Rails autocomplete by data from URL

data_controller.rb

def index
    @data = Company.all
    respond_to do |format|
      format.html
      format.json { render :json => @data.to_json }
    end
  end

test.html

      <% @customer = Customer.find(1) %>
      <%= f.number_field :company_id %>
      <%= text_field_tag nil, '', :id => 'company', data: {autocomplete_source: customer_data_path(@customer, :format => :json)} %>

      <script>
          $(function () {
              var $searchBox = $('#company');
              $searchBox.autocomplete(
                      {
                          source: $('#company').data('autocomplete-source'),
                          focus: function (event, ui) {
                              $('#company').val(ui.item.company.first_name + ' ' + ui.item.company.last_name);
                              return false;
                          },
                          select: function (e, ui) {
                              e.preventDefault() // <--- Prevent the value from being inserted.
                              $(this).val(ui.item.company.first_name + ' ' + ui.item.company.last_name)
                              $('#company_id').val(ui.item.company.id)
                          }

                      }).data("autocomplete")._renderItem = function (ul, item) {
                  return $("<li></li>")
                          .data("item.autocomplete", item)
                      // For now which just want to show the person.given_name in the list.
                          .append("<a>" + item.company.first_name + ' ' + item.company.last_name + "</a>")
                          .appendTo(ul);
              };
          });
      </script>

http://stackoverflow.com/questions/3188157/how-to-set-up-jquery-ui-autocomplete-in-rails