Do not fail when JSON engine is not found

and fallback to default

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## 0.1.2 (unreleased)
   * Add RablRails#render method (see README or source code)
+  * Fix fail when JSON engine is not found. Now fallback to MultiJson.default_adapter
 
 ## 0.1.1
 

lib/rabl-rails.rb

@@ -29,15 +29,13 @@ module RablRails
 
   def self.configure
     yield self
-    post_configure
   end
 
   def self.cache_templates?
     ActionController::Base.perform_caching && @@cache_templates
   end
-
-  private
-  def self.post_configure
-    MultiJson.engine = self.json_engine 
+  
+  def self.set_conversion_engines!
+    MultiJson.use(self.json_engine) rescue nil
   end
 end

lib/rabl-rails/railtie.rb

@@ -3,6 +3,7 @@ module RablRails
     initializer "rabl.initialize" do |app|
       ActiveSupport.on_load(:action_view) do
         ActionView::Template.register_template_handler :rabl, RablRails::Handlers::Rabl
+        RablRails.set_conversion_engines!
       end
     end
   end