vendor/rails/actionpack/lib/action_controller/vendor/rack-1.0/rack/cascade.rb

   1 module Rack
   2   # Rack::Cascade tries an request on several apps, and returns the
   3   # first response that is not 404 (or in a list of configurable
   4   # status codes).
   5
   6   class Cascade
   7     attr_reader :apps
   8
   9     def initialize(apps, catch=404)
  10       @apps = apps
  11       @catch = [*catch]
  12     end
  13
  14     def call(env)
  15       status = headers = body = nil
  16       raise ArgumentError, "empty cascade"  if @apps.empty?
  17       @apps.each { |app|
  18         begin
  19           status, headers, body = app.call(env)
  20           break  unless @catch.include?(status.to_i)
  21         end
  22       }
  23       [status, headers, body]
  24     end
  25
  26     def add app
  27       @apps << app
  28     end
  29
  30     def include? app
  31       @apps.include? app
  32     end
  33
  34     alias_method :<<, :add
  35   end
  36 end