ETag Support from Edge-Rails

Added ETag support from

   http://dev.rubyonrails.org/changeset/6158

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

@@ -7,6 +7,7 @@ require 'action_controller/url_rewriter'
 require 'action_controller/status_codes'
 require 'drb'
 require 'set'
+require 'md5' 
 
 module ActionController #:nodoc:
   class ActionControllerError < StandardError #:nodoc:
@@ -599,6 +600,12 @@ module ActionController #:nodoc:
       # _Deprecation_ _notice_: This used to have the signatures
       # <tt>render_partial(partial_path = default_template_name, object = nil, local_assigns = {})</tt> and
       # <tt>render_partial_collection(partial_name, collection, partial_spacer_template = nil, local_assigns = {})</tt>.
+      # == Automatic etagging 
+      # 
+      # Rendering will automatically insert the etag header on 200 OK responses. The etag is calculated using MD5 of the 
+      # response body. If a request comes in that has a matching etag, the response will be changed to a 304 Not Modified 
+      # and the response body will be set to an empty string. 
+      # 
       #
       # === Rendering a template
       #
@@ -822,6 +829,16 @@ module ActionController #:nodoc:
         else
           response.body = text
         end
+        if response.headers['Status'] == "200 OK" && response.body.size > 0 
+          response.headers['Etag'] = "\"#{MD5.new(text).to_s}\"" 
+           
+          if request.headers['HTTP_IF_NONE_MATCH'] == response.headers['Etag'] 
+            response.headers['Status'] = "304 Not Modified" 
+            response.body = '' 
+          end 
+        end 
+         
+        response.body 
       end
 
       def render_javascript(javascript, status = nil, append_response = true) #:nodoc:

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

@@ -50,6 +50,10 @@ module ActionController
       @env['REQUEST_METHOD'].downcase.to_sym == :head
     end 
 
+    def headers 
+      @env 
+    end
+
     # Determine whether the body of a HTTP call is URL-encoded (default)
     # or matches one of the registered param_parsers. 
     #

vendor/rails/actionpack/test/controller/render_test.rb

@@ -69,6 +69,10 @@ class TestController < ActionController::Base
     render "test/hello"
   end
 
+  def heading
+    head :ok
+  end
+
   def greeting
     # let's just rely on the template
   end
@@ -286,8 +290,50 @@ class RenderTest < Test::Unit::TestCase
     assert_equal "Goodbye, Local David", @response.body
   end
 
+  def test_render_200_should_set_etag
+    get :render_hello_world_from_variable
+    assert_equal etag_for("hello david"), @response.headers['Etag']
+  end
+
+  def test_render_against_etag_request_should_304_when_match
+    @request.headers["HTTP_IF_NONE_MATCH"] = etag_for("hello david")
+    get :render_hello_world_from_variable
+    assert_equal "304 Not Modified", @response.headers['Status']
+    assert @response.body.empty?
+  end
+
+  def test_render_against_etag_request_should_200_when_no_match
+    @request.headers["HTTP_IF_NONE_MATCH"] = etag_for("hello somewhere else")
+    get :render_hello_world_from_variable
+    assert_equal "200 OK", @response.headers['Status']
+    assert !@response.body.empty?
+  end
+
+  def test_render_with_etag
+    get :render_hello_world_from_variable
+    expected_etag = "\"#{MD5.new("hello david").to_s}\""
+    assert_equal expected_etag, @response.headers['Etag']
+    
+    @request.headers["HTTP_IF_NONE_MATCH"] = expected_etag
+    get :render_hello_world_from_variable
+    assert_equal "304 Not Modified", @response.headers['Status']
+    
+    @request.headers["HTTP_IF_NONE_MATCH"] = "\"diftag\""
+    get :render_hello_world_from_variable
+    assert_equal "200 OK", @response.headers['Status']
+  end
+
+  def render_with_404_shouldnt_have_etag
+    get :render_custom_code
+    assert_nil @response.headers['Etag']
+  end
+
   protected
     def assert_deprecated_render(&block)
       assert_deprecated(/render/, &block)
     end
+    
+    def etag_for(text)
+      "\"#{MD5.new(text).to_s}\""
+    end
 end