The Depot Application

9.2 Iteration D2: Creating an AJAX-Based Cart

edit app/views/store/index.html.erb

    <%= form_tag({:action=>'add_to_cart', :id=>product}, :remote=>true) do %>

      <%= submit_tag "Add to Cart" %>

    <% end %>

edit app/views/layouts/store.html.erb

<html>

<head>

  <title>Pragprog Books Online Store</title>

  <%= stylesheet_link_tag "depot", :media => "all" %>

  <%= javascript_include_tag :defaults %>

</head>

edit app/controllers/store_controller.rb

  def add_to_cart

    product = Product.find(params[:id])

    @cart = find_cart

    @cart.add_product(product)

    respond_to do |format|

      format.js

end

  rescue ActiveRecord::RecordNotFound

    logger.error("Attempt to access invalid product #{params[:id]}")

    redirect_to_index("Invalid product")

end

edit app/views/store/add_to_cart.js.rjs

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