Added support for custom JSON serializers

docs/apidocs/index.txt

@@ -70,6 +70,12 @@ functionality of RPC4Django
     allowing cross site requests. See the Mozilla documentation on 
     `preflighted requests`_ for more details. Defaults to the empty string.
 
+.. envvar:: RPC4DJANGO_JSON_OBJECT_SERIALIZER
+
+    This function converts its single argument into object, which could be
+	serialized to JSON, or raises ``TypeError``. Can be used to convert
+	instances of ``datetime.datetime`` into strings with required format.
+
 .. _requests with credentials: https://developer.mozilla.org/en/HTTP_access_control#Requests_with_credentials
 .. _preflighted requests: https://developer.mozilla.org/en/HTTP_access_control#Preflighted_requests
 
@@ -102,4 +108,4 @@ Template tags
 
 .. automodule:: rpc4django.templatetags.rpctags
    :members:
-
+

rpc4django/jsonrpcdispatcher.py

@@ -40,7 +40,8 @@ class JSONRPCDispatcher:
     or error.
     '''
 
-    def __init__(self):
+    def __init__(self, object_serializer):
+        self.object_serializer = object_serializer
         self.methods = {}
 
     def register_function(self, method, external_name):
@@ -63,15 +64,15 @@ def _encode_result(self, jsonid, result, error):
             res['result'] = None
 
         try:
-            return json.dumps(res, indent=JSON_INDENT)
+            return json.dumps(res, indent=JSON_INDENT, default=self.object_serializer)
         except:
             err = {'message': 'failed to encode return value',
                    'code': JSONRPC_SERVICE_ERROR,
                    'name': 'JSONRPCError'}
 
             res['result'] = None
             res['error'] = err
-            return json.dumps(res, indent=JSON_INDENT)
+            return json.dumps(res, indent=JSON_INDENT, default=self.object_serializer)
 
     def dispatch(self, json_data, **kwargs):
         '''
@@ -146,4 +147,4 @@ def dispatch(self, json_data, **kwargs):
                      '" is not supported',  
                      'code': JSONRPC_PROCEDURE_NOT_FOUND_ERROR})
 
-
+

rpc4django/rpcdispatcher.py

@@ -210,11 +210,12 @@ class RPCDispatcher:
       
     '''
 
-    def __init__(self, url='', apps=[], restrict_introspection=False, restrict_ootb_auth=True):
+    def __init__(self, url='', apps=[], restrict_introspection=False,
+            restrict_ootb_auth=True, json_object_serializer=None):
         version = platform.python_version_tuple()
         self.url = url
         self.rpcmethods = []        # a list of RPCMethod objects
-        self.jsonrpcdispatcher = JSONRPCDispatcher()
+        self.jsonrpcdispatcher = JSONRPCDispatcher(json_object_serializer)
         self.xmlrpcdispatcher = XMLRPCDispatcher()
 
         if not restrict_introspection:

rpc4django/views.py

@@ -42,6 +42,8 @@
                                   'RPC4DJANGO_HTTP_ACCESS_CREDENTIALS', False)
 HTTP_ACCESS_ALLOW_ORIGIN = getattr(settings, 
                                   'RPC4DJANGO_HTTP_ACCESS_ALLOW_ORIGIN', '')
+JSON_OBJECT_SERIALIZER = getattr(settings, 
+                                  'RPC4DJANGO_JSON_OBJECT_SERIALIZER', None)
 
 # get a list of the installed django applications
 # these will be scanned for @rpcmethod decorators
@@ -235,5 +237,6 @@ def serve_rpc_request(request):
 
 # instantiate the rpcdispatcher -- this examines the INSTALLED_APPS
 # for any @rpcmethod decorators and adds them to the callable methods
-dispatcher = RPCDispatcher(URL, APPS, RESTRICT_INTROSPECTION, RESTRICT_OOTB_AUTH) 
+dispatcher = RPCDispatcher(URL, APPS, RESTRICT_INTROSPECTION,
+        RESTRICT_OOTB_AUTH, JSON_OBJECT_SERIALIZER)