Clear Select2 before send ajax

Question

How can I clear the last results, before Select2 starts a new ajax-call? (Without changing the original select2-files)

To reproduce:

1. Select2 with ajax-function.
2. Search anything.
3. Search with other term.
4. The old results of step 2 are still visible unitl the ajax-query of step 3 is ready.

Answer 1

Inside ajax data handler you can clear items:

ajax: {
    type: "POST",
    url: '/echo/json/',
    dataType: 'json',
    data: function(params){
        console.log("ajax");
      // reset selection
      $('.select').val(null).trigger('change');
      var query = {
        search: params.term,
        items: data
      };
      return { json: JSON.stringify( query ) }
    },
    processResults: function (data, page) { 
        return { results: data.items };
    },
}

Here is a jsfiddle: https://jsfiddle.net/beaver71/jb07ehpq/