Add support to render :once.

This will be used internally by sprockets to ensure requires are executed just once.

1 files changed, 7 insertions, 0 deletions

diff --git a/actionpack/lib/action_view/render/rendering.rb b/actionpack/lib/action_view/render/rendering.rb
index adbb6bc626..0cd5d9d437 100644
--- a/actionpack/lib/action_view/render/rendering.rb
+++ b/actionpack/lib/action_view/render/rendering.rb
@@ -10,6 +10,7 @@ module ActionView
     # * <tt>:file</tt> - Renders an explicit template file (this used to be the old default), add :locals to pass in those.
     # * <tt>:inline</tt> - Renders an inline template similar to how it's done in the controller.
     # * <tt>:text</tt> - Renders the text passed in out.
+    # * <tt>:once</tt> - Receives :template paths and ensures they are rendered just once.
     #
     # If no options hash is passed or :update specified, the default is to render a partial and use the second parameter
     # as the locals hash.
@@ -20,6 +21,8 @@ module ActionView
           _render_partial(options.merge(:partial => options[:layout]), &block)
         elsif options.key?(:partial)
           _render_partial(options)
+        elsif options.key?(:once)
+          _render_once(options)
         else
           _render_template(options)
         end
@@ -88,6 +91,10 @@ module ActionView
       end
     end
 
+    def _render_once(options) #:nodoc:
+      _template_renderer.render_once(options)
+    end
+
     def _render_template(options) #:nodoc:
       _template_renderer.render(options)
     end