Cascading Dropdown on Filters

Cascading Dropdown on Filters (jquery DataTable)

by Shrikrishna Gupta

HTML

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/[email protected]/css/modern/tail.select-light-feather.min.css">
<link rel="stylesheet" href="https://cdn.datatables.net/1.10.19/css/jquery.dataTables.min.css">
<script src="https://code.jquery.com/jquery-3.3.1.js"></script>
<script src="https://cdn.datatables.net/1.10.19/js/jquery.dataTables.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/[email protected]/js/tail.select.js"></script>
<table id="example" class="display" cellspacing="0" width="100%">
  <thead>
    <tr>
      <th class="filterhead">Name</th>
      <th class="filterhead">Position</th>
      <th class="filterhead">Office</th>
      <th class="filterhead">Age</th>
      <th class="filterhead">Start date</th>
      <th class="filterhead">Salary</th>
    </tr>
  </thead>

  <tfoot>
    <tr>
      <th>Name</th>
      <th>Position</th>
      <th>Office</th>
      <th>Age</th>
      <th>Start date</th>
      <th>Salary</th>
    </tr>
  </tfoot>
  <tbody>
    <tr>
      <td>Tiger Nixon</td>
      <td>System Architect</td>
      <td>Edinburgh</td>
      <td>61</td>
      <td>2011/04/25</td>
      <td>$320,800</td>
    </tr>
    <tr>
      <td>Garrett Winters</td>
      <td>Accountant</td>
      <td>Tokyo</td>
      <td>63</td>
      <td>2011/07/25</td>
      <td>$170,750</td>
    </tr>
    <tr>
      <td>Ashton Cox</td>
      <td>Junior Technical Author</td>
      <td>San Francisco</td>
      <td>66</td>
      <td>2009/01/12</td>
      <td>$86,000</td>
    </tr>
    <tr>
      <td>Cedric Kelly</td>
      <td>Senior Javascript Developer</td>
      <td>Edinburgh</td>
      <td>22</td>
      <td>2012/03/29</td>
      <td>$433,060</td>
    </tr>
    <tr>
      <td>Airi Satou</td>
      <td>Accountant</td>
      <td>Tokyo</td>
      <td>33</td>
      <td>2008/11/28</td>
      <td>$162,700</td>
    </tr>
    <tr>
      <td>Brielle Williamson</td>
      <td>Integration Specialist</td>
      <td>New York</td>
      <td>61</td>
     ...

JavaScript

$(document).ready(function() {
    var table = $('#example').DataTable({
        initComplete: function() {
            this.api().columns().every(function() {
                var column = this;
                var select = $('<select class ="filter"></select>')
                             .appendTo($(column.footer()).empty())
                             .tailselect({ deselect: true, width: 180 });
                             
                select.on("change", function(){
                    var val = $.fn.dataTable.util.escapeRegex(this.value());
                    column.search(val? ('^' + val + '$'): '', true, false).draw();
                });
                
                column.data().unique().sort().each(function(d, j) {
                    select.options.add(d, d, '#');
                });
                select.query();
            });
        }
    });
    table.on('draw', function() {
        table.columns().indexes().each(function(idx) {
            var select = $(table.column(idx).footer()).find('select').tailselect();

            if (select.value() === null) {
                select.reload();
                
                table.column(idx, {
                    search: 'applied'
                }).data().unique().sort().each(function(d, j) {
                    select.options.add(d, d);
                });

                select.query();
            }
        });
    });
});