Multi level menu, active links css highlight. (Ruby on Rails)

Question

Site structure:

/
/products
/products/design
/products/photo
/about

I want to see parent menu item also highlighted by CSS, when child is active.

(When 'design' or 'photo' is active 'products' should be highlighted too.)

I'm using this for child and simple urls:

<li class="<%= current_page?(:action => 'design') %>">
    <%= link_to_unless_current 'Design', :design %>
</li>

For 'products' checking should be like:

<%= current_page?(:action => 'products') ||
current_page?(:action => 'design') %> ||
current_page?(:action => 'photo') %>

But triple || is not right, and it's become complicated.

I saw a helper, like this one:

def current(childs)
  if current_page?(:action => childs) 
  @container = "active"
  else
  @container = "inactive"
  end
end

Which is used by: <%= current(:photo) %>

So, how to put all my 3 checks for 'products', 'design', 'photo' in one helper?

And make possible to use something like <%= current(:products, :design, :photo) %>

Answer 1

I wouldn't recreate the wheel and use a Rails menu-builder gem/plugin like simple-navigation.

Here's a demo of navigation and styling.