1 files changed, 11 insertions, 3 deletions
diff --git a/activesupport/lib/active_support/json/encoders/hash.rb b/activesupport/lib/active_support/json/encoders/hash.rb
index 9a9f074847..14b91a76a1 100644
--- a/activesupport/lib/active_support/json/encoders/hash.rb
+++ b/activesupport/lib/active_support/json/encoders/hash.rb
@@ -1,8 +1,16 @@
 class Hash
-  def to_json #:nodoc:
+  def to_json(options = {}) #:nodoc:
+    hash_keys = self.keys
+
+    if options[:except]
+      hash_keys = hash_keys - Array(options[:except])
+    elsif options[:only]
+      hash_keys = hash_keys & Array(options[:only])
+    end
+
     returning result = '{' do
-      result << map do |key, value|
-        "#{ActiveSupport::JSON.encode(key)}: #{ActiveSupport::JSON.encode(value)}"
+      result << hash_keys.map do |key|
+        "#{ActiveSupport::JSON.encode(key)}: #{ActiveSupport::JSON.encode(self[key], options)}"
       end * ', '
       result << '}'
     end