auto.js

    // heavily inspired https://github.com/alphagov/static/blob/master/app/assets/javascripts/search.js.erb
    $.extend($.ui.autocomplete.prototype, {
      _renderMenu: function( ul, items ) {
        var that = this,
          currentCategory = "";
        $.each( items, function( index, item ) {
          if ( item.category && item.category != currentCategory ) {
            ul.append( "<li class='ui-autocomplete-category'><span>" + item.category + "</span></li>" );
            currentCategory = item.category;
          }
          that._renderItemData( ul, item );
        });
        $(ul).find('li.post:last').addClass('last');
      },

      _renderItem: function (ul, item) {
        var list = "<li class='" + (item.type === undefined ? '' : item.type) + "'></li>",
            html;

        if (item.type == 'post') {
          html = '<strong>' + item.date + ': ' + item.label + '</strong>';
        } else {
          html = '<strong>' + item.label + '</strong>';
        }

        if (item.desc) {
          // truncate really long descriptions
          if (item.desc.length > 140) {
            item.desc = item.desc.substring(0, 120) + '&hellip;';
          }
          html += '<br><span class="excerpt">' + item.desc + '</span>';
        }
        return $(list)
          .data("item.autocomplete", item)
          .append($("<a href='" + item.url + "' class='" + item.type + "'></a>").html(html))
          .appendTo(ul);
      }
    });