Issue googleapis#142 CredentialField Python3 fix

oauth2client/django_orm.py

@@ -21,6 +21,7 @@
 import oauth2client
 import base64
 import pickle
+import six
 
 from django.db import models
 from oauth2client.client import Storage as BaseStorage
@@ -29,9 +30,7 @@
 __author__ = '[email protected] (Joe Gregorio)'
 
 
-class CredentialsField(models.Field):
-
-    __metaclass__ = models.SubfieldBase
+class CredentialsField(six.with_metaclass(models.SubfieldBase, models.Field)):
 
     def __init__(self, *args, **kwargs):
         if 'null' not in kwargs:
@@ -46,12 +45,18 @@ def to_python(self, value):
             return None
         if isinstance(value, oauth2client.client.Credentials):
             return value
+        if isinstance(value, six.text_type):
+            value = value.encode('utf-8')
         return pickle.loads(base64.b64decode(value))
 
-    def get_db_prep_value(self, value, connection, prepared=False):
+    def get_prep_value(self, value):
         if value is None:
             return None
-        return base64.b64encode(pickle.dumps(value))
+        return base64.b64encode(pickle.dumps(value)).decode('utf-8')
+
+    def value_to_string(self, obj):
+        value = self._get_val_from_obj(obj)
+        return self.get_prep_value(value)
 
 
 class FlowField(models.Field):

tests/test_django_orm.py

@@ -61,7 +61,7 @@ def test_field_unpickled(self):
     def test_field_pickled(self):
         prep_value = self.field.get_db_prep_value(self.credentials,
                                                   connection=None)
-        self.assertEqual(prep_value, self.pickle)
+        self.assertEqual(prep_value.encode('utf-8'), self.pickle)
 
 
 class TestFlowField(unittest.TestCase):