JSFiddle - React, Tailwind, and code Playground

by anoopsuda

HTML

<div class="container">
        <h2 class="text-center mt-4 mb-4">Convert Excel to HTML Table using JavaScript</h2>
        <div class="card">
            <div class="card-header"><b>Select Excel File</b></div>
            <div class="card-body">
                
                <input type="file" id="excel_file" />

            </div>
        </div>
        <div id="excel_data" class="mt-5"></div>
    </div>

JavaScript

const excel_file = document.getElementById('excel_file');

excel_file.addEventListener('change', (event) => {

    if(!['application/vnd.openxmlformats-officedocument.spreadsheetml.sheet', 'application/vnd.ms-excel'].includes(event.target.files[0].type))
    {
        document.getElementById('excel_data').innerHTML = '<div class="alert alert-danger">Only .xlsx or .xls file format are allowed</div>';

        excel_file.value = '';

        return false;
    }

    var reader = new FileReader();

    reader.readAsArrayBuffer(event.target.files[0]);

    reader.onload = function(event){

        var data = new Uint8Array(reader.result);

        var work_book = XLSX.read(data, {type:'array'});

        var sheet_name = work_book.SheetNames;

        var sheet_data = XLSX.utils.sheet_to_json(work_book.Sheets[sheet_name[0]], {header:1});

        if(sheet_data.length > 0)
        {
            var table_output = '<table class="table table-striped table-bordered">';

            for(var row = 0; row < sheet_data.length; row++)
            {

                table_output += '<tr>';

                for(var cell = 0; cell < sheet_data[row].length; cell++)
                {

                    if(row == 0)
                    {

                        table_output += '<th>'+sheet_data[row][cell]+'</th>';

                    }
                    else
                    {

                        table_output += '<td>'+sheet_data[row][cell]+'</td>';

                    }

                }

                table_output += '</tr>';

            }

            table_output += '</table>';

            document.getElementById('excel_data').innerHTML = table_output;
        }

        excel_file.value = '';

    }

});