tap/app/views/orders/new.html.erb

<%= @user.name %>

<%= form_for( @order, url: user_orders_path(@user)) do |f| %>
  <%= render 'application/errors', model: @order %>

  <div id="form_products">
  <%= f.fields_for :order_products do |op_field| %>
      <%= render 'order_products/form_row', f: op_field %>
  <% end %>
  </div>
  <%= render 'order_products/total_price', f: f %>
  <%= f.submit "Order", class: "btn btn-primary " %>
<% end %>