1 files changed, 91 insertions, 0 deletions
diff --git a/actionpack/lib/action_controller/metal/renderers.rb b/actionpack/lib/action_controller/metal/renderers.rb
new file mode 100644
index 0000000000..c1ba47927a
--- /dev/null
+++ b/actionpack/lib/action_controller/metal/renderers.rb
@@ -0,0 +1,91 @@
+module ActionController
+  def self.add_renderer(key, &block)
+    Renderers.add(key, &block)
+  end
+
+  module Renderers
+    extend ActiveSupport::Concern
+
+    included do
+      extlib_inheritable_accessor :_renderers
+      self._renderers = {}
+    end
+
+    module ClassMethods
+      def _write_render_options
+        renderers = _renderers.map do |name, value|
+          <<-RUBY_EVAL
+            if options.key?(:#{name})
+              _process_options(options)
+              return _render_option_#{name}(options[:#{name}], options)
+            end
+          RUBY_EVAL
+        end
+
+        class_eval <<-RUBY_EVAL, __FILE__, __LINE__ + 1
+          def _handle_render_options(options)
+            #{renderers.join}
+          end
+        RUBY_EVAL
+      end
+
+      def use_renderers(*args)
+        args.each do |key|
+          _renderers[key] = RENDERERS[key]
+        end
+        _write_render_options
+      end
+      alias use_renderer use_renderers
+    end
+
+    def render_to_body(options)
+      _handle_render_options(options) || super
+    end
+
+    RENDERERS = {}
+    def self.add(key, &block)
+      define_method("_render_option_#{key}", &block)
+      RENDERERS[key] = block
+      All._write_render_options
+    end
+
+    module All
+      extend ActiveSupport::Concern
+      include Renderers
+
+      INCLUDED = []
+      included do
+        self._renderers = RENDERERS
+        _write_render_options
+        INCLUDED << self
+      end
+
+      def self._write_render_options
+        INCLUDED.each(&:_write_render_options)
+      end
+    end
+
+    add :json do |json, options|
+      json = ActiveSupport::JSON.encode(json) unless json.respond_to?(:to_str)
+      json = "#{options[:callback]}(#{json})" unless options[:callback].blank?
+      self.content_type ||= Mime::JSON
+      self.response_body  = json
+    end
+
+    add :js do |js, options|
+      self.content_type ||= Mime::JS
+      self.response_body  = js.respond_to?(:to_js) ? js.to_js : js
+    end
+
+    add :xml do |xml, options|
+      self.content_type ||= Mime::XML
+      self.response_body  = xml.respond_to?(:to_xml) ? xml.to_xml : xml
+    end
+
+    add :update do |proc, options|
+      generator = ActionView::Helpers::PrototypeHelper::JavaScriptGenerator.new(view_context, &proc)
+      self.content_type = Mime::JS
+      self.response_body = generator.to_s
+    end
+  end
+end