Various methods of adding the 'active' class to a nav menu item

navbar_helper

module NavbarHelper
  # based on url path
  def nav_menu_link_1(name, url)
    active = request.path.starts_with?(url)
    content_tag :li, class: active ? 'active' : nil do
      link_to name, url
    end
  end
  
  # based on controller
  def nav_menu_link_2(resource, name = nil)
    resource = resource.to_s
    name ||= resource.humanize
    active = (params[:controller] == resource)
    content_tag :li, class: active ? 'active' : nil do
      link_to name, send("#{resource}_path")
    end
  end
end