etag! and last_modified! conditional GET helpers

2 files changed, 47 insertions, 8 deletions

diff --git a/actionpack/lib/action_controller/base.rb b/actionpack/lib/action_controller/base.rb
index c56812c2d9..50727c67c4 100755
--- a/actionpack/lib/action_controller/base.rb
+++ b/actionpack/lib/action_controller/base.rb
@@ -519,6 +519,8 @@ module ActionController #:nodoc:
     public
       # Extracts the action_name from the request parameters and performs that action.
       def process(request, response, method = :perform_action, *arguments) #:nodoc:
+        response.request = request
+
         initialize_template_class(response)
         assign_shortcuts(request, response)
         initialize_current_url
@@ -529,8 +531,6 @@ module ActionController #:nodoc:
         send(method, *arguments)
 
         assign_default_content_type_and_charset
-
-        response.request = request
         response.prepare! unless component_request?
         response
       ensure
@@ -968,6 +968,17 @@ module ActionController #:nodoc:
         render :nothing => true, :status => status
       end
 
+      # Sets the Last-Modified response header. Returns 304 Not Modified if the
+      # If-Modified-Since request header is <= last modified.
+      def last_modified!(utc_time)
+        head(:not_modified) if response.last_modified!(utc_time)
+      end
+
+      # Sets the ETag response header. Returns 304 Not Modified if the
+      # If-None-Match request header matches.
+      def etag!(etag)
+        head(:not_modified) if response.etag!(etag)
+      end
 
       # Clears the rendered results, allowing for another render to be performed.
       def erase_render_results #:nodoc:
diff --git a/actionpack/lib/action_controller/response.rb b/actionpack/lib/action_controller/response.rb
index 1d9f6676ba..9955532844 100755
--- a/actionpack/lib/action_controller/response.rb
+++ b/actionpack/lib/action_controller/response.rb
@@ -41,20 +41,48 @@ module ActionController
       set_content_length!
     end
 
+    # Sets the Last-Modified response header. Returns whether it's older than
+    # the If-Modified-Since request header.
+    def last_modified!(utc_time)
+      headers['Last-Modified'] ||= utc_time.httpdate
+      if request && since = request.headers['HTTP_IF_MODIFIED_SINCE']
+        utc_time <= Time.rfc2822(since)
+      end
+    end
+
+    # Sets the ETag response header. Returns whether it matches the
+    # If-None-Match request header.
+    def etag!(tag)
+      headers['ETag'] ||= %("#{Digest::MD5.hexdigest(ActiveSupport::Cache.expand_cache_key(tag))}")
+      if request && request.headers['HTTP_IF_NONE_MATCH'] == headers['ETag']
+        true
+      end
+    end
 
     private
       def handle_conditional_get!
-        if body.is_a?(String) && (headers['Status'] ? headers['Status'][0..2] == '200' : true)  && !body.empty?
-          self.headers['ETag'] ||= %("#{Digest::MD5.hexdigest(body)}")
-          self.headers['Cache-Control'] = 'private, max-age=0, must-revalidate' if headers['Cache-Control'] == DEFAULT_HEADERS['Cache-Control']
+        if nonempty_ok_response?
+          set_conditional_cache_control!
 
-          if request.headers['HTTP_IF_NONE_MATCH'] == headers['ETag']
-            self.headers['Status'] = '304 Not Modified'
+          if etag!(body)
+            headers['Status'] = '304 Not Modified'
             self.body = ''
           end
         end
       end
 
+      def nonempty_ok_response?
+        status = headers['Status']
+        ok = !status || status[0..2] == '200'
+        ok && body.is_a?(String) && !body.empty?
+      end
+
+      def set_conditional_cache_control!
+        if headers['Cache-Control'] == DEFAULT_HEADERS['Cache-Control']
+          headers['Cache-Control'] = 'private, max-age=0, must-revalidate'
+        end
+      end
+
       def convert_content_type!
         if content_type = headers.delete("Content-Type")
           self.headers["type"] = content_type
@@ -73,4 +101,4 @@ module ActionController
         self.headers["Content-Length"] = body.size unless body.respond_to?(:call)
       end
   end
-end
\ No newline at end of file
+end