I’m using DataTables 2.0.6 to list and export data. I am using a customise function to export files.

Everything is OK but there is br tags inside the header and cells of table (between th or td). When I click PDF button the file is coming but where there are br tags, long spaces appear instead of going to the bottom line.

Also, when I look at the codes in Chrome console, it looks like the picture below.
table header cell – th

The exported pdf file looks like below.
pdf file

My html codes:

<table class="table table-striped table-bordered border-bottom" style="width:100%"
       id="arac-datatable">
    <thead>
        <tr>
            <th>Id</th>
            <th class="text-center">
                @Html.DisplayNameFor(model => model.Plaka) <br />
                @Html.DisplayNameFor(model => model.SaseNo)
            </th>
            <th class="text-center">
                Marka - Model<br />
                Model Yılı
            </th>
            <th class="text-center">
                Müşteri
            </th>
            <th class="text-center">
                Durumu
            </th>
            <th class="text-center">
                Şube-<br />
                Kaydı Yapan-<br />
                Kayıt Tarihi
            </th>
            
            <th></th>
        </tr>
    </thead>
    <tbody>
        @foreach (var item in Model)
        {
            ...my cells...
        }
    </tbody>
</table>

My js codes:

$('#arac-datatable').DataTable({

        dom: 'Bfrtip',
        fixedHeader: true,
        paging: true,
        pageLength: 50,
        order: [[0, 'desc']],
        ordering: true,
        buttons: {
            dom: {
                button: {
                    tag: 'button',
                    className: ''
                }
            },
            buttons: [{
                extend: 'pdfHtml5',
                className: 'btn btn-sm btn-warning',
                titleAttr: 'PDF Olarak İndir',
                text: '<i class="fa fa-file-pdf-o"></i> PDF',
                filename: 'pdf-export',
                extension: '.pdf',
                exportOptions: {
                    columns: [1, 2, 3, 4],
                    search: 'applied',
                    order: 'applied'
                },
                customize: function (doc) {
                    doc.content.splice(0, 1);
                    doc.pageMargins = [40, 80, 40, 40];
                    doc.defaultStyle.fontSize = 10;
                    doc.styles.tableHeader.fontSize = 10;
                    
                    doc.content[0].table.widths = ['20%', '30%', '30%', '20%'];

                    doc.styles.tableHeader = {
                        color: 'navy',
                        alignment: 'center'
                    };

                    doc['header'] = (function () {
                        return {
                            columns: [
                                {
                                    image: logo
                                },
                                {
                                    alignment: 'center',
                                    italics: true,
                                    text: dtableheaderorta,
                                    fontSize: 18,
                                    margin: [10, 0],
                                    width:400
                                },
                                {
                                    alignment: 'right',
                                    fontSize: 10,
                                    text: dtableheadersag
                                }
                            ],
                            margin: 30
                        }
                    }); 

                    doc['footer'] = (function (page, pages) {
                        return {
                            columns: [
                                {
                                    alignment: 'left',
                                    text: dtablefootersol
                                },
                                {
                                    alignment: 'right',
                                    text: ['Sayfa ', { text: page.toString() }, ' / ', { text: pages.toString() }]
                                }
                            ],
                            margin: [30, 0]
                        }
                    });

                    for (var x = 2; x < doc.content[0].table.body.length; x+=2) {
                        doc.content[0].table.body[x].forEach(function (h) {
                            h.fillColor = dtableRowEvenBg;
                            
                        });
                    }

                    var objLayout = {};
                    objLayout['width'] = function (i) { return 800; };
                    objLayout['hLineWidth'] = function (i) { return .5; };
                    objLayout['vLineWidth'] = function (i) { return .5; };
                    objLayout['hLineColor'] = function (i) { return '#aaa'; };
                    objLayout['vLineColor'] = function (i) { return '#aaa'; };
                    objLayout['paddingLeft'] = function (i) { return 4; };
                    objLayout['paddingRight'] = function (i) { return 4; };
                    doc.content[0].layout = objLayout;
                }
            },

            {
                extend: 'excel',
                className: 'btn btn-sm btn-success',
                titleAttr: 'Excel Tablosu İndir',
                text: '<i class="fa fa-file-excel-o"></i> EXCEL',
                filename: 'excel-export',
                extension: '.xlsx',
                exportOptions: {
                    columns: [1, 2, 3, 4],
                    search: 'applied',
                    order: 'applied'
                }
            },
            {
                extend: 'csv',
                className: 'btn btn-sm btn-success',
                titleAttr: 'Excel CSV Formatı.',
                text: '<i class="fa fa-file-excel-o"></i> CSV',
                filename: 'csv-excel-export',
                extension: '.csv',
                exportOptions: {
                    columns: [1, 2, 3, 4],
                    search: 'applied',
                    order: 'applied'
                }
            },
            {
                extend: 'copy',
                className: 'btn btn-sm btn-light',
                titleAttr: 'Tabloyu Kopyala',
                text: '<i class="fa fa-copy"></i> Kopyala',
                exportOptions: {
                    columns: [1, 2, 3, 4],
                    search: 'applied',
                    order: 'applied',
                }
            },
            {
                extend: 'print',
                className: 'btn btn-sm btn-dark',
                titleAttr: 'Tabloyu Yazdır',
                text: '<i class="fa fa-print"></i> Yazdır',
                exportOptions: {
                    columns: [1, 2, 3, 4],
                    search: 'applied',
                    order: 'applied',
                }
            }]
        },
        
        language: {
            url: dtableLangUrl
        },
        columnDefs: [
            {
                target: 0,
                visible: false,
                searchable: false
            }
        ]
    });

I tried lots of things. For example:

var rowsss = doc.content[0].table.body;
                    for (i = 0; i < rowsss.length; i++) {
                        /*for (var j = 0; j < rowsss.columns.length; j++) {

                        }*/

                        rowsss[i][1].text = rowsss[i][1].text.replace('t', 'n');
                        rowsss[i][1].text = rowsss[i][1].text.replace('r', 'n');
                        rowsss[i][1].text = rowsss[i][1].text.replace('<br/>', 'n');
                        rowsss[i][1].text = rowsss[i][1].text.replace('<br>', 'n');
                        rowsss[i][1].text = rowsss[i][1].text.replace('<br />', 'n');
                    }

but anything worked.