_list.html.erb

<% @orders.each do |order| %>
  <% if order.authorized %>
    <tr class="order_authorized">
  <% else %>
    <tr>
  <% end %>
    <td><%= link_to order.user.email, user_path(order.user) %></td>
    <td><%= link_to order.id, order_path(order) %></td>
    <td><%= order.created_at.strftime("%d %B %Y") %></td>
    <td><%= number_to_currency(order.line_items.sum(:price), :unit => "€") %></td>
    <td><%= link_to 'Show', order %></td>
    <td><%= link_to 'Edit', edit_order_path(order) %></td>
    <td><%= link_to 'Destroy', order, method: :delete, data: { confirm: 'Are you sure?' } %></td>
  </tr>
<% end %>