menu_rsc
Return the menu to be displayed with a resource.
Checks the results of the menu_rsc notification. If that returns undefined then
the predicate hasmenu
is used to find menus attached to the resource. The first
in the list is returned by this filter.
If no menu is found then the menu resource id with name main_menu
is returned.
Example:
{% if id|menu_rsc as menu_id %}
.. display the menu with id menu_id ..
{% endif %}