From cad8fafa601c6a1f1449ec524c027a97fbeb84d4 Mon Sep 17 00:00:00 2001
From: Santiago Pastorino <santiago@wyeworks.com>
Date: Mon, 16 Sep 2013 12:22:23 -0300
Subject: [PATCH] Optimize serializer_for for Ruby >= 2.0

---
 lib/active_model/serializer.rb | 24 +++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)

diff --git a/lib/active_model/serializer.rb b/lib/active_model/serializer.rb
index f0a23381..d89bfb2f 100644
--- a/lib/active_model/serializer.rb
+++ b/lib/active_model/serializer.rb
@@ -22,11 +22,25 @@ module ActiveModel
         SETTINGS[:include] = true if options[:include]
       end
 
-      def serializer_for(resource)
-        if resource.respond_to?(:to_ary)
-          ArraySerializer
-        else
-          "#{resource.class.name}Serializer".safe_constantize
+      if RUBY_VERSION >= '2.0'
+        def serializer_for(resource)
+          if resource.respond_to?(:to_ary)
+            ArraySerializer
+          else
+            begin
+              Object.const_get "#{resource.class.name}Serializer"
+            rescue NameError
+              nil
+            end
+          end
+        end
+      else
+        def serializer_for(resource)
+          if resource.respond_to?(:to_ary)
+            ArraySerializer
+          else
+            "#{resource.class.name}Serializer".safe_constantize
+          end
         end
       end