Include layout when rendering objects from controllers

In https://github.com/rails/rails/pull/37919, support
for rendering objects that respond_to render_in in
controllers was added. However, the implementation
did not support layouts.

This change updates the implementation from #37919
to more closely match the rest of the
ActionView::Template classes, enabling the use of layouts.

Co-authored-by: Felipe Sateler <fsateler@gmail.com>

actionpack/test/controller/new_base/render_layout_test.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require "abstract_unit"
+require "test_renderable"
 
 module ControllerLayouts
   class ImplicitController < ::ApplicationController
@@ -19,6 +20,10 @@ module ControllerLayouts
       render template: "basic", layout: "override"
     end
 
+    def override_renderable
+      render TestRenderable.new, layout: "override"
+    end
+
     def layout_false
       render layout: false
     end
@@ -36,6 +41,10 @@ module ControllerLayouts
     def index
       render template: "basic"
     end
+
+    def renderable
+      render TestRenderable.new
+    end
   end
 
   class RenderLayoutTest < Rack::TestCase
@@ -53,6 +62,20 @@ module ControllerLayouts
       assert_status 200
     end
 
+    test "rendering a renderable object, using the implicit layout" do
+      get "/controller_layouts/implicit_name/renderable"
+
+      assert_body "Implicit Hello, World! Layout"
+      assert_status 200
+    end
+
+    test "rendering a renderable object, using the override layout" do
+      get "/controller_layouts/implicit/override_renderable"
+
+      assert_body "Override! Hello, World!"
+      assert_status 200
+    end
+
     test "overriding an implicit layout with render :layout option" do
       get "/controller_layouts/implicit/override"
       assert_body "Override! Hello world!"

actionpack/test/controller/renderer_test.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 require "abstract_unit"
-require "test_component"
+require "test_renderable"
 
 class RendererTest < ActiveSupport::TestCase
   test "action controller base has a renderer" do
@@ -66,12 +66,12 @@ class RendererTest < ActiveSupport::TestCase
     assert_equal "The secret is foo\n", content
   end
 
-  def test_render_component
+  test "render a renderable object" do
     renderer = ApplicationController.renderer
 
     assert_equal(
       %(Hello, World!),
-      renderer.render(TestComponent.new)
+      renderer.render(TestRenderable.new)
     )
   end
 

actionpack/test/lib/test_renderable.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class TestComponent
+class TestRenderable
   def render_in(_view_context)
     "Hello, World!"
   end

actionview/lib/action_view/renderer/renderer.rb

@@ -25,9 +25,6 @@ module ActionView
     def render_to_object(context, options) # :nodoc:
       if options.key?(:partial)
         render_partial_to_object(context, options)
-      elsif options.key?(:object)
-        object = options[:object]
-        AbstractRenderer::RenderedTemplate.new(object.render_in(context), object)
       else
         render_template_to_object(context, options)
       end

actionview/lib/action_view/renderer/template_renderer.rb

@@ -37,6 +37,8 @@ module ActionView
             @lookup_context.formats.first
           end
           Template::Inline.new(options[:inline], "inline template", handler, locals: keys, format: format)
+        elsif options.key?(:renderable)
+          Template::Renderable.new(options[:renderable])
         elsif options.key?(:template)
           if options[:template].respond_to?(:render)
             options[:template]

actionview/lib/action_view/rendering.rb

@@ -145,7 +145,7 @@ module ActionView
           if action.respond_to?(:permitted?) && action.permitted?
             options = action
           elsif action.respond_to?(:render_in)
-            options[:object] = action
+            options[:renderable] = action
           else
             options[:partial] = action
           end

actionview/lib/action_view/template.rb

@@ -111,6 +111,7 @@ module ActionView
     eager_autoload do
       autoload :Error
       autoload :RawFile
+      autoload :Renderable
       autoload :Handlers
       autoload :HTML
       autoload :Inline

actionview/lib/action_view/template/renderable.rb

@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+module ActionView
+  # = Action View Renderable Template for objects that respond to #render_in
+  class Template
+    class Renderable # :nodoc:
+      def initialize(renderable)
+        @renderable = renderable
+      end
+
+      def identifier
+        @renderable.class.name
+      end
+
+      def render(context, *args)
+        @renderable.render_in(context)
+      end
+
+      def format
+        @renderable.format
+      end
+    end
+  end
+end

actionview/test/lib/test_renderable.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-class TestComponent
+class TestRenderable
   def render_in(_view_context)
     "Hello, World!"
   end

actionview/test/template/render_test.rb

@@ -2,7 +2,7 @@
 
 require "abstract_unit"
 require "controller/fake_models"
-require "test_component"
+require "test_renderable"
 require "active_model/validations"
 
 class TestController < ActionController::Base
@@ -331,7 +331,7 @@ module RenderTestCases
     assert_match(/`undefined' for #<ActionView::Base:0x[0-9a-f]+>/, e.message)
   end
 
-  def test_render_object
+  def test_render_renderable_object
     assert_equal "Hello: david", @view.render(partial: "test/customer", object: Customer.new("david"))
     assert_equal "FalseClass", @view.render(partial: "test/klass", object: false)
     assert_equal "NilClass", @view.render(partial: "test/klass", object: nil)
@@ -697,10 +697,10 @@ module RenderTestCases
     assert_raises(ArgumentError) { ActionView::Template.register_template_handler CustomHandler }
   end
 
-  def test_render_component
+  def test_render_object
     assert_equal(
       %(Hello, World!),
-      @view.render(TestComponent.new)
+      @view.render(TestRenderable.new)
     )
   end
 end

guides/source/layouts_and_rendering.md

@@ -282,7 +282,7 @@ TIP: `send_file` is often a faster and better option if a layout isn't required.
 Rails can render objects responding to `:render_in`.
 
 ```ruby
-render MyComponent.new
+render MyRenderable.new
 ```
 
 This calls `render_in` on the provided object with the current view context.