Why does my column value not appear in jQuery datatable export? -

i have jquery datatables this:

$(document).ready(function() { $('#example1').datatable( {  "fnrowcallback" : function(nrow, adata, idisplayindex){             $("td:first", nrow).html(idisplayindex +1);            return nrow;         },  "columndefs": [ {         "paging": true,       "lengthchange": false,       "searching": true,       "ordering": true,       "info": true,       "autowidth": true,         "searchable": false,         "orderable": false,         "targets": 0     } ],  dom: 'lbfrtip',   buttons: [     'copyhtml5','excelhtml5','csvhtml5',pdfhtml5'] } ); 

in local works well:

but if export pdfhtml5, excelhtml5 , csv html, column numbering not appear.

how solve that? show column numbering in export datatables html5?

fnrowcallback meant used post processing (i.e adding additional styles or formatting content) , called whenever row displayed.

so visually see continuous numbers in column #1 output of continuous calls fnrowcallback - underlying data never changed, , therefore data missing when table exported. if want manipulate content of table - changes persistent - must go through api.

among several solutions can use createdrow callback :

createdrow: function (row, data, index) {   this.api().cell({ row:index, column:0 }).data(index+1) }     

cell().data() persistently updates underlying data; or can take advantage of render method in columndefs :

columndefs: [{   targets: 0,   autowidth: true,   searchable: false,   orderable: false,   render: function(data, type, row, info) {      return parseint(info.row)+1;   }    }]