JSON Schema Compiler supports Enums as types.

tools/json_schema_compiler/cpp_type_generator.py

Index: tools/json_schema_compiler/cpp_type_generator.py
diff --git a/tools/json_schema_compiler/cpp_type_generator.py b/tools/json_schema_compiler/cpp_type_generator.py
index edfe79fc6707f616dd37923dcaf21bcee90baa11..fc28c60112b8f79f47a5dba679f671c127ecc7f1 100644
--- a/tools/json_schema_compiler/cpp_type_generator.py
+++ b/tools/json_schema_compiler/cpp_type_generator.py
@@ -98,15 +98,20 @@ class CppTypeGenerator(object):
     """Gets the enum value in the given model.Property indicating no value has
     been set.
     """
-    return '%s_NONE' % prop.unix_name.upper()
+    prop_name = prop.unix_name
+    if (self._IsEnumRef(prop)):
+      prop_name = self.GetCompiledType(prop).upper()
+    return '%s_NONE' % prop_name.upper()
 
   def GetEnumValue(self, prop, enum_value):
     """Gets the enum value of the given model.Property of the given type.
 
     e.g VAR_STRING
     """
-    return '%s_%s' % (
-        prop.unix_name.upper(), cpp_util.Classname(enum_value.upper()))
+    prop_name = prop.unix_name.upper()
+    if (self._IsEnumRef(prop)):
+      prop_name = self.GetCompiledType(prop).upper()
+    return '%s_%s' % (prop_name, cpp_util.Classname(enum_value.upper()))
 
   def GetChoicesEnumType(self, prop):
     """Gets the type of the enum for the given model.Property.
@@ -263,6 +268,17 @@ class CppTypeGenerator(object):
     return self._ResolveTypeNamespace(prop.ref_type).types.get(prop.ref_type,
         None)
 
+  def IsEnumOrEnumRef(self, prop):
+    """Returns true if the property is an ENUM or a reference to an ENUM.
+    """
+    return self.GetReferencedProperty(prop).type_ == PropertyType.ENUM
+
+  def _IsEnumRef(self, prop):

[Yoyo Zhou, 2012/08/27 23:56:04]

If you made this public, you wouldn't need to duplicate it in cc_generator.

[chebert, 2012/08/28 21:31:14]

Done.

+    """Returns true if the property is an ENUM or a reference to an ENUM.

[Yoyo Zhou, 2012/08/27 23:56:04]

no

[chebert, 2012/08/28 21:31:14]

Dang. I need to work on my editing.
On 2012/08/27 23:56:04, Yoyo Zhou wrote:

+    """
+    return (self.GetReferencedProperty(prop).type_ == PropertyType.ENUM and
+            prop.type_ != PropertyType.ENUM)

[Yoyo Zhou, 2012/08/27 23:56:04]

I'd put prop.type_ == PropertyType.REF here instead, and actually as the first
condition in the and.

[chebert, 2012/08/28 21:31:14]

Done.

+
   def _NamespaceTypeDependencies(self):
     """Returns a dict containing a mapping of model.Namespace to the C++ type
     of type dependencies for self._namespace.