1 files changed, 14 insertions, 3 deletions
diff --git a/activesupport/lib/active_support/json.rb b/activesupport/lib/active_support/json.rb
index 7d5304ddd4..d1203bd21b 100644
--- a/activesupport/lib/active_support/json.rb
+++ b/activesupport/lib/active_support/json.rb
@@ -4,14 +4,20 @@ module ActiveSupport
   module JSON #:nodoc:
     class CircularReferenceError < StandardError #:nodoc:
     end
-    # returns the literal string as its JSON encoded form.  Useful for passing javascript variables into functions.
-    #
-    # page.call 'Element.show', ActiveSupport::JSON::Variable.new("$$(#items li)")
+    
+    # A string that returns itself as as its JSON-encoded form.
     class Variable < String #:nodoc:
       def to_json
         self
       end
     end
+    
+    # When +true+, Hash#to_json will omit quoting string or symbol keys
+    # if the keys are valid JavaScript identifiers.  Note that this is
+    # technically improper JSON (all object keys must be quoted), so if
+    # you need strict JSON compliance, set this option to +false+.
+    mattr_accessor :unquote_hash_key_identifiers
+    @@unquote_hash_key_identifiers = true
 
     class << self
       REFERENCE_STACK_VARIABLE = :json_reference_stack
@@ -22,6 +28,11 @@ module ActiveSupport
         end
       end
       
+      def can_unquote_identifier?(key)
+        return false unless unquote_hash_key_identifiers
+        key.to_s =~ /^[[:alpha:]_$][[:alnum:]_$]*$/
+      end
+      
       protected
         def raise_on_circular_reference(value)
           stack = Thread.current[REFERENCE_STACK_VARIABLE] ||= []