osem/app/views/shared/_user_selectize.html.haml

:javascript
  $(document).ready(function() {
    $('#users_selectize').selectize({
      persist: false,
      create: false,
      valueField: 'id',
      labelField: 'username',
      searchField: 'username',
      load: function(query, callback) {
        if (!query.length) return callback();
        $.ajax({
          url: "#{search_users_path}.json",
          type: 'GET',
          dataType: 'json',
          data: {
            query: query,
          },
          error: function(res) {
            console.log("selectize error");
            callback();
          },
          success: function(res) {
            console.log("selectize success");
            // console.log(res);
            callback(res.users);
          }
        });
      }
    });
  });