module NavigationHelpers def path_to(page_name) case page_name when 'the schedules page' '/' when 'the channel overview page' '/channels' when 'the status page' '/status' when 'the shows page' '/shows' else raise "Can't find mapping from \"#{page_name}\" to a path.\n" + "Now, go and add a mapping in #{__FILE__}" end end end World(NavigationHelpers)