Default to null=True for Django Fields.

Fixes issue #161.

Reviewed in http://codereview.appspot.com/6448098/

oauth2client/django_orm.py

@@ -31,6 +31,11 @@ class CredentialsField(models.Field):
 
   __metaclass__ = models.SubfieldBase
 
+  def __init__(self, *args, **kwargs):
+    if 'null' not in kwargs:
+      kwargs['null'] = True
+    super(CredentialsField, self).__init__(*args, **kwargs)
+
   def get_internal_type(self):
     return "TextField"
 
@@ -51,6 +56,11 @@ class FlowField(models.Field):
 
   __metaclass__ = models.SubfieldBase
 
+  def __init__(self, *args, **kwargs):
+    if 'null' not in kwargs:
+      kwargs['null'] = True
+    super(FlowField, self).__init__(*args, **kwargs)
+
   def get_internal_type(self):
     return "TextField"
 

samples/django_sample/settings.py

@@ -10,12 +10,12 @@ ADMINS = (
 
 MANAGERS = ADMINS
 
-DATABASE_ENGINE = 'sqlite3'
-DATABASE_NAME = 'database.sqlite3'
-DATABASE_USER = ''
-DATABASE_PASSWORD = ''
-DATABASE_HOST = ''
-DATABASE_PORT = ''
+DATABASES = {
+    'default': {
+        'ENGINE': 'django.db.backends.sqlite3',
+        'NAME': 'mydatabase'
+        }
+    }
 
 # Local time zone for this installation. Choices can be found here:
 # http://en.wikipedia.org/wiki/List_of_tz_zones_by_name
@@ -53,9 +53,8 @@ SECRET_KEY = '_=9hq-$t_uv1ckf&s!y2$9g$1dm*6p1cl%*!^mg=7gr)!zj32d'
 
 # List of callables that know how to import templates from various sources.
 TEMPLATE_LOADERS = (
-    'django.template.loaders.filesystem.load_template_source',
-    'django.template.loaders.app_directories.load_template_source',
-#     'django.template.loaders.eggs.load_template_source',
+    'django.template.loaders.filesystem.Loader',
+    'django.template.loaders.app_directories.Loader',
 )
 
 MIDDLEWARE_CLASSES = (