed in the datatable but this can be resolved by adding something like styleClass="footerToUpdate" to your and using it in the update with update="@(.footerToUpdate)"