active_navigation_item.rb

# Usage:
#
# In your controller
#
#   before_filter :set_active_navigation_item
#   def set_active_navigation_item
#     active_navigation_item :we, :are, :here
#     # or
#     active_navigation_item controller.controller_name, controller.action_name
#     # or
#     # any custom logic
#   end
#
# or in your view
#
#   !!!haml
#   - active_navigation_item :we, :are, :here
#
# and then
#
#   !!!haml
#   %nav.second
#   %ul
#     %li
#       =link_to 'we', we_path, class: ('active' if active_navigation_item?(:we)) # true
#       %ul
#         =link_to 'are', are_path, class: ('active' if active_navigation_item_class(:we, :are)) # false
#     %li= link_to 'there', there_path, class: ('active' if active_navigation_item?(:there)) # nil
#
# Caveats:
# Streaming responses might break this because you are likely calling `active_navigation_item` from your view and `active_navigation_item?` from your layout - this means you have to move setting your active navigation item to the controller
module ActiveNavigationItem
  extend ActiveSupport::Concern

  # Set if called with arguments
  # otherwise get array
  def active_navigation_item(*hierarchy)
    if hierarchy.any?
      @active_navigation_item = hierarchy.map(&:to_sym)
    else
      @active_navigation_item
    end
  end

  # Get active navigation item state
  def active_navigation_item?(*hierarchy)
    @active_navigation_item[0...hierarchy.length] == hierarchy.map(&:to_sym) if @active_navigation_item
  end

  included do
    helper_method :active_navigation_item, :active_navigation_item?
  end
end