Unfolding menus on DjangoCMS?

If I have nested pages, is it possible for, for example, the top level menu items only to show, but when I view a page, for its subpages to appear in the navigation?

So for this structure:

• Page 1
• Page 2
  • Page 2a
  • Page 2b
• Page 3

When I visit page 1 I see:

• 开发者_StackOverflow社区Page 1
• Page 2
• Page 3
  • Page 3a
  • Page 3b

When I visit page 2 I see:

• Page 1
• Page 2
  • Page 2a
  • Page 2b
• Page 3

When I visit page 3 I see:

• Page 1
• Page 2
• Page 3
  • Page 3a
  • Page 3b

Yes it is possible and easy. Documentation on the show_menu template-tag explains how to do it.

You need to set extra_active argument to 1, like this:

{% show_menu 0 100 0 1 %}

Here are the names of each argument:

{% show_menu start_level end_level extra_inactive extra_active %}