Added media_type methods in Rack::Response

lib/rack/media_type.rb

@@ -0,0 +1,38 @@
+module Rack
+  # Rack::MediaType parse media type and parameters out of content_type string
+
+  class MediaType
+    SPLIT_PATTERN = %r{\s*[;,]\s*}
+
+    class << self
+      # The media type (type/subtype) portion of the CONTENT_TYPE header
+      # without any media type parameters. e.g., when CONTENT_TYPE is
+      # "text/plain;charset=utf-8", the media-type is "text/plain".
+      #
+      # For more information on the use of media types in HTTP, see:
+      # http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.7
+      def type(content_type)
+        return nil unless content_type
+        content_type.split(SPLIT_PATTERN, 2).first.downcase
+      end
+
+      # The media type parameters provided in CONTENT_TYPE as a Hash, or
+      # an empty Hash if no CONTENT_TYPE or media-type parameters were
+      # provided.  e.g., when the CONTENT_TYPE is "text/plain;charset=utf-8",
+      # this method responds with the following Hash:
+      #   { 'charset' => 'utf-8' }
+      def params(content_type)
+        return {} if content_type.nil?
+        Hash[*content_type.split(SPLIT_PATTERN)[1..-1].
+          collect { |s| s.split('=', 2) }.
+          map { |k,v| [k.downcase, strip_doublequotes(v)] }.flatten]
+      end
+
+      private
+
+        def strip_doublequotes(str)
+          (str[0] == ?" && str[-1] == ?") ? str[1..-2] : str
+        end
+    end
+  end
+end

lib/rack/request.rb

@@ -1,4 +1,5 @@
 require 'rack/utils'
+require 'rack/media_type'
 
 module Rack
   # Rack::Request provides a convenient interface to a Rack
@@ -46,7 +47,7 @@ def logger;          @env['rack.logger']                      end
     # For more information on the use of media types in HTTP, see:
     # http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.7
     def media_type
-      content_type && content_type.split(/\s*[;,]\s*/, 2).first.downcase
+      @media_type ||= MediaType.type(content_type)
     end
 
     # The media type parameters provided in CONTENT_TYPE as a Hash, or
@@ -55,10 +56,7 @@ def media_type
     # this method responds with the following Hash:
     #   { 'charset' => 'utf-8' }
     def media_type_params
-      return {} if content_type.nil?
-      Hash[*content_type.split(/\s*[;,]\s*/)[1..-1].
-        collect { |s| s.split('=', 2) }.
-        map { |k,v| [k.downcase, strip_doublequotes(v)] }.flatten]
+      @media_type_params ||= MediaType.params(content_type)
     end
 
     # The character set of the request body if a "charset" media type
@@ -384,14 +382,5 @@ def parse_http_accept_header(header)
           [attribute, quality]
         end
       end
-
-  private
-    def strip_doublequotes(s)
-      if s[0] == ?" && s[-1] == ?"
-        s[1..-2]
-      else
-        s
-      end
-    end
   end
 end

lib/rack/response.rb

@@ -1,6 +1,7 @@
 require 'rack/request'
 require 'rack/utils'
 require 'rack/body_proxy'
+require 'rack/media_type'
 require 'time'
 
 module Rack
@@ -150,6 +151,14 @@ def content_type
         headers[CONTENT_TYPE]
       end
 
+      def media_type
+        @media_type ||= MediaType.type(content_type)
+      end
+
+      def media_type_params
+        @media_type_params ||= MediaType.params(content_type)
+      end
+
       def content_length
         cl = headers[CONTENT_LENGTH]
         cl ? cl.to_i : cl

test/spec_media_type.rb

@@ -0,0 +1,41 @@
+require 'rack/media_type'
+
+describe Rack::MediaType do
+  before { @empty_hash = {} }
+
+  describe 'when content_type nil' do
+    before { @content_type = nil }
+
+    it '#type is nil' do
+      Rack::MediaType.type(@content_type).should.be.nil
+    end
+
+    it '#params is empty' do
+      Rack::MediaType.params(@content_type).should.equal @empty_hash
+    end
+  end
+
+  describe 'when content_type contains only media_type' do
+    before { @content_type = 'application/text' }
+
+    it '#type is application/text' do
+      Rack::MediaType.type(@content_type).should.equal 'application/text'
+    end
+
+    it  '#params is empty' do
+      Rack::MediaType.params(@content_type).should.equal @empty_hash
+    end
+  end
+
+  describe 'when content_type contains media_type and params' do
+    before { @content_type = 'application/text;CHARSET="utf-8"' }
+
+    it '#type is application/text' do
+      Rack::MediaType.type(@content_type).should.equal 'application/text'
+    end
+
+    it '#params has key "charset" with value "utf-8"' do
+      Rack::MediaType.params(@content_type)['charset'].should.equal 'utf-8'
+    end
+  end
+end