Question

I’m trying to calculate a total price for all the items contained within a cart. However I’m getting a undefined method total_cart_price for ActiveRecord::Relation:xxx

Shop Cart Model (shop_cart.rb)

has_many :shop_cart_items, :dependent => :destroy


  def total_cart_price
    shop_cart_items.to_a.sum { |item| item.total_price }
  end

Shop Cart Item Model (shop_cart_item.rb)

attr_accessible :quantity, :shop_cart_id, :shop_product_id

  belongs_to :shop_product
  belongs_to :shop_cart


  def total_price
    shop_product.sell * quantity
  end

Basket View (shop/basket.html.erb)

<tbody>
    <% @cart_items.each do |item| %>
        <tr>
        <td><%= item.shop_product.name %></td>
        <td><%= number_to_currency(item.shop_product.sell) %></td>
        <td><%= item.quantity %></td>
        <td><%= number_to_currency(item.total_price) %></td>
        </tr>
    <% end %>
    <tr>
    <td></td>
    <td></td>
    <td>Subtotal:</td>
    <td><%= number_to_currency(@cart_items.total_cart_price) %></td>
    </tr>
</tbody>

The total price, for a single item, works fine; the error is trying to calculate a sum of all the items.

I do not have a shop_cart controller or views as I am calling the methods from a shop#basket view – not sure if this is what is causing the problem?

Any help much appreciated.

Answer 1

Try this,
@cart_items.shop_cart.total_cart_price it’s a cart method.