Improve imports if not django_filters installed. Improved Django command fixing warning in Django 1.8+

graphene/contrib/django/fields.py

@@ -4,7 +4,7 @@ from ...core.types.base import FieldType
 from ...core.types.definitions import List
 from ...relay import ConnectionField
 from ...relay.utils import is_node
-from .utils import get_type_for_model, maybe_queryset
+from .utils import get_type_for_model, maybe_queryset, DJANGO_FILTER_INSTALLED
 
 
 class DjangoConnectionField(ConnectionField):
@@ -37,6 +37,7 @@ class DjangoConnectionField(ConnectionField):
 class ConnectionOrListField(Field):
 
     def internal_type(self, schema):
+        if DJANGO_FILTER_INSTALLED:
             from .filter.fields import DjangoFilterConnectionField
 
         model_field = self.type

graphene/contrib/django/filter/__init__.py

@@ -1,11 +1,12 @@
+import warnings
 from graphene.contrib.django.utils import DJANGO_FILTER_INSTALLED
 
 if not DJANGO_FILTER_INSTALLED:
-    raise Exception(
+    warnings.warn(
         "Use of django filtering requires the django-filter package "
-        "be installed. You can do so using `pip install django-filter`"
+        "be installed. You can do so using `pip install django-filter`", ImportWarning
     )
-
+else:
     from .fields import DjangoFilterConnectionField
     from .filterset import GrapheneFilterSet, GlobalIDFilter, GlobalIDMultipleChoiceFilter
 

graphene/contrib/django/management/commands/graphql_schema.py

@@ -1,14 +1,15 @@
 import importlib
 import json
 from optparse import make_option
+from distutils.version import StrictVersion
 
+from django import get_version as get_django_version
 from django.core.management.base import BaseCommand, CommandError
 
+LT_DJANGO_1_8 = StrictVersion(get_django_version()) < StrictVersion('1.8')
 
-class Command(BaseCommand):
-    help = 'Dump Graphene schema JSON to file'
-    can_import_settings = True
-
+if LT_DJANGO_1_8:
+    class CommandArguments(BaseCommand):
         option_list = BaseCommand.option_list + (
             make_option(
                 '--schema',
@@ -25,7 +26,8 @@ class Command(BaseCommand):
                 help='Output file (default: schema.json)'
             ),
         )
-
+else:
+    class CommandArguments(BaseCommand):
         def add_arguments(self, parser):
             from django.conf import settings
             parser.add_argument(
@@ -42,6 +44,11 @@ class Command(BaseCommand):
                 default=getattr(settings, 'GRAPHENE_SCHEMA_OUTPUT', 'schema.json'),
                 help='Output file (default: schema.json)')
 
+
+class Command(CommandArguments):
+    help = 'Dump Graphene schema JSON to file'
+    can_import_settings = True
+
     def save_file(self, out, schema_dict):
         with open(out, 'w') as outfile:
             json.dump(schema_dict, outfile)

graphene/contrib/django/utils.py

@@ -9,7 +9,8 @@ from .compat import RelatedObject
 try:
     import django_filters  # noqa
     DJANGO_FILTER_INSTALLED = True
-except ImportError:
+except (ImportError, AttributeError):
+    # AtributeError raised if DjangoFilters installed with a incompatible Django Version
     DJANGO_FILTER_INSTALLED = False