​

$(document).ready(function() {

​

  function buildRow(data, rowNum, styleNum) {

    // Builds row XML.

    //Params:

    //  data: Row data.

    //  rowNum: Excel row number.

    //  styleNum: style number or empty string for no style.

    //Returns:

    //  String of XML formatted row.

    var style = styleNum ? ' s="' + styleNum + '"' : '';

    var row = '<row r="' + rowNum + '">';

​

    for (i=0; i<data.length; i++) {

    colNum = (i + 10).toString(36).toUpperCase();  // Convert to alpha

        var cr = colNum + rowNum;

        row += '<c t="inlineStr" r="' + cr + '"' + style + '>' +

              '<is>' +

                '<t>' + $('<p>' + data[i] + '</p>').text() + '</t>' + //fix to remove eventualli bad closed tags (for example input type=checkbox added to Select plugin)

              '</is>' +

            '</c>';

    }

    row += '</row>';

​

    return row;

  }

  function getTableData() {

    var ws = '';

    var rowNum = 1;

    ws += '<sheetData>';

    $("#example tbody tr").each(function(val, index){

          var arrData = [];

           if ( $(this).find("td").length ) {

             arrData = $(this).find("td").map(function (){

               return $(this).text().trim();

             }).get();

           }

          if ( $(this).find("th").length ) {

             arrData = $(this).find("th").map(function (){

               return $(this).text().trim();

             }).get();

           }

          ws += buildRow(arrData, rowNum, '');

​

          rowNum++;

        });

​

    ws += '</sheetData>';

​

    return ws;

​

  }

  function updateSheet1(xlsx) {

​

    var newSheet = '<?xml version="1.0" encoding="UTF-8" standalone="yes"?>'+

      '<worksheet xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main" xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:x14ac="http://schemas.microsoft.com/office/spreadsheetml/2009/9/ac" mc:Ignorable="x14ac">'+

      getTableData() + '</worksheet>';

​

    // Get sheet.

    var sheet = xlsx.xl.worksheets['sheet1.xml'] = $.parseXML(newSheet);

  }

​

  function getDataSrc(dt) {

    // Return the RowGroup dataSrc

    var dataSrc = dt.rowGroup().dataSrc();

​

    // If multi level use only the first level

    if ( Array .isArray( dataSrc ) ) {

      dataSrc = dataSrc[0];

    }

    return dataSrc;

  }

​

​

  var table = $('#example').DataTable({

    rowGroup: {

                startRender: null,

                endRender: function (rows, group) {

                    var sum =

                    rows

                    .data()

                    .pluck(3)

                    .reduce((a, b) => { 

                        var x = parseFloat(a) || 0;

                        var y = parseFloat(b.replace(/[^\d.-]/g, '')) || 0;

                        return x + y;

                    }, 0);

                    return $('<tr/>')

                    .append(

                        '<th>' + 'Totale di ' + group + '</th>' +

                        '<th>' + '' + '</th>' +

                      '<th>' + '' + '</th>' +

                        '<th class="text-right">' + sum + '</th>');

                },

                dataSrc: 2

            },

    order: [[2, 'asc']],

    // dom: 'Bfrtip',

        layout: {

            top2Start: 'pageLength',

            top2End: null,

            topStart: 'buttons',

            topEnd: 'search',

            bottomStart: 'info',

            bottomEnd: 'paging'

        },  

    buttons: [

      {

        extend: 'excelHtml5',

        text: 'RowGroup Excel',

​

        // Options supported by RowGroup customize function

        title: '',

        header: true,

        messageTop: 'This is the top',

        messageBottom: 'This is the bottom',

        sheetName: 'Single Sheet',

        footer: true,

​

        exportOptions: {

          modifier: {

            search: 'applied',

          }

        },

        customize: function( xlsx, button, dt ) {

​

          updateSheet1(xlsx);

​

​

        },

      }]

  });

​

​

​

});