vendor/rails/actionpack/lib/action_controller/response.rb

   1 require 'digest/md5'
   2
   3 module ActionController # :nodoc:
   4   # Represents an HTTP response generated by a controller action. One can use
   5   # an ActionController::Response object to retrieve the current state
   6   # of the response, or customize the response. An Response object can
   7   # either represent a "real" HTTP response (i.e. one that is meant to be sent
   8   # back to the web browser) or a test response (i.e. one that is generated
   9   # from integration tests). See CgiResponse and TestResponse, respectively.
  10   #
  11   # Response is mostly a Ruby on Rails framework implement detail, and
  12   # should never be used directly in controllers. Controllers should use the
  13   # methods defined in ActionController::Base instead. For example, if you want
  14   # to set the HTTP response's content MIME type, then use
  15   # ActionControllerBase#headers instead of Response#headers.
  16   #
  17   # Nevertheless, integration tests may want to inspect controller responses in
  18   # more detail, and that's when Response can be useful for application
  19   # developers. Integration test methods such as
  20   # ActionController::Integration::Session#get and
  21   # ActionController::Integration::Session#post return objects of type
  22   # TestResponse (which are of course also of type Response).
  23   #
  24   # For example, the following demo integration "test" prints the body of the
  25   # controller response to the console:
  26   #
  27   #  class DemoControllerTest < ActionController::IntegrationTest
  28   #    def test_print_root_path_to_console
  29   #      get('/')
  30   #      puts @response.body
  31   #    end
  32   #  end
  33   class Response < Rack::Response
  34     DEFAULT_HEADERS = { "Cache-Control" => "no-cache" }
  35     attr_accessor :request
  36
  37     attr_accessor :session, :assigns, :template, :layout
  38     attr_accessor :redirected_to, :redirected_to_method_params
  39
  40     delegate :default_charset, :to => 'ActionController::Base'
  41
  42     def initialize
  43       @status = 200
  44       @header = Rack::Utils::HeaderHash.new(DEFAULT_HEADERS)
  45
  46       @writer = lambda { |x| @body << x }
  47       @block = nil
  48
  49       @body = "",
  50       @session, @assigns = [], []
  51     end
  52
  53     def location; headers['Location'] end
  54     def location=(url) headers['Location'] = url end
  55
  56
  57     # Sets the HTTP response's content MIME type. For example, in the controller
  58     # you could write this:
  59     #
  60     #  response.content_type = "text/plain"
  61     #
  62     # If a character set has been defined for this response (see charset=) then
  63     # the character set information will also be included in the content type
  64     # information.
  65     def content_type=(mime_type)
  66       self.headers["Content-Type"] =
  67         if mime_type =~ /charset/ || (c = charset).nil?
  68           mime_type.to_s
  69         else
  70           "#{mime_type}; charset=#{c}"
  71         end
  72     end
  73
  74     # Returns the response's content MIME type, or nil if content type has been set.
  75     def content_type
  76       content_type = String(headers["Content-Type"] || headers["type"]).split(";")[0]
  77       content_type.blank? ? nil : content_type
  78     end
  79
  80     # Set the charset of the Content-Type header. Set to nil to remove it.
  81     # If no content type is set, it defaults to HTML.
  82     def charset=(charset)
  83       headers["Content-Type"] =
  84         if charset
  85           "#{content_type || Mime::HTML}; charset=#{charset}"
  86         else
  87           content_type || Mime::HTML.to_s
  88         end
  89     end
  90
  91     def charset
  92       charset = String(headers["Content-Type"] || headers["type"]).split(";")[1]
  93       charset.blank? ? nil : charset.strip.split("=")[1]
  94     end
  95
  96     def last_modified
  97       if last = headers['Last-Modified']
  98         Time.httpdate(last)
  99       end
 100     end
 101
 102     def last_modified?
 103       headers.include?('Last-Modified')
 104     end
 105
 106     def last_modified=(utc_time)
 107       headers['Last-Modified'] = utc_time.httpdate
 108     end
 109
 110     def etag
 111       headers['ETag']
 112     end
 113
 114     def etag?
 115       headers.include?('ETag')
 116     end
 117
 118     def etag=(etag)
 119       if etag.blank?
 120         headers.delete('ETag')
 121       else
 122         headers['ETag'] = %("#{Digest::MD5.hexdigest(ActiveSupport::Cache.expand_cache_key(etag))}")
 123       end
 124     end
 125
 126     def redirect(url, status)
 127       self.status = status
 128       self.location = url.gsub(/[\r\n]/, '')
 129       self.body = "<html><body>You are being <a href=\"#{CGI.escapeHTML(url)}\">redirected</a>.</body></html>"
 130     end
 131
 132     def sending_file?
 133       headers["Content-Transfer-Encoding"] == "binary"
 134     end
 135
 136     def assign_default_content_type_and_charset!
 137       self.content_type ||= Mime::HTML
 138       self.charset ||= default_charset unless sending_file?
 139     end
 140
 141     def prepare!
 142       assign_default_content_type_and_charset!
 143       handle_conditional_get!
 144       set_content_length!
 145       convert_content_type!
 146       convert_language!
 147       convert_cookies!
 148     end
 149
 150     def each(&callback)
 151       if @body.respond_to?(:call)
 152         @writer = lambda { |x| callback.call(x) }
 153         @body.call(self, self)
 154       elsif @body.is_a?(String)
 155         @body.each_line(&callback)
 156       else
 157         @body.each(&callback)
 158       end
 159
 160       @writer = callback
 161       @block.call(self) if @block
 162     end
 163
 164     def write(str)
 165       @writer.call str.to_s
 166       str
 167     end
 168
 169     def set_cookie(key, value)
 170       if value.has_key?(:http_only)
 171         ActiveSupport::Deprecation.warn(
 172           "The :http_only option in ActionController::Response#set_cookie " +
 173           "has been renamed. Please use :httponly instead.", caller)
 174         value[:httponly] ||= value.delete(:http_only)
 175       end
 176
 177       super(key, value)
 178     end
 179
 180     private
 181       def handle_conditional_get!
 182         if etag? || last_modified?
 183           set_conditional_cache_control!
 184         elsif nonempty_ok_response?
 185           self.etag = body
 186
 187           if request && request.etag_matches?(etag)
 188             self.status = '304 Not Modified'
 189             self.body = ''
 190           end
 191
 192           set_conditional_cache_control!
 193         end
 194       end
 195
 196       def nonempty_ok_response?
 197         ok = !status || status.to_s[0..2] == '200'
 198         ok && body.is_a?(String) && !body.empty?
 199       end
 200
 201       def set_conditional_cache_control!
 202         if headers['Cache-Control'] == DEFAULT_HEADERS['Cache-Control']
 203           headers['Cache-Control'] = 'private, max-age=0, must-revalidate'
 204         end
 205       end
 206
 207       def convert_content_type!
 208         headers['Content-Type'] ||= "text/html"
 209         headers['Content-Type'] += "; charset=" + headers.delete('charset') if headers['charset']
 210       end
 211
 212       # Don't set the Content-Length for block-based bodies as that would mean
 213       # reading it all into memory. Not nice for, say, a 2GB streaming file.
 214       def set_content_length!
 215         if status && status.to_s[0..2] == '204'
 216           headers.delete('Content-Length')
 217         elsif length = headers['Content-Length']
 218           headers['Content-Length'] = length.to_s
 219         elsif !body.respond_to?(:call) && (!status || status.to_s[0..2] != '304')
 220           headers["Content-Length"] = (body.respond_to?(:bytesize) ? body.bytesize : body.size).to_s
 221         end
 222       end
 223
 224       def convert_language!
 225         headers["Content-Language"] = headers.delete("language") if headers["language"]
 226       end
 227
 228       def convert_cookies!
 229         headers['Set-Cookie'] = Array(headers['Set-Cookie']).compact
 230       end
 231   end
 232 end