Answers

• rf1234 Posts: 3,026Questions: 88Answers: 422

  April 2020 edited April 2020 Answer ✓

  You could try orthogonal data using type === 'export'
  https://datatables.net/extensions/buttons/examples/html5/outputFormat-orthogonal.html

  If that is not possible for the footer you can try export options
  https://datatables.net/extensions/buttons/examples/html5/outputFormat-function

  https://datatables.net/reference/button/excelHtml5 and more details about export options here
  https://datatables.net/reference/api/buttons.exportData()

  You can also access the footer:
  

  This should show you how to do this ... more or less:

  //custom button for cashflow csv generation
  $.fn.dataTable.ext.buttons.csvCashFlow = {
      extend: 'csv', fieldSeparator: csvSep, charset: 'UTF-8', bom: true,
                     filename: cashFlowTitle,
      exportOptions: {
          columns: function(column, data, node) {
              if (column > 17) {
                  return false;
              }
              return true;
          },
          modifier: { selected: null }, //make sure all records show up!!
          format: {
              body: function ( data, row, column, node ) {
                  if (typeof data !== 'undefined') {
                      if (data != null) {  
                          var i=0;  //get rid of the currency ISO codes
                          while ( cur[i] ) {
                              if ( data.search( cur[i] ) > -1 )   {
                                  data = data.split(cur[i]).join("");
                              }
                              i++;
                          }
                          //rate must be adjusted to fraction to be able to calculate
                          if (column == 4 || column == 16) {
                              if (data !== '') {
                                  if (lang === 'de') {
                                      //replace the only comma with a period
                                      data = data.toString().replace(",", ".");
                                  }
                                  data = data / 100;
                                  if (lang === 'de') {
                                      //replace the only period with a comma                                        
                                      data = data.toString().replace(".", ",");
                                  }
                              }
                          }
                      }
                  }
                  return data;
              },
              header: function ( data, column ) {
                  return data;
              },
              footer: function ( data, column ) {
                  //do something to modify the data
                  return data;
              }
          }
      }
  };
  

  And here is a thread dealing with the footer in export options as well:
  https://datatables.net/forums/discussion/comment/106393/#Comment_106393
• georgeforster Posts: 21Questions: 9Answers: 1

  April 2020

  I have updated the exportoptions section to be this

  exportOptions: 
  {
      stripHtml: true,
      columns: [0, 1, 2, 3, 4, 5, 6],
      format: 
      {   body: function (data, row, column, node)
          {
              return data;
          },
          header: function( data, row, column, node)
          {
              return data;
          },
          footer: function ( data, row, column, node ) 
          {
              if (column == 3)
              {
                  data = "3";
              }
              else if (column == 1)
              {
                  data = "1";
              }
              else
              {
                  data = "*";
              }                                           
              return data;
          }
      }
  }
  

  However I only see the * character in the footer. I also tried with just the data and column as parameters, but that didn't work either. I'm thinking that column is not an integer, although your example implies that it is for the body section. Is the footer section different

  The test case has been updated
• georgeforster Posts: 21Questions: 9Answers: 1

  April 2020

  OK, found out the issue,

  The footer parameters are only data and column, rather than data, row, column, node that one of the linked examples suggested