Custom Max aggregate on a Date column in kendo grid - kendo-grid

Question

I am trying to perform a custom max aggregate on a date column in a kendo grid and display it using the ClientFooterTemplate at the bottom of the column. I want to calculate the max aggregate only when all dates under the date column have values.
#(Html.Kendo().Grid<InstallerWrapper>().Name(#"InstallerTable")
.DataSource(dataSource => dataSource
.Ajax()
.Model(m => m.Id(o => o.InstallerId))
.Read(read => read
.Action("GetInstaller", "DataProvider", new { orderId = Model.OrderId })
.Type(HttpVerbs.Post))
.Aggregates(aggregates =>
{
aggregates.Add(o => o.SurveyReceivedDate).Max();
})
.PageSize(20)
)
.Columns(columns =>
{
columns.Bound(o => o.InstallerId).Title("Installer")
.ClientTemplate("#=VendorName#")
.Filterable(false).Width(225)
.ClientFooterTemplate("All")
.Sortable(false);
columns.Bound(o => o.SurveyReceivedDate).Title("Survey Received")
.HeaderHtmlAttributes(new { style = "overflow: visible; white-space: normal" })
.Filterable(false)
.ClientTemplate("#=SurveyReceivedDate#")
.ClientFooterTemplate("#=kendo.toString(kendo.parseDate(max),'MM/dd/yyyy')#")
.Sortable(false);
})
.Selectable()
.Sortable()
.Filterable()
.Pageable(p => p.Refresh(true)))

Answer 1

Use a function in the ClientFooterTemplate for the column to get this.
columns.Bound(o => o.SurveyReceivedDate).Title("Survey Received").HeaderHtmlAttributes(new { style = "overflow: visible; white-space: normal" }).Filterable(false)
.ClientTemplate("#=SurveyReceivedDate#")
.ClientFooterTemplate("#if (getMaxDateText()){# #} else{# #=kendo.toString(kendo.parseDate(max),'MM/dd/yyyy')# #} #")
.FooterHtmlAttributes(new { style =" color: red "})
.Sortable(false);
Javascript Function:
<script>
function getMaxDateText() {
var surveyReceivedArray = [];
var data = $("#InstallerTable").data("kendoGrid").dataSource._data;
for (var i = 0; i < data.length; i++) {
surveyReceivedArray.push(data[i].SurveyReceivedDate);
}
var isAtLeastOneNull = surveyReceivedArray.some(function (o) { return o === null; });
if (isAtLeastOneNull) {
return true;
}
else {
return false;
}
}
</script>