I have a DataTable that creates an empty index column and the populates it with the onReady attribute once the table is loaded.

Relavent code below:

    DataTables::create(
        array(
            "name"      => "reportTable",
            "showFooter" => TRUE,
            "dataSource" => $this->dataStore("result"),
            "columns"   => array(
                "indexColumn" => ["label" => "Row", "formatValue" => function($value, $row) { return ""; }],
                ...
            ),
            "onReady" => "function() {
                    reportTable.on( 'order.dt search.dt', function () {
                        reportTable.column(0, {search:'applied', order:'applied'}).nodes().each( function (cell, i) {
                            cell.innerHTML = i+1;
                        } );
                    } ).draw();
             }",
            "plugins"    => ["Buttons"],
            "options"    => array(
                "columnDefs"=> array(
                    ["type" => "num-fmt", "targets" => [11,12,13,14,15]]
                ),
                "dom" => 'Blfrtip',
                "searching"  => TRUE,
                "paging"     => TRUE,
                "pageLength"  => 50,
                "buttons"    => [
                    array(
                        "extend"=>"csv",
                        "footer"=>"true"
                    ), 
                    array(
                        "extend"=>"excel",
                        "footer"=>"true"
                    ),
                    array(
                        'extend'=>'pdfHtml5',
                        'orientation'=>'landscape',
                        'pageSize'=>'Legal',
                        'text'=>'PDF',
                        'footer' => true
                    ), 
                    "print",
                    "colvis"
                ],
                "scrollX"    => TRUE,
                "fastRender" => TRUE
            ),

My problem is that when I export to pdf/csv/excel etc, my row column is empty I think because I'm only populating it by updating the html.

Is there a way I can populate the Row column with the correct number of current rows when an export is being called?

Thanks

I'm already using the Buttons plugin like in that example.

This is how I'm using the Buttons plugin and configuring it, taken from the original code above:

    DataTables::create(
        array(
            "name"      => "reportTable",
            "showFooter" => TRUE,
            "dataSource" => $this->dataStore("result"),
            "columns"   => array(
                               "indexColumn" => ["label" => "Row", "formatValue" => function($value, $row) { return ""; }],
            ),
            "plugins"    => ["Buttons"],
            "dom" => 'Blfrtip',            
            "options"    => array(
                                "buttons"    => [
                    array(
                        "extend"=>"csv",
                        "footer"=>"true"
                    ), 
                    array(
                        "extend"=>"excel",
                        "footer"=>"true"
                    ),
                    array(
                        'extend'=>'pdfHtml5',
                        'orientation'=>'landscape',
                        'pageSize'=>'Legal',
                        'text'=>'PDF',
                        'footer' => true
                    ), 
                    "print",
                    "colvis"
                ],

Hi, thank you this works as intended. 1 issue:

When I press the button twice without refreshing the page. The second export will treat the index value as a continuation from the previous exports. So if my first export had 1-13 rows, my second export should be the same, but instead it goes from 14 onward.

Is there a column.length() property I can check so that if the columnIndex is greater than the length/size, I can reset it?

                        'exportOptions' => [
                            "format"=> [
                                "body"=> "function ( data, row, column, node ) {
                                    if (!window.columnIndex) window.columnIndex = 0;
                                    if (column != 0) return data;
                                    else {
                                        //kind of like this 
                                        if(window.columnIndex > window.column.length){        
                                            window.columnIndex = 0;
                                        }                                        
                                        window.columnIndex += 1;
                                        return window.columnIndex;
                                    }
                                }"
                            ]
                        ]

Solved. just added a check for row

                                        if(columnIndex > row){
                                            columnIndex = 0
                                        }