DataTables.Net To Give Sum For 7 Columns

Question

From reading the DataTables.net wiki I found how to add a Total to one column, column 4 in the syntax below, so I am sure someone with extensive JQuery experience could easily adapt to show a total for columns 6 - 12 for me.

This is the base set-up to add a total for column 4 - what would be altered to add a total for an additional column?

https://datatables.net/examples/advanced_init/footer_callback.html

    $(document).ready(function() {
    $('#example').DataTable( {
        "footerCallback": function ( row, data, start, end, display ) {
            var api = this.api(), data;

            // Remove the formatting to get integer data for summation
            var intVal = function ( i ) {
                return typeof i === 'string' ?
                    i.replace(/[\$,]/g, '')*1 :
                    typeof i === 'number' ?
                        i : 0;
            };

            // Total over all pages
            total = api
                .column( 4 )
                .data()
                .reduce( function (a, b) {
                    return intVal(a) + intVal(b);
                }, 0 );

            // Total over this page
            pageTotal = api
                .column( 4, { page: 'current'} )
                .data()
                .reduce( function (a, b) {
                    return intVal(a) + intVal(b);
                }, 0 );

            // Update footer
            $( api.column( 4 ).footer() ).html(
                '$'+pageTotal +' ( $'+ total +' total)'
            );
        }
    } );
} );

Answer 1

Some quick refactoring allows for a callable function with any column number. You will notice that I:

1. wrapped what used to work for column 4 into a function with one parameter representing the column to sum up colNum.
2. I then replaced all occurrences to 4 within the new function to colNum and
3. proceeded to call the newly created function after it's definition.

$(document).ready(function() {
  $('#example').DataTable({
    "footerCallback": function(row, data, start, end, display) {
      var api = this.api(),
        data;

      // Remove the formatting to get integer data for summation
      var intVal = function(i) {
        return typeof i === 'string' ?
          i.replace(/[\$,]/g, '') * 1 :
          typeof i === 'number' ?
          i : 0;
      };
      var totalColumn = function(colNum) {
        // Total over all pages
        total = api
          .column(colNum)
          .data()
          .reduce(function(a, b) {
            return intVal(a) + intVal(b);
          }, 0);

        // Total over this page
        pageTotal = api
          .column(colNum, {
            page: 'current'
          })
          .data()
          .reduce(function(a, b) {
            return intVal(a) + intVal(b);
          }, 0);

        // Update footer
        $(api.column(colNum).footer()).html(
          '$' + pageTotal + ' ( $' + total + ' total)'
        );
      }
      totalColumn(6);
      totalColumn(7);
      //...snip...
    }
  });
});