middleware_dummycode.rb

require 'rubygems'
require 'rack'

class Rack
  class PlayCo
    class RequestValidator
      
      # ==== Parameters
      # app<Rack::Builder>:: The Rack builder which will use this middleware.
      # path_opts<Hash>:: Path options used to identify path to validate.
      #
      # ==== Options (path_opts)
      # :http_methods<Array, String>::
      #   'POST', 'GET', 'DELETE' or 'UPDATE' HTTP verb used against 
      #   env['REQUEST_METHOD'].
      # :path<Regexp, string>:: Regular expression or stirng filtering requests
      #   to validate based on the request path. Used against env["REQUEST_PATH"]
      #
      # ==== Examples
      #
      #  (Rails 2.x) in RAILS_ROOT/config.ru:
      #   use Rack::PlayCo::RequestValidator :http_method => ['POST', 'GET'], 
      #                                      :path => /API\/v\d+\//
      def initialize(app, path_opts)
       @app = app
       # TODO validate the path_opts and/or set defaults
       @path_opts = path_opts
      end

     def call(env)
       if validated_request_method?(env) && validated_path?(env)
         post_body = env['rack.input'] ? env['rack.input'].read : nil
         if valid_post_body?(post_body)
           @app.call(env)
         else
           [400, {"Content-Type" => "text/html"}, [post_body]]
         end
       end
     end
     
     def validated_request_method?(env)
       @path_ops[:http_methods].include?(env['REQUEST_METHOD'])
     end
     
     def validated_path?(env)
       if @path_ops[:path].is_a? Regexp
         !(env["REQUEST_PATH"] =~ @path_ops[:path].is_a?).nil?
       else
          env["REQUEST_PATH"] == @path_ops[:path]
       end
     end

     def valid_post_body?(body)
       false
     end
   end
 end
end