Reinstate Base#render_to_string. Introduce AbstractController#render_to_string which stringifies render_to_body.

actionpack/lib/action_controller/abstract/renderer.rb

@@ -20,7 +20,7 @@ module AbstractController
       self.response_body = render_to_body(options)
     end
     
-    # Raw rendering of a template.
+    # Raw rendering of a template to a Rack-compatible body.
     # ====
     # @option _prefix<String> The template's path prefix
     # @option _layout<String> The relative path to the layout template to use
@@ -33,6 +33,16 @@ module AbstractController
       _render_template(template, options)
     end
 
+    # Raw rendering of a template to a string.
+    # ====
+    # @option _prefix<String> The template's path prefix
+    # @option _layout<String> The relative path to the layout template to use
+    # 
+    # :api: plugin
+    def render_to_string(options = {})
+      Rack::Utils.body_to_s(render_to_body(options)).to_ary.join
+    end
+
     def _render_template(template, options)
       _action_view._render_template_with_layout(template)
     end

actionpack/lib/action_controller/base/render.rb

@@ -306,9 +306,9 @@ module ActionController
       (name.is_a?(String) ? name.sub(/^#{controller_path}\//, '') : name).to_s
     end
 
-    # Renders according to the same rules as <tt>render</tt>, but returns the result in a string instead
-    # of sending it as the response body to the browser.
-    def render_to_string(options = nil, &block) #:doc:
+    # Same rules as <tt>render</tt>, but returns a Rack-compatible body
+    # instead of sending the response.
+    def render_to_body(options = nil, &block) #:doc:
       render(options, &block)
       response.body
     ensure
@@ -316,7 +316,11 @@ module ActionController
       erase_render_results
       reset_variables_added_to_assigns
     end
-    
+
+    def render_to_string(options = {})
+      Rack::Utils.body_to_s(render_to_body(options)).to_ary.join
+    end
+
     # Clears the rendered results, allowing for another render to be performed.
     def erase_render_results #:nodoc:
       response.body = []
@@ -387,4 +391,4 @@ module ActionController
       render_for_parts(parts, layout, options)
     end
   end
-end
+end

actionpack/test/abstract_controller/abstract_controller_test.rb

@@ -56,6 +56,14 @@ module AbstractController
       def naked_render
         render
       end
+
+      def rendering_to_body
+        render_to_body "naked_render.erb"
+      end
+
+      def rendering_to_string
+        render_to_string "naked_render.erb"
+      end
     end
     
     class TestRenderer < ActiveSupport::TestCase
@@ -73,6 +81,16 @@ module AbstractController
         result = Me2.process(:naked_render)
         assert_equal "Hello from naked_render.erb", result.response_obj[:body]
       end
+
+      test "rendering to a rack body" do
+        result = Me2.process(:rendering_to_body)
+        assert_equal "Hello from naked_render.erb", result.response_obj[:body]
+      end
+
+      test "rendering to a string" do
+        result = Me2.process(:rendering_to_string)
+        assert_equal "Hello from naked_render.erb", result.response_obj[:body]
+      end
     end
     
     # Test rendering with prefixes