jquery sort table without plugin-CodePudding

Hello i'm using jquery to sort a table on click on the "th" tag, my code working well but only with numbers and words, but not with the date, is there anything wrong in the code :

<table>
  <thead>
    <tr>
      <th>head1</th>
      <th>head2</th>
      <th>head3</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>1</td>
      <td>b</td>
      <td>13/03/1998</td>
    </tr>
    <tr>
      <td>3</td>
      <td>a</td>
      <td>02/01/2005</td>
    </tr>
    <tr>
      <td>2</td>
      <td>c</td>
      <td>10/12/2022</td>
    </tr>
  </tbody>
</table>

and the js :

$(document).on('click', 'th', function() {
  var table = $(this).parents('table').eq(0);
  var rows = table.find('tr:gt(0)').toArray().sort(comparer($(this).index()));
  this.asc = !this.asc;
  if (!this.asc) {
    rows = rows.reverse();
  }
  table.children('tbody').empty().html(rows);
});

function comparer(index) {
  return function(a, b) {
    var valA = getCellValue(a, index),
      valB = getCellValue(b, index);
    return $.isNumeric(valA) && $.isNumeric(valB) ?
      valA - valB : valA.localeCompare(valB);
  };
}

function getCellValue(row, index) {
  return $(row).children('td').eq(index).text();
}

thank you in advance

CodePudding user response：

As currently written, your code is treating each date as a string, and sorting it alphanumerically instead of chronologically.

Assuming your dates all use the format dd/mm/yyyy, then you can re-arrange the date strings into a numeric format yyyymmdd, which is suitable for sorting:

function reformatDate(val) {
  return val.substring(6, 10)   val.substring(3, 5)   val.substring(0, 2);
}

You can use this function in your comparer() function, by checking the column index:

if ( index === 2 ) {
  valA = reformatDate(valA);
  valB = reformatDate(valB);
  console.log(valA, valB);
}

A demo:

$(document).on('click', 'th', function() {
  var table = $(this).parents('table').eq(0);
  var rows = table.find('tr:gt(0)').toArray().sort(comparer($(this).index()));
  this.asc = !this.asc;
  if (!this.asc) {
    rows = rows.reverse();
  }
  table.children('tbody').empty().html(rows);
});

function comparer(index) {
  return function(a, b) {
    var valA = getCellValue(a, index),
      valB = getCellValue(b, index);
    if ( index === 2 ) {
      valA = reformatDate(valA);
      valB = reformatDate(valB);
      //console.log(valA, valB);
    }
    return $.isNumeric(valA) && $.isNumeric(valB) ?
      valA - valB : valA.localeCompare(valB);
  };
}

function getCellValue(row, index) {
  return $(row).children('td').eq(index).text();
}

function reformatDate(val) {
  return val.substring(6, 10)   val.substring(3, 5)   val.substring(0, 2);
}

<!doctype html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>demo</title>

<script src="https://code.jquery.com/jquery-3.6.0.min.js" integrity="sha256-/xUj 3OJU5yExlq6GSYGSHk7tPXikynS7ogEvDej/m4=" crossorigin="anonymous"></script>

  <style>
  </style>

</head>

<body>

<table>
  <thead>
    <tr>
      <th>head1</th>
      <th>head2</th>
      <th>head3</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>1</td>
      <td>b</td>
      <td>13/03/1998</td>
    </tr>
    <tr>
      <td>3</td>
      <td>a</td>
      <td>02/01/2005</td>
    </tr>
    <tr>
      <td>2</td>
      <td>c</td>
      <td>10/12/2022</td>
    </tr>
  </tbody>
</table>


</body>

</html>

This approach takes your constraint "without plugin" to mean without any additional plugins except for jQuery, which is implied by the code in your question.