page number not working in datatable export to pdf

Question

I am trying to add page number in datatble pdf export, I got code from its official site after adding this code pdf button got disappearing and getting 'Uncaught ReferenceError: doc is not defined at HTMLDocument' error in console.

$('#table2').DataTable({
    
    dom: 'Bfrtip',
   
    buttons: [
         
        {
            extend: 'pdfHtml5',
            title: 'Data export',
            filename: 'dt_custom_pdf',
            pageSize: 'A4',
                exportOptions: {
                    columns: ':visible',
                    search: 'applied',
                    order: 'applied'
                },
           
            
        },
       doc['footer']=(function(page, pages) {
        return {
        columns: [
        'Left part of footer',
            {
                alignment: 'right',
                text: [
                    { text: page.toString(), italics: true },
                    ' of ',
                    { text: pages.toString(), italics: true }
                ]
            }
        ],
        margin: [10, 0]
        }
        });
    ]
   });

Answer 1

You did not define customize function to dataTable that why getting doc error you need to change

$('#table2').DataTable({
    
    dom: 'Bfrtip',
   
    buttons: [
         
        
        {
        extend: 'pdfHtml5',
        text: 'Pdf',
        filename: 'dt_custom_pdf',
        pageSize: 'A4',
            exportOptions: {
                columns: ':visible',
                search: 'applied',
                order: 'applied'
            },
        customize: function ( doc ) {
            doc['footer']=(function(page, pages) {
                return {
                columns: [
                
                {
                alignment: 'center',
                text: [
                { text: page.toString(), italics: true },
                ' of ',
                { text: pages.toString(), italics: true }
                ]
                }
                ],
                margin: [10, 0]
                }
                });
            
        }
    }
    
    ]
   });