module Rack # Rack::Cascade tries an request on several apps, and returns the # first response that is not 404 (or in a list of configurable # status codes). class Cascade NotFound = [404, {"Content-Type" => "text/plain"}, []] attr_reader :apps def initialize(apps, catch=[404, 405]) @apps = []; @has_app = {} apps.each { |app| add app } @catch = {} [*catch].each { |status| @catch[status] = true } end def call(env) result = NotFound @apps.each do |app| result = app.call(env) break unless @catch.include?(result[0].to_i) end result end def add app @has_app[app] = true @apps << app end def include? app @has_app.include? app end alias_method :<<, :add end end