Move template handler registration into railtie

lib/jbuilder.rb

@@ -314,6 +314,5 @@ def _blank?(value=@attributes)
   end
 end
 
-require 'jbuilder/jbuilder_template' if defined?(ActionView::Template)
 require 'jbuilder/dependency_tracker'
-require 'jbuilder/railtie' if defined?(Rails::VERSION::MAJOR) && Rails::VERSION::MAJOR == 4
+require 'jbuilder/railtie' if defined?(Rails)

lib/jbuilder/jbuilder_template.rb

@@ -137,5 +137,3 @@ def self.call(template)
       json.target! unless (__already_defined && __already_defined != "method")}
   end
 end
-
-ActionView::Template.register_template_handler :jbuilder, JbuilderHandler

lib/jbuilder/railtie.rb

@@ -1,11 +1,20 @@
 require 'rails/railtie'
+require 'jbuilder/jbuilder_template'
 
 class Jbuilder
   class Railtie < ::Rails::Railtie
-    generators do |app|
-      Rails::Generators.configure! app.config.generators
-      Rails::Generators.hidden_namespaces.uniq!
-      require 'generators/rails/scaffold_controller_generator'
+    initializer :jbuilder do |app|
+      ActiveSupport.on_load :action_view do
+        ActionView::Template.register_template_handler :jbuilder, JbuilderHandler
+      end
+    end
+
+    if Rails::VERSION::MAJOR == 4
+      generators do |app|
+        Rails::Generators.configure! app.config.generators
+        Rails::Generators.hidden_namespaces.uniq!
+        require 'generators/rails/scaffold_controller_generator'
+      end
     end
   end
-end
+end

test/jbuilder_template_test.rb

@@ -5,7 +5,6 @@
 require 'active_support/cache'
 require 'jbuilder/jbuilder_template'
 
-
 BLOG_POST_PARTIAL = <<-JBUILDER
   json.extract! blog_post, :id, :body
   json.author do
@@ -25,6 +24,8 @@
 BLOG_POST_COLLECTION = 10.times.map{ |i| BlogPost.new(i+1, "post body #{i+1}", blog_authors.next) }
 COLLECTION_COLLECTION = 5.times.map{ |i| Collection.new(i+1, "collection #{i+1}") }
 
+ActionView::Template.register_template_handler :jbuilder, JbuilderHandler
+
 module Rails
   def self.cache
     @cache ||= ActiveSupport::Cache::MemoryStore.new