问如何使用jspdf将HTML表格导出为pdf？

<script type="text/javascript">
    function demo1() {
        $(function () {
            var specialElementHandlers = {
                '#editor': function (element,renderer) {
                    return true;
                }
            };
         $('#cmd').click(function () {
                var doc = new jsPDF();
                doc.fromHTML($('#htmlTableId').html(), 15, 15, {
                    'width': 170,'elementHandlers': specialElementHandlers
                });
                doc.save('sample-file.pdf');
            });  
        }); 
    }
</script>
`