I noticed this question was asked, but it has not been answered correctly.

I have a datatable that has two columns start date and end date. Both contain primefaces p:calendar controls in them. I need to ensure that for each row that the date in column1 is not after the date in column2. I would like to tie this into the JSF validation framework, but I'm having trouble.

i've tried marking the datatable rowStatePreserved="true" , this allows me to get the values, but something is still wrong as when it fails, all the values in the first row overwrite all the other values. What am I doing wrong, or should I be using a completely different strategy?

xhtml code

    <h:form>
 <f:event type="postValidate" listener="#{bean.doCrossFieldValidation}"/>
       <p:dataTable id="eventDaysTable" value="#{course.courseSchedules}" var="_eventDay" styleClass="compactDataTable"
                                 >
                        <p:column id="eventDayStartColumn">
                            <f:facet name="header">
                                Start
                            </f:facet>
                            <p:calendar id="startDate" required="true"  value="#{_eventDay.startTime}" pattern="MM/dd/yyyy hh:mm a"/>
                        </p:column>
                        <p:column id="eventDayEndColumn">
                            <f:facet name="header">
                                End
                            </f:facet>
                            <p:calendar id="endDate" required="true"  value="#{_eventDay.endTime}" pattern="MM/dd/yyyy hh:mm a"/>
                        </p:column>                                        
                    </p:dataTable>
        </h:form>

validationCode

 public void doCrossFieldValidation(ComponentSystemEvent cse) {


        UIData eventsDaysStable = (UIData) cse.getComponent().findComponent("eventDaysTable");

        if (null != eventsDaysStable && eventsDaysStable.isRendered()) {

            Iterator<UIComponent> startDateCalendarIterator = eventsDaysStable.findComponent("eventDayStartColumn").getChildren().iterator();
            Iterator<UIComponent> endDateCalendarIterator = eventsDaysStable.findComponent("eventDayEndColumn").getChildren().iterator();

            while (startDateCalendarIterator.hasNext() && endDateCalendarIterator.hasNext()) {
                org.primefaces.component.calendar.Calendar startDateComponent = (org.primefaces.component.calendar.Calendar) startDateCalendarIterator.next();
                org.primefaces.component.calendar.Calendar endDateComponent = (org.primefaces.component.calendar.Calendar) endDateCalendarIterator.next();

                Date startDate = (Date) startDateComponent.getValue();
                Date endDate = (Date) endDateComponent.getValue();


                if (null != startDate && null != endDate && startDate.after(endDate)) {
                    eventScheduleChronologyOk = false;
                    startDateComponent.setValid(false);
                    endDateComponent.setValid(false);
                }

            }

            if (!eventScheduleChronologyOk) {
                showErrorMessage(ProductManagementMessage.PRODUCT_SCHEDULE_OUT_OF_ORDER);
            }

        }

    }