Trying to do a sum on data tables, but its only suming first page - datatables

Question

I'm trying to sum columns in a data table. But it is only suming the first page?
The two variables Requiredone and Bookedtwo only sum the values from the first page of the data, not the entire data set :s
var sTable = $('.datatable').dataTable({
"bJQueryUI": true,
"sPaginationType": "full_numbers",
"bScrollCollapse": true,
"aaSorting": [[1, "desc"]],
"bServerSide": true,
"bProcessing": true,
"sAjaxSource": CycleTimeReport,
"aoColumns": [
{ "sName": "one", "sClass": "ellipsis" },
{ "sName": "two", "sClass": "ellipsis" }
],
"fnServerData": function (sSource, aoData, fnCallback) {
var data = new Object();
data.jsonAOData = JSON.stringify(aoData);
dataToSend = data;
$.ajax({
contentType: "application/json; charset=utf-8",
type: "POST",
url: sSource,
data: JSON.stringify(dataToSend),
success: function (msg) {
fnCallback(msg);
},
error: function (XMLHttpRequest, textStatus, errorThrown) {
if (document.Invoice.hostname == "localhost") {
alert(XMLHttpRequest.status);
alert(XMLHttpRequest.responseText);
}
}
});
},
"fnFooterCallback": function (nRow, aaData, iStart, iEnd, aiDisplay) {
var Requiredone = 0;
var Bookedtwo = 0;
for (var i = 0; i < aaData.length; i++) {
Requiredone+= aaData[i][2] * 1;
Bookedtwo += aaData[i][3] * 1;
}
},
"oLanguage": {
"sSearch": "_INPUT_"
},
"fnInitComplete": function (oSettings, json) {
},
"bSortCellsTop": true
});

Answer 1

You are using server-side processing of the data. So your datatable-object only has the data for the currently displayed page. You have to implement the sum on the server-side and add it to the JSON-response or do it in an extra ajax-request.
Another option would be to disable the server-side processing and pre-populate the table element or fill the aaData-property of the datatales-settings with a json object containing all data.