Ajax magic does not work - Book Agil Development with Rails

Ajax magic does not work - Book Agil Development with Rails( Edition 2)

I'm trying to run the part where the effect is implemented in
application hightlight depot but is not working, I tried to download the
codes on the site but it also does not work so someone step

Sorry english evil, I am learning:)

Codes

cart.rb
<code>
def add_product(product)
        current_item = @items.find {|item| item.product == product}
        if current_item
            current_item.increment_quantity
        else
          current_item = CartItem.new(product)
          @items << current_item
        end
        current_item
   end
</code>

store_controller
<code>
def add_to_cart
    begin
      product = Product.find(params[:id])
    rescue ActiveRecord::RecordNotFound
      logger.error("Attempt to access invalid product #{params[:id]}")
      redirect_to_index("Invalid product")
    else
      @cart = find_cart
      @current_item = @cart.add_product(product)
    end
  end
</code>

Partial _cart_item.rhtml
<code>
<% if cart_item == @current_item %>
   <tr id="current_item">
<% else %>
<tr>
<% end %>

        <td><%= cart_item.quantity %>&times;</td>
        <td><%= h(cart_item.title) %> </td>
        <td class="item-price"><%= number_to_currency(cart_item.price)
%></td>
</tr>
</code>

add_to_cart.rjs

<code>
page.replace_html("cart", :partial => "cart", :object => @cart)

page[:current_item].visual_effect :highlight,
                                                    :startcolor =>
"#88ff88",
                                                    :endcolor =>
"#114411"

</code>

Thaks

Ajax magic does not work - Book Agil Development with Rails( Edition 2)

I'm trying to run the part where the effect is implemented in
application hightlight depot but is not working, I tried to download the
codes on the site but it also does not work so someone step

In what way does it not work?

Fred