4 files changed, 28 insertions, 5 deletions
diff --git a/actionpack/lib/action_controller.rb b/actionpack/lib/action_controller.rb
index 3d3af555c9..40f33a9de0 100644
--- a/actionpack/lib/action_controller.rb
+++ b/actionpack/lib/action_controller.rb
@@ -41,6 +41,10 @@ module ActionController
     autoload :UrlFor
   end
 
+  autoload_under "api" do
+    autoload :ApiRendering
+  end
+
   autoload :TestCase,           'action_controller/test_case'
   autoload :TemplateAssertions, 'action_controller/test_case'
 
diff --git a/actionpack/lib/action_controller/api.rb b/actionpack/lib/action_controller/api.rb
index 1a46d49a49..ff12705abe 100644
--- a/actionpack/lib/action_controller/api.rb
+++ b/actionpack/lib/action_controller/api.rb
@@ -112,7 +112,7 @@ module ActionController
 
       UrlFor,
       Redirecting,
-      Rendering,
+      ApiRendering,
       Renderers::All,
       ConditionalGet,
       BasicImplicitRender,
diff --git a/actionpack/lib/action_controller/api/api_rendering.rb b/actionpack/lib/action_controller/api/api_rendering.rb
new file mode 100644
index 0000000000..3a08d28c39
--- /dev/null
+++ b/actionpack/lib/action_controller/api/api_rendering.rb
@@ -0,0 +1,14 @@
+module ActionController
+  module ApiRendering
+    extend ActiveSupport::Concern
+
+    included do
+      include Rendering
+    end
+
+    def render_to_body(options = {})
+      _process_options(options)
+      super
+    end
+  end
+end
diff --git a/actionpack/lib/action_controller/metal/mime_responds.rb b/actionpack/lib/action_controller/metal/mime_responds.rb
index 6e346fadfe..173a14a1d2 100644
--- a/actionpack/lib/action_controller/metal/mime_responds.rb
+++ b/actionpack/lib/action_controller/metal/mime_responds.rb
@@ -9,6 +9,13 @@ module ActionController #:nodoc:
     #     @people = Person.all
     #   end
     #
+    # That action implicitly responds to all formats, but formats can also be whitelisted:
+    #
+    #   def index
+    #     @people = Person.all
+    #     respond_to :html, :js
+    #   end
+    #
     # Here's the same action, with web-service support baked in:
     #
     #   def index
@@ -16,11 +23,12 @@ module ActionController #:nodoc:
     #
     #     respond_to do |format|
     #       format.html
+    #       format.js
     #       format.xml { render xml: @people }
     #     end
     #   end
     #
-    # What that says is, "if the client wants HTML in response to this action, just respond as we
+    # What that says is, "if the client wants HTML or JS in response to this action, just respond as we
     # would have before, but if the client wants XML, return them the list of people in XML format."
     # (Rails determines the desired response format from the HTTP Accept header submitted by the client.)
     #
@@ -180,9 +188,6 @@ module ActionController #:nodoc:
     #     format.html.none
     #     format.html.phone # this gets rendered
     #   end
-    #
-    # Be sure to check the documentation of <tt>ActionController::MimeResponds.respond_to</tt>
-    # for more examples.
     def respond_to(*mimes)
       raise ArgumentError, "respond_to takes either types or a block, never both" if mimes.any? && block_given?