module ActiveAdmin::BaseController::Menu

def current_menu
  active_admin_config.navigation_menu
end

def current_menu_item?(item)
  item.current?(@current_menu_item)
end

def set_current_menu_item
  @current_menu_item = if current_menu && active_admin_config.belongs_to? && parent?
                         parent_item = active_admin_config.belongs_to_config.target.menu_item
                         if current_menu.include? parent_item
                           parent_item
                         else
                           active_admin_config.menu_item
                         end
                       else
                         active_admin_config.menu_item
                       end
end