title: Select2 makes an ajax call each time I open it
body: <p>I'm trying to populate a select2 control only when users open it, but it makes lots of ajax call, and for lots of ajax calls I mean it continue sending post request, also I can't event close the select2, what I'm doing wrong? Thanks in advance.</p>
  
  <pre><code> $('#select').select2().one('select2-open', function(){
  $.ajax({
      url: '/url',
      data: {
          data: data
      },
      type: "POST"
  }).done(function (data) {
      var optionhtml = "&lt;option value=''&gt;&lt;/option&gt;";
      for (var i = 0; i &lt; data.length; i++) {
          optionhtml += "&lt;option value='" + data[i].field_id + "'&gt;" + data[i].field + "&lt;/option&gt;";
      }
      $("#select").html(optionhtml);
      $("#select").select2({
          allowClear: true
      });
      $("#select").select2('open');
  });
  </code></pre>
  
  <p>});</p>