Teton-Coder Teton-Coder - 29 days ago 18
Javascript Question

How to export data from table to csv file using jquery

I'm trying to export from a data table into a CSV file. Here is my whole function. It downloads a file, but it shows the whole code for the table and not separating any of the data out. When I say whole code I mean everything within 'table /table'

function displayDataTable(index){
$("#pageOverlay").empty();
html = "<div id='volumeChartDiv'><h4>Data Table</h4><table id='dataTable' class='table table-bordered table-striped dataTable' role='grid'><thead><tr role='row'><th>header1</th><th>header2</th><th>header3</th></tr></thead><tbody><tr><td>cell1-1</td><td>cell1-2</td><td>cell1-3</td></tr><tr><td>bell2-1</td><td>bell2-2</td><td>bell2-3</td></tr><tr><td>fell3-1</td><td>fell3-2</td><td>fell3-3</td></tr></tbody></table><input type='button' value='Close' onclick='closeOverlay()'>&nbsp;&nbsp;<input type='button' id='exportDataTable' value='Export Table'></div>";
$("#pageOverlay").html(html);
// export data function
$("#exportDataTable").click(function (e) {
window.open('data:application/vnd.ms-excel,' + $('.dataTable').html());
e.preventDefault();
});
openOverlay();
}

Answer

CSV format cannot accept $('.dataTable').html() as .html() is not a structured data, it's not even data, just a silly hmtl.

You have to get data from your table, make a string representing CSV format, and download it, As you don't show your table data structure here's working demo below

$('#export').click(function() {
  var titles = [];
  var data = [];

  /*
   * Get the table headers, this will be CSV headers
   * The count of headers will be CSV string separator
   */
  $('.dataTable th').each(function() {
    titles.push($(this).text());
  });

  /*
   * Get the actual data, this will contain all the data, in 1 array
   */
  $('.dataTable td').each(function() {
    data.push($(this).text());
  });
  
  /*
   * Convert our data to CSV string
   */
  var CSVString = prepCSVRow(titles, titles.length, '');
  CSVString = prepCSVRow(data, titles.length, CSVString);

  /*
   * Make CSV downloadable
   */
  var downloadLink = document.createElement("a");
  var blob = new Blob(["\ufeff", CSVString]);
  var url = URL.createObjectURL(blob);
  downloadLink.href = url;
  downloadLink.download = "data.csv";

  /*
   * Actually download CSV
   */
  document.body.appendChild(downloadLink);
  downloadLink.click();
  document.body.removeChild(downloadLink);
});

   /*
* Convert data array to CSV string
* @param arr {Array} - the actual data
* @param columnCount {Number} - the amount to split the data into columns
* @param initial {String} - initial string to append to CSV string
* return {String} - ready CSV string
*/
function prepCSVRow(arr, columnCount, initial) {
  var row = ''; // this will hold data
  var delimeter = ','; // data slice separator, in excel it's `;`, in usual CSv it's `,`
  var newLine = '\r\n'; // newline separator for CSV row

  /*
   * Convert [1,2,3,4] into [[1,2], [3,4]] while count is 2
   * @param _arr {Array} - the actual array to split
   * @param _count {Number} - the amount to split
   * return {Array} - splitted array
   */
  function splitArray(_arr, _count) {
    var splitted = [];
    var result = [];
    _arr.forEach(function(item, idx) {
      if ((idx + 1) % _count === 0) {
        splitted.push(item);
        result.push(splitted);
        splitted = [];
      } else {
        splitted.push(item);
      }
    });
    return result;
  }
  var plainArr = splitArray(arr, columnCount);
  // don't know how to explain this
  // you just have to like follow the code
  // and you understand, it's pretty simple
  // it converts `['a', 'b', 'c']` to `a,b,c` string
  plainArr.forEach(function(arrItem) {
    arrItem.forEach(function(item, idx) {
      row += item + ((idx + 1) === arrItem.length ? '' : delimeter);
    });
    row += newLine;
  });
  return initial + row;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<button id="export">export</button>

<table class="dataTable">
  <tr>
    <th>Company</th>
    <th>Contact</th>
    <th>Country</th>
  </tr>
  <tr>
    <td>Alfreds Futterkiste</td>
    <td>Maria Anders</td>
    <td>Germany</td>
  </tr>
  <tr>
    <td>Centro comercial Moctezuma</td>
    <td>Francisco Chang</td>
    <td>Mexico</td>
  </tr>
  <tr>
    <td>Ernst Handel</td>
    <td>Roland Mendel</td>
    <td>Austria</td>
  </tr>
  <tr>
    <td>Island Trading</td>
    <td>Helen Bennett</td>
    <td>UK</td>
  </tr>
  <tr>
    <td>Laughing Bacchus Winecellars</td>
    <td>Yoshi Tannamuri</td>
    <td>Canada</td>
  </tr>
  <tr>
    <td>Magazzini Alimentari Riuniti</td>
    <td>Giovanni Rovelli</td>
    <td>Italy</td>
  </tr>
</table>

If you find any bugs, comment below, i'll fix them

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