Remove Rails dependency

Move configuration into a Railtie.
Only dependency is now activemodel

active_model_serializers.gemspec

@@ -13,5 +13,7 @@ Gem::Specification.new do |gem|
   gem.require_paths = ["lib"]
   gem.version       = "0.0.1"
 
-  gem.add_dependency "rails", "~> 3.0"
+  gem.add_dependency 'activemodel', '~> 3.0'
+
+  gem.add_development_dependency "rails", "~> 3.0"
 end

lib/active_model_serializers.rb

@@ -23,12 +23,10 @@ ActiveModel::Serialization.class_eval do
   end
 end
 
-require "action_controller"
-
-module ActionController
-  autoload :Serialization, "action_controller/serialization"
-end
-
-ActiveSupport.on_load(:action_controller) do
-  include ::ActionController::Serialization
+begin
+  require 'action_controller'
+  require 'rails'
+  require 'railtie'
+rescue LoadError => ex
+  # rails on installed, continuing
 end

lib/railtie.rb

@@ -0,0 +1,14 @@
+require 'active_model_serializers'
+require 'action_controller/serialization'
+
+module ActiveModel
+  module Serialization
+    class Railtie < ::Rails::Railtie
+      initializer "active_model.serialization.action_controller" do
+        ActiveSupport.on_load(:action_controller) do
+          include ::ActionController::Serilization
+        end
+      end
+    end
+  end
+end

test/generators_test.rb

@@ -1,4 +1,4 @@
-require 'rails'
+require 'test_helper'
 
 class Foo < Rails::Application
 end

test/serialization_test.rb

@@ -39,6 +39,8 @@ class RenderJsonTest < ActionController::TestCase
   end
 
   class TestController < ActionController::Base
+    include ActionController::Serialization
+
     protect_from_forgery
 
     serialization_scope :current_user