Forked Datatable with computation

sum of product of two columns https://stackoverflow.com/questions/46984173/how-to-multiply-and-sum-2-columns-of-datatables-using-jquery-datatables

by Prashant Pokhriyal

HTML

<script src="https://cdn.datatables.net/1.10.16/js/jquery.dataTables.min.js"></script>
<link rel="stylesheet" href="https://cdn.datatables.net/1.10.16/css/jquery.dataTables.min.css">
<table class="display" id="example">
  <thead>
    <tr>
      <th>ID</th>
      <th>Product Name</th>
      <th>NSP</th>
      <th>Closing Balance</th>
      <th>Date</th>
      <th>NSP * Closing Balance</th>
    </tr>
  </thead>
  <tfoot>
    <tr>
      <th>ID</th>
      <th>Product Name</th>
      <th>NSP</th>
      <th>Closing Balance</th>
      <th>Date</th>
      <th>NSP * Closing Balance</th>
    </tr>
  </tfoot>
  <tbody></tbody>
</table>
<label>Total</label>
<input type="text" id="total" class="form-control" readonly value="0.0" />

JavaScript

$(document).ready(function() {

  $.each(dataSet, function(i, it) {
    console.log(it);
    it.rowTotal = it.nsp * it.closing_balance;
  });


  // Table definition
  var dtapi = $('#example').DataTable({
    data: dataSet,
    "deferRender": false,
    "footerCallback": function(tfoot, data, start, end, display) {
      var api = this.api();
      var p = api.column(5).data().reduce(function(a, b) {
        return a + b;
      }, 0)
      $(api.column(5).footer()).html(p);
      $("#total").val(p);
    },
    "order": [1],
    "columns": [

      // rest of the columns
      {
        data: "id"
      }, {
        data: "product_name"
      }, {
        data: "nsp"
      }, {
        data: "closing_balance",
      }, {
        data: "date",
      }, {
        data: "rowTotal"
      }

    ]
  });
});

// DataTable data set used
var dataSet = [{
  "id": "Airi",
  "product_name": "Satou",
  "nsp": 230,
  "closing_balance": 23,
  "date": "28th Nov 08",
}, {
  "id": "Angelica",
  "product_name": "Ramos",
  "nsp": "191",
  "closing_balance": 131,
  "date": "9th Oct 09",
}, {
  "id": "Ashton",
  "product_name": "Cox",
  "nsp": 191,
  "closing_balance": 37,
  "date": "12th Jan 09",
}];