lib/rack/recursive.rb

   1 # frozen_string_literal: true
   2
   3 require 'uri'
   4
   5 require_relative 'constants'
   6
   7 module Rack
   8   # Rack::ForwardRequest gets caught by Rack::Recursive and redirects
   9   # the current request to the app at +url+.
  10   #
  11   #   raise ForwardRequest.new("/not-found")
  12   #
  13
  14   class ForwardRequest < Exception
  15     attr_reader :url, :env
  16
  17     def initialize(url, env = {})
  18       @url = URI(url)
  19       @env = env
  20
  21       @env[PATH_INFO]       = @url.path
  22       @env[QUERY_STRING]    = @url.query  if @url.query
  23       @env[HTTP_HOST]       = @url.host   if @url.host
  24       @env[HTTP_PORT]       = @url.port   if @url.port
  25       @env[RACK_URL_SCHEME] = @url.scheme if @url.scheme
  26
  27       super "forwarding to #{url}"
  28     end
  29   end
  30
  31   # Rack::Recursive allows applications called down the chain to
  32   # include data from other applications (by using
  33   # <tt>rack['rack.recursive.include'][...]</tt> or raise a
  34   # ForwardRequest to redirect internally.
  35
  36   class Recursive
  37     def initialize(app)
  38       @app = app
  39     end
  40
  41     def call(env)
  42       dup._call(env)
  43     end
  44
  45     def _call(env)
  46       @script_name = env[SCRIPT_NAME]
  47       @app.call(env.merge(RACK_RECURSIVE_INCLUDE => method(:include)))
  48     rescue ForwardRequest => req
  49       call(env.merge(req.env))
  50     end
  51
  52     def include(env, path)
  53       unless path.index(@script_name) == 0 && (path[@script_name.size] == ?/ ||
  54                                                path[@script_name.size].nil?)
  55         raise ArgumentError, "can only include below #{@script_name}, not #{path}"
  56       end
  57
  58       env = env.merge(PATH_INFO => path,
  59                       SCRIPT_NAME => @script_name,
  60                       REQUEST_METHOD => GET,
  61                       "CONTENT_LENGTH" => "0", "CONTENT_TYPE" => "",
  62                       RACK_INPUT => StringIO.new(""))
  63       @app.call(env)
  64     end
  65   end
  66 end