Make select2 4.0 above tags works with text input field

select2_input_tags.js

// https://gist.github.com/lingceng/d1cd5ca5db9a777b31487769242c422f
// See the issue here: https://github.com/select2/select2/issues/3022

function select2InputTags(queryStr) {
  var $input = $(queryStr)

  var $select = $('<select class="'+ $input.attr('class') + '" multiple="multiple"><select>')
  if ($input.val() != "") {
    $input.val().split(',').forEach(function(item) {
      $select.append('<option value="' + item + '" selected="selected">' + item + '</option>')
    });
  }
  $select.insertAfter($input)
  $input.hide()

  $select.change(function() {
     $input.val(($select.val() || [""]).join(","));
  });

  return $select;
}