simple active menu rails

application_helper.rb

def current_class?(test_path)
  request.path == test_path ? 'active' : ''
end

nav.html

<ul class="menu-list">
  <li><%= link_to t('home'), root_path, :class => active_class(root_path) %></li>
  <li><%= link_to t('products'), products_path, :class => active_class(products_path) %></li>
  <li><%= link_to t('news'), news_index_path, :class => active_class(news_index_path) %></li>
  <li><%= link_to t('contact'), contacts_path, :class => active_class(contacts_path) %></li>
  <li><%= link_to t('about_us'), about_path, :class => active_class(about_path) %></li>
</ul>