Fix the shortcut form of #render (#25)

* Provide :_reverse_mapping in the renderer proc

* Directly extend ActionController with class methods

* Add a note stating that the proc is evaluated in the controller context

Author: smaximov

lib/jsonapi/rails/action_controller.rb

@@ -6,17 +6,6 @@ module Rails
     module ActionController
       REVERSE_MAPPING_KEY = 'jsonapi_deserializable.reverse_mapping'.freeze
 
-      def self.prepended(base)
-        base.class_eval do
-          extend ClassMethods
-        end
-      end
-
-      def render(options = {})
-        reverse_mapping = request.env[REVERSE_MAPPING_KEY]
-        super(options.merge(_reverse_mapping: reverse_mapping))
-      end
-
       module ClassMethods
         def deserializable_resource(key, options = {}, &block)
           _deserializable(key, options,

lib/jsonapi/rails/railtie.rb

@@ -17,7 +17,7 @@ class Railtie < ::Rails::Railtie
       initializer 'jsonapi-rails.action_controller' do
         ActiveSupport.on_load(:action_controller) do
           require 'jsonapi/rails/action_controller'
-          prepend ::JSONAPI::Rails::ActionController
+          extend ::JSONAPI::Rails::ActionController::ClassMethods
 
           Mime::Type.register MEDIA_TYPE, :jsonapi
 

lib/jsonapi/rails/renderer.rb

@@ -28,6 +28,10 @@ def self.render(errors, options)
     # @api private
     def rails_renderer(renderer)
       proc do |json, options|
+        # Renderer proc is evaluated in the controller context, so it
+        # has access to the request object.
+        reverse_mapping = request.env[ActionController::REVERSE_MAPPING_KEY]
+        options = options.merge(_reverse_mapping: reverse_mapping)
         json = renderer.render(json, options) unless json.is_a?(String)
         self.content_type ||= Mime[:jsonapi]
         self.response_body = json