<% if content_for?(:main) %>
<%= yield :main %>
<% end %>
<% if content_for?(:manage) || content_for?(:filter) %>
<% if content_for?(:manage) %>
Управление
<%= yield :manage %>
<% end %>
<% if content_for?(:filter) %>
Фильтр
<%= yield :filter %>
<% end %>
<% end %>
<%= yield %>