jquery datatables - sum columns within a group

Question

I'm soooo close to getting exactly what I want, just need a little help.

I have grouping working. Now I want to sum the columns for each group and display the total in the group header. Here's a jsfiddle of it since it easier to show what I'm trying to do:

http://jsfiddle.net/RgKPZ/123/

The relevant code:

$(function() {
            oTable = $('#job_history').dataTable({

                "aoColumnDefs": [
                    { "bVisible": false, "aTargets": [ 4,5,6 ] },
                ],
                "aLengthMenu": [[10, 25, 50, -1], ["Show 10 entries", "Show 25 entries", "Show 50 entries", "Show all entries"]], // options in the show rows selector
                "iDisplayLength" : -1, // show all rows by default
                "aaSortingFixed": [[ 5, 'asc' ]],
                "aaSorting": [[ 5, 'asc' ]],
                "bJQueryUI": true,
                "sDom": '<flip>', // filter, length, info, pagination

                "oLanguage": {
                    "sSearch": "", // label for search field - see function below for setting placeholder text
                    "sLengthMenu": "_MENU_", // label for show selector { "sLengthMenu": "Display _MENU_ jobs" }
                    "sInfo": "Showing _START_ to _END_ of _TOTAL_ entries.", // string for information display
                    "sInfoEmpty": "No entries to show", // what to show when info is empty
                    "sInfoFiltered": " (Filtering from _MAX_ entries.)",
                    "sEmptyTable": "There are no entries matching the search criteria.", // shown when table is empty, regardless of filtering
                    "sZeroRecords": "", // shown when nothing is left after filtering
                },

                "fnDrawCallback": function ( oSettings ) {
                    if ( oSettings.aiDisplay.length == 0 )
                    {
                        return;
                    }

                    var nTrs = $('#job_history tbody tr'); // get all table rows
                    var iColspan = nTrs[0].getElementsByTagName('td').length;
                    var sLastGroup = "";
                    var summed_minutes = 0;

                    for (var i = 0; i < nTrs.length; i++)
                    {
                        var iDisplayIndex = oSettings._iDisplayStart + i;
                        var sGroup = oSettings.aoData[ oSettings.aiDisplay[iDisplayIndex] ]._aData[ 5 ];

                        if ( sGroup != sLastGroup )
                        {
                            var nGroup = document.createElement( 'tr' );
                            var nCell = document.createElement( 'td' );
                            nCell.colSpan = iColspan;
                            nCell.className = "group";

                            summed_minutes += oSettings.aoData[ oSettings.aiDisplay[iDisplayIndex] ]._aData[ 7 ];
                            nCell.innerHTML = sGroup + summed_minutes;
                            nGroup.appendChild( nCell );
                            nTrs[i].parentNode.insertBefore( nGroup, nTrs[i] );
                            sLastGroup = sGroup;
                        }
                    }
                }

            });

        });

The only problem is that the columns I want to sum aren't being added together. The values are being displayed, but like a string instead of adding together like numbers. Also, not all of the values are even being displayed as a string - there are repeats going on. I tried converting using Number() and parseInt() but no luck. I'm trying to put this into the callback function (like the grouping function) so that the values will be summed after each table filter, too.

I'm sure I just have a variable wrong or in the wrong place or something, but I just can't figure it out. Frustratingly close! :-(

TIA, Matt

Answer 1

Try this...

Change all <div id='group_sum'>0</div> to <div class='group_sum'></div> because id should be unique. so use class

See it in fiddle

  $(function() {
    var oTable = $('#job_history').dataTable({
        "aoColumnDefs": [{ "bVisible": false, "aTargets": [4, 5, 6]}],
        "aLengthMenu": [[10, 25, 50, -1], ["Show 10 entries", "Show 25 entries", "Show 50 entries", "Show all entries"]],
        "iDisplayLength": -1,
        "aaSortingFixed": [[5, 'asc']],
        "aaSorting": [[5, 'asc']],
        "bJQueryUI": true,
        "sDom": '<flip>',
        "fnDrawCallback": function(oSettings) {
            if (oSettings.aiDisplay.length == 0) {
                return;
            }

            // GROUP ROWS
            var nTrs = $('#job_history tbody tr');
            var iColspan = nTrs[0].getElementsByTagName('td').length;
            var sLastGroup = "";

            for (var i = 0; i < nTrs.length; i++) {
                var iDisplayIndex = oSettings._iDisplayStart + i;
                var sGroup = oSettings.aoData[oSettings.aiDisplay[iDisplayIndex]]._aData[5];

                if (sGroup != sLastGroup) {
                    var nGroup = document.createElement('tr');
                    var nCell = document.createElement('td');
                    nCell.colSpan = iColspan;
                    nCell.className = "group";
                    nCell.innerHTML = sGroup;
                    nGroup.appendChild(nCell);
                    nTrs[i].parentNode.insertBefore(nGroup, nTrs[i]);
                    sLastGroup = sGroup;
                }
            }
            //-------------------------------------------------
            // SUM COLUMNS WITHIN GROUPS
            var total = 0;
            $("#job_history tbody tr").each(function(index) {
                if ($(this).find('td:first.group').html()) {
                    total = 0;
                } else {
                    total = parseFloat(total) + parseFloat(this.cells[4].innerHTML);
                    $(this).closest('tr').prevAll('tr:has(td.group):first').find("div").html(total);
                }
            });
            //-------------------------------------------------
        }
    });
});