Add Rails >= 5.0.beta3 JSON API params parsing (#1751)

This reverts commit 6288203277.

lib/active_model_serializers/register_jsonapi_renderer.rb

@@ -22,43 +22,54 @@
 # render jsonapi: model
 #
 # No wrapper format needed as it does not apply (i.e. no `wrap_parameters format: [jsonapi]`)
-
 module ActiveModelSerializers::Jsonapi
   MEDIA_TYPE = 'application/vnd.api+json'.freeze
   HEADERS = {
     response: { 'CONTENT_TYPE'.freeze => MEDIA_TYPE },
     request:  { 'ACCEPT'.freeze => MEDIA_TYPE }
   }.freeze
+
+  def self.install
+    # actionpack/lib/action_dispatch/http/mime_types.rb
+    Mime::Type.register MEDIA_TYPE, :jsonapi
+
+    if Rails::VERSION::MAJOR >= 5
+      ActionDispatch::Request.parameter_parsers[:jsonapi] = parser
+    else
+      ActionDispatch::ParamsParser::DEFAULT_PARSERS[Mime[:jsonapi]] = parser
+    end
+
+    # ref https://github.com/rails/rails/pull/21496
+    ActionController::Renderers.add :jsonapi do |json, options|
+      json = serialize_jsonapi(json, options).to_json(options) unless json.is_a?(String)
+      self.content_type ||= Mime[:jsonapi]
+      self.response_body = json
+    end
+  end
+
+  # Proposal: should actually deserialize the JSON API params
+  # to the hash format expected by `ActiveModel::Serializers::JSON`
+  # actionpack/lib/action_dispatch/http/parameters.rb
+  def self.parser
+    lambda do |body|
+      data = JSON.parse(body)
+      data = { :_json => data } unless data.is_a?(Hash)
+      data.with_indifferent_access
+    end
+  end
+
   module ControllerSupport
     def serialize_jsonapi(json, options)
       options[:adapter] = :json_api
-      options.fetch(:serialization_context) { options[:serialization_context] = ActiveModelSerializers::SerializationContext.new(request) }
+      options.fetch(:serialization_context) do
+        options[:serialization_context] = ActiveModelSerializers::SerializationContext.new(request)
+      end
       get_serializer(json, options)
     end
   end
 end
 
-# actionpack/lib/action_dispatch/http/mime_types.rb
-Mime::Type.register ActiveModelSerializers::Jsonapi::MEDIA_TYPE, :jsonapi
-
-parsers = Rails::VERSION::MAJOR >= 5 ? ActionDispatch::Http::Parameters : ActionDispatch::ParamsParser
-media_type = Mime::Type.lookup(ActiveModelSerializers::Jsonapi::MEDIA_TYPE)
-
-# Proposal: should actually deserialize the JSON API params
-# to the hash format expected by `ActiveModel::Serializers::JSON`
-# actionpack/lib/action_dispatch/http/parameters.rb
-parsers::DEFAULT_PARSERS[media_type] = lambda do |body|
-  data = JSON.parse(body)
-  data = { :_json => data } unless data.is_a?(Hash)
-  data.with_indifferent_access
-end
-
-# ref https://github.com/rails/rails/pull/21496
-ActionController::Renderers.add :jsonapi do |json, options|
-  json = serialize_jsonapi(json, options).to_json(options) unless json.is_a?(String)
-  self.content_type ||= media_type
-  self.response_body = json
-end
+ActiveModelSerializers::Jsonapi.install
 
 ActiveSupport.on_load(:action_controller) do
   include ActiveModelSerializers::Jsonapi::ControllerSupport