Merge pull request #103 from AltSchool/feature/auto-defer-many-relations

Feature/auto defer many relations

Author: ryochiji

README.md

@@ -570,6 +570,10 @@ DYNAMIC_REST = {
     # ENABLE_SERIALIZER_OPTIMIZATIONS: enable/disable representation speedups
     'ENABLE_SERIALIZER_OPTIMIZATIONS': True,
 
+    # DEFER_MANY_RELATIONS: automatically defer many-relations, unless 
+    # `deferred=False` is explicitly set on the field.
+    'DEFER_MANY_RELATIONS': False,
+
     # MAX_PAGE_SIZE: global setting for max page size.
     # Can be overriden at the viewset level.
     'MAX_PAGE_SIZE': None,

dynamic_rest/conf.py

@@ -24,6 +24,10 @@
     # ENABLE_BULK_UPDATE: enable/disable update in bulk
     'ENABLE_BULK_UPDATE': True,
 
+    # DEFER_MANY_RELATIONS: automatically defer many-relations, unless
+    # `deferred=False` is explicitly set on the field.
+    'DEFER_MANY_RELATIONS': False,
+
     # MAX_PAGE_SIZE: global setting for max page size.
     # Can be overriden at the viewset level.
     'MAX_PAGE_SIZE': None,

dynamic_rest/constants.py

@@ -5,4 +5,4 @@
 REPO_NAME = "dynamic-rest"
 PROJECT_NAME = "Dynamic REST"
 ORG_NAME = "AltSchool"
-VERSION = "1.4.5"
+VERSION = "1.4.6"

dynamic_rest/fields/fields.py

@@ -24,7 +24,7 @@ class DynamicField(fields.Field):
     def __init__(
         self,
         requires=None,
-        deferred=False,
+        deferred=None,
         field_type=None,
         immutable=False,
         **kwargs
@@ -103,7 +103,7 @@ def __init__(
         if 'link' in kwargs:
             self.link = kwargs.pop('link')
         super(DynamicRelationField, self).__init__(**kwargs)
-        self.kwargs['many'] = many
+        self.kwargs['many'] = self.many = many
 
     def get_model(self):
         """Get the child serializer's model."""

dynamic_rest/serializers.py

@@ -322,6 +322,22 @@ def _get_flagged_field_names(self, fields, attr, meta_attr=None):
             meta_list
         }
 
+    def _get_deferred_field_names(self, fields):
+        deferred_fields = self._get_flagged_field_names(
+            fields,
+            'deferred'
+        )
+        if settings.DEFER_MANY_RELATIONS:
+            # Auto-defer all fields, unless the 'deferred' attribute
+            # on the field is specifically set to False.
+            many_fields = self._get_flagged_field_names(fields, 'many')
+            deferred_fields.update({
+                name for name in many_fields
+                if getattr(fields[name], 'deferred', None) is not False
+            })
+
+        return deferred_fields
+
     def flag_fields(self, all_fields, fields_to_flag, attr, value):
         for name in fields_to_flag:
             field = all_fields.get(name)
@@ -344,7 +360,7 @@ def get_fields(self):
 
         serializer_fields = copy.deepcopy(all_fields)
         request_fields = self.request_fields
-        deferred = self._get_flagged_field_names(serializer_fields, 'deferred')
+        deferred = self._get_deferred_field_names(serializer_fields)
 
         # apply request overrides
         if request_fields:

tests/serializers.py

@@ -77,8 +77,8 @@ class Meta:
         fields = ('id', 'name', 'code', 'users', 'groups')
         deferred_fields = ('code',)
 
-    users = DynamicRelationField('UserSerializer', many=True, deferred=True)
-    groups = DynamicRelationField('GroupSerializer', many=True, deferred=True)
+    users = DynamicRelationField('UserSerializer', many=True, deferred=False)
+    groups = DynamicRelationField('GroupSerializer', many=True)
 
 
 class GroupSerializer(DynamicModelSerializer):

tests/test_api.py

@@ -6,8 +6,8 @@
 from django.utils import six
 from rest_framework.test import APITestCase
 
-from tests.models import Cat, Group, Location, Profile, User
-from tests.serializers import NestedEphemeralSerializer
+from tests.models import Cat, Group, Location, Permission, Profile, User
+from tests.serializers import NestedEphemeralSerializer, PermissionSerializer
 from tests.setup import create_fixture
 
 UNICODE_STRING = six.unichr(9629)  # unicode heart
@@ -1109,6 +1109,33 @@ def test_meta_read_only_relation_field(self):
         # a 404 since a matching Profile object isn't found.
         self.assertEquals(201, response.status_code)
 
+    @override_settings(
+        DYNAMIC_REST={
+            'ENABLE_LINKS': True,
+            'DEFER_MANY_RELATIONS': True,
+        }
+    )
+    def test_auto_deferral(self):
+        perm = Permission.objects.create(
+            name='test',
+            code=1
+        )
+        perm.groups.add(self.fixture.groups[0])
+
+        # Check serializers
+        fields = PermissionSerializer().get_all_fields()
+        self.assertIs(fields['users'].deferred, False)
+        self.assertIs(fields['groups'].deferred, None)
+
+        url = '/permissions/%s/' % perm.pk
+        r = self.client.get(url)
+        data = json.loads(r.content.decode('utf-8'))
+        self.assertFalse('groups' in data['permission'])
+
+        # users shouldn't be deferred because `deferred=False` is
+        # explicitly set on the field.
+        self.assertTrue('users' in data['permission'])
+
 
 class TestDogsAPI(APITestCase):
 

tests/urls.py

@@ -12,6 +12,7 @@
 router.register(r'cats', viewsets.CatViewSet)
 router.register_resource(viewsets.DogViewSet)
 router.register_resource(viewsets.HorseViewSet)
+router.register_resource(viewsets.PermissionViewSet)
 router.register(r'zebras', viewsets.ZebraViewSet)  # not canonical
 router.register(r'user_locations', viewsets.UserLocationViewSet)
 

tests/viewsets.py

@@ -1,13 +1,24 @@
 from rest_framework import exceptions
 
 from dynamic_rest.viewsets import DynamicModelViewSet
-from tests.models import Cat, Dog, Group, Horse, Location, Profile, User, Zebra
+from tests.models import (
+    Cat,
+    Dog,
+    Group,
+    Horse,
+    Location,
+    Permission,
+    Profile,
+    User,
+    Zebra
+)
 from tests.serializers import (
     CatSerializer,
     DogSerializer,
     GroupSerializer,
     HorseSerializer,
     LocationSerializer,
+    PermissionSerializer,
     ProfileSerializer,
     UserLocationSerializer,
     UserSerializer,
@@ -132,3 +143,8 @@ class ZebraViewSet(DynamicModelViewSet):
     serializer_class = ZebraSerializer
     queryset = Zebra.objects.all()
     ordering_fields = '__all__'
+
+
+class PermissionViewSet(DynamicModelViewSet):
+    serializer_class = PermissionSerializer
+    queryset = Permission.objects.all()