rocodev-tech

  resources :products do 
    member do 
      post :add_to_cart
    end
  end

rocodev-tech

     <div> 數量 : <%= render_product_quantity(@product) %> </div>
     <div class="product-price"> $ <%= render_product_price(@product) %> </div>

     <div class="pull-right">
      <%= link_to("加入購物車", add_to_cart_product_path(@product) , :method => :post , :class => "btn btn-primary btn-lg btn-danger") %>
     </div>
     

rocodev-tech

  <ul class="nav navbar-nav navbar-right">
 
        <li> 
          <%= link_to "#" do  %>
            購物車 <i class="glyphicon glyphicon-shopping-cart"> </i> (0)
          <% end %>
        </li>
 
        <% if !current_user %>
        <li> <%= link_to("登入", new_user_session_path) %> </li>