Update cache_control to be a Hash of options that is used to build the header.

* Significantly simplifies setting and modifying cache control in other areas

actionpack/lib/action_controller/base/conditional_get.rb

@@ -29,11 +29,7 @@ module ActionController
       response.last_modified = options[:last_modified] if options[:last_modified]
 
       if options[:public]
-        cache_control = response.headers["Cache-Control"].split(",").map {|k| k.strip }
-        cache_control.delete("private")
-        cache_control.delete("no-cache")
-        cache_control << "public"
-        response.headers["Cache-Control"] = cache_control.join(', ')
+        response.cache_control[:public] = true
       end
 
       if request.fresh?(response)
@@ -107,21 +103,10 @@ module ActionController
     # This method will overwrite an existing Cache-Control header.
     # See http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html for more possibilities.
     def expires_in(seconds, options = {}) #:doc:
-      cache_control = response.headers["Cache-Control"].split(",").map {|k| k.strip }
+      response.cache_control.merge!(:max_age => seconds, :public => options.delete(:public))
+      options.delete(:private)
 
-      cache_control << "max-age=#{seconds}"
-      cache_control.delete("no-cache")
-      if options[:public]
-        cache_control.delete("private")
-        cache_control << "public"
-      else
-        cache_control << "private"
-      end
-
-      # This allows for additional headers to be passed through like 'max-stale' => 5.hours
-      cache_control += options.symbolize_keys.reject{|k,v| k == :public || k == :private }.map{ |k,v| v == true ? k.to_s : "#{k.to_s}=#{v.to_s}"}
-
-      response.headers["Cache-Control"] = cache_control.join(', ')
+      response.cache_control[:extras] = options.map {|k,v| "#{k}=#{v}"}
     end
 
     # Sets a HTTP 1.1 Cache-Control header of "no-cache" so no caching should occur by the browser or

actionpack/lib/action_controller/base/streaming.rb

@@ -181,7 +181,7 @@ module ActionController #:nodoc:
         # after it displays the "open/save" dialog, which means that if you
         # hit "open" the file isn't there anymore when the application that
         # is called for handling the download is run, so let's workaround that
-        headers['Cache-Control'] = 'private' if headers['Cache-Control'] == 'no-cache'
+        response.cache_control[:public] ||= false
       end
   end
 end

actionpack/lib/action_controller/testing/process.rb

@@ -52,7 +52,7 @@ module ActionController #:nodoc:
   class TestResponse < ActionDispatch::TestResponse
     def recycle!
       @status = 200
-      @header = Rack::Utils::HeaderHash.new(DEFAULT_HEADERS)
+      @header = Rack::Utils::HeaderHash.new
       @writer = lambda { |x| @body << x }
       @block = nil
       @length = 0

actionpack/lib/action_dispatch/http/response.rb

@@ -32,8 +32,8 @@ module ActionDispatch # :nodoc:
   #    end
   #  end
   class Response < Rack::Response
-    DEFAULT_HEADERS = { "Cache-Control" => "no-cache" }
     attr_accessor :request
+    attr_reader :cache_control
 
     attr_writer :header
     alias_method :headers=, :header=
@@ -42,7 +42,8 @@ module ActionDispatch # :nodoc:
 
     def initialize
       super
-      @header = Rack::Utils::HeaderHash.new(DEFAULT_HEADERS)
+      @cache_control = {}
+      @header = Rack::Utils::HeaderHash.new
     end
 
     # The response code of the request
@@ -196,7 +197,7 @@ module ActionDispatch # :nodoc:
 
     private
       def handle_conditional_get!
-        if etag? || last_modified?
+        if etag? || last_modified? || !cache_control.empty?
           set_conditional_cache_control!
         elsif nonempty_ok_response?
           self.etag = body
@@ -207,6 +208,8 @@ module ActionDispatch # :nodoc:
           end
 
           set_conditional_cache_control!
+        else
+          headers["Cache-Control"] = "no-cache"
         end
       end
 
@@ -220,9 +223,20 @@ module ActionDispatch # :nodoc:
       end
 
       def set_conditional_cache_control!
-        if headers['Cache-Control'] == DEFAULT_HEADERS['Cache-Control']
-          headers['Cache-Control'] = 'private, max-age=0, must-revalidate'
+        if cache_control.empty?
+          cache_control.merge!(:public => false, :max_age => 0, :must_revalidate => true)
         end
+
+        public_cache, max_age, must_revalidate, extras =
+          cache_control.values_at(:public, :max_age, :must_revalidate, :extras)
+
+        options = []
+        options << "max-age=#{max_age}" if max_age
+        options << (public_cache ? "public" : "private")
+        options << "must-revalidate" if must_revalidate
+        options.concat(extras) if extras
+
+        headers["Cache-Control"] = options.join(", ")
       end
 
       def convert_content_type!

actionpack/test/controller/render_test.rb

@@ -1331,7 +1331,7 @@ class EtagRenderTest < ActionController::TestCase
   def test_render_200_should_set_etag
     get :render_hello_world_from_variable
     assert_equal etag_for("hello david"), @response.headers['ETag']
-    assert_equal "private, max-age=0, must-revalidate", @response.headers['Cache-Control']
+    assert_equal "max-age=0, private, must-revalidate", @response.headers['Cache-Control']
   end
 
   def test_render_against_etag_request_should_304_when_match

actionpack/test/controller/send_file_test.rb

@@ -129,7 +129,7 @@ class SendFileTest < ActionController::TestCase
     # test overriding Cache-Control: no-cache header to fix IE open/save dialog
     @controller.headers = { 'Cache-Control' => 'no-cache' }
     @controller.send(:send_file_headers!, options)
-    h = @controller.headers
+    @controller.response.prepare!
     assert_equal 'private', h['Cache-Control']
   end
 

actionpack/test/dispatch/response_test.rb

@@ -13,7 +13,7 @@ class ResponseTest < ActiveSupport::TestCase
     assert_equal 200, status
     assert_equal({
       "Content-Type" => "text/html; charset=utf-8",
-      "Cache-Control" => "private, max-age=0, must-revalidate",
+      "Cache-Control" => "max-age=0, private, must-revalidate",
       "ETag" => '"65a8e27d8879283831b664bd8b7f0ad4"',
       "Set-Cookie" => "",
       "Content-Length" => "13"
@@ -32,7 +32,7 @@ class ResponseTest < ActiveSupport::TestCase
     assert_equal 200, status
     assert_equal({
       "Content-Type" => "text/html; charset=utf-8",
-      "Cache-Control" => "private, max-age=0, must-revalidate",
+      "Cache-Control" => "max-age=0, private, must-revalidate",
       "ETag" => '"ebb5e89e8a94e9dd22abf5d915d112b2"',
       "Set-Cookie" => "",
       "Content-Length" => "8"