I'm getting an error and unable to figure it out...

around pages 108-110 (pdf), I have written the code for the shopping cart, but when I push the ‘add to cart’ button I get a ‘NoMethodError in StoreController#add_to_cart’ and that I have a nil object when I didn’t expect it…

I have the method in the StoreController and everything is exactly what is written in the book…

would anybody care to help me out?

Without seeing your code, I’d say to check and make sure that your add_to_cart definition in app/controllers/store_controller.rb is in the public section. In other words, make sure your definition isn’t below the “private” keyword (assuming you’ve added it to hide the find_cart definition).

If that doesn’t help, it would make it easier to see what’s going on if I (or someone who actually knows what they’re doing) could see your code for these files:

app/models/cart.rb
app/controllers/store_controller.rb
app/views/store/index.rhtml

I’m having the same problem

Any help would be greatly appreciated.

cart.rb —-

class Cart
  attr_reader :items

  def initialize
    @items = []
  end

  def add_product(product)
    @items << product
  end
end

store_controller.rb ——

class StoreController < ApplicationController

  def index
    @products = Product.find_products_for_sale
  end

  def add_to_cart
    @cart = find_cart
    product = Product.find(params[:id])
    @card.add_product(product)
  end

  private

  def find_cart
    session[:cart] ||= Cart.new
  end

end

index.rhtml —-

<h1>Your Pragmatic Catalog</h1>

<% for product in @products -%>
  <div class = "entry">
    <img src = "<%= product.image_url %>"/>
    <h3><%= h(product.title) %></h3>
    <%= product.description %>
    <span class = "price">
      <%= number_to_currency(product.price) %>
    </span>
    <%= button_to "Add to Cart",
                  :action => :add_to_cart,
                  :id => product %>
  </div>
<% end %>

Hi Theodore,

In your store_controller.rb you have a typo:

current: @card.add_product(product)
better: @cart.add_product(product)

Thomas