Ported fresh_when into a ConditionalGet module

1 files changed, 42 insertions, 0 deletions

diff --git a/actionpack/lib/action_controller/new_base/conditional_get.rb b/actionpack/lib/action_controller/new_base/conditional_get.rb
new file mode 100644
index 0000000000..16104c51fc
--- /dev/null
+++ b/actionpack/lib/action_controller/new_base/conditional_get.rb
@@ -0,0 +1,42 @@
+module ActionController
+  module ConditionalGet
+    
+    # Sets the etag, last_modified, or both on the response and renders a
+    # "304 Not Modified" response if the request is already fresh.
+    #
+    # Parameters:
+    # * <tt>:etag</tt>
+    # * <tt>:last_modified</tt> 
+    # * <tt>:public</tt> By default the Cache-Control header is private, set this to true if you want your application to be cachable by other devices (proxy caches).
+    #
+    # Example:
+    #
+    #   def show
+    #     @article = Article.find(params[:id])
+    #     fresh_when(:etag => @article, :last_modified => @article.created_at.utc, :public => true)
+    #   end
+    #
+    # This will render the show template if the request isn't sending a matching etag or
+    # If-Modified-Since header and just a "304 Not Modified" response if there's a match.
+    #    
+    def fresh_when(options)
+      options.assert_valid_keys(:etag, :last_modified, :public)
+
+      response.etag          = options[:etag]          if options[:etag]
+      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(', ')
+      end
+
+      if request.fresh?(response)
+        head :not_modified
+      end
+    end    
+    
+  end
+end
\ No newline at end of file