Merge pull request #17 from Saritasa/feature/search-instance-by-uuid

Fix problem for update models with UUID id fields

CHANGELOG.md

@@ -1,4 +1,5 @@
 ## 0.2.1
+* Fix problem for updating models with UUID primary key field (@kseniyashaydurova)
 * Fix problem with raising Protected Error in deletion (@kseniyashaydurova)
 
 ## 0.2.0

drf_writable_nested/mixins.py

@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+import uuid
 from collections import OrderedDict, defaultdict
 
 from django.contrib.contenttypes.fields import GenericRelation
@@ -71,7 +72,8 @@ def _get_serializer_for_field(self, field, **kwargs):
 
     def _get_generic_lookup(self, instance, related_field):
         return {
-            related_field.content_type_field_name: ContentType.objects.get_for_model(instance),
+            related_field.content_type_field_name: 
+                ContentType.objects.get_for_model(instance),
             related_field.object_id_field_name: instance.pk,
         }
 
@@ -82,17 +84,23 @@ def prefetch_related_instances(self, field, related_data):
             pk = self._get_related_pk(d, model_class)
             if pk:
                 pk_list.append(pk)
+
         instances = {
-            related_instance.pk: related_instance
+            str(related_instance.pk): related_instance
             for related_instance in model_class.objects.filter(
-                pk__in=pk_list,
+                pk__in=pk_list
             )
         }
+
         return instances
 
     def _get_related_pk(self, data, model_class):
-        return data.get('pk') or \
-               data.get(model_class._meta.pk.attname)
+        pk = data.get('pk') or data.get(model_class._meta.pk.attname)
+
+        if pk:
+            return str(pk)
+
+        return None
 
     def update_or_create_reverse_relations(self, instance, reverse_relations):
         # Update or create reverse relations:
@@ -158,6 +166,7 @@ def update_or_create_direct_relations(self, attrs, relations):
 
     def save(self, **kwargs):
         self.save_kwargs = defaultdict(dict, kwargs)
+
         return super(BaseNestedModelSerializer, self).save(**kwargs)
 
     def get_save_kwargs(self, field_name):
@@ -166,6 +175,7 @@ def get_save_kwargs(self, field_name):
             raise TypeError(
                 _("Arguments to nested serializer's `save` must be dict's")
             )
+
         return save_kwargs
 
 
@@ -240,7 +250,8 @@ def delete_reverse_relations_if_need(self, instance, reverse_relations):
                     related_field.rel.name: instance,
                 }
             elif isinstance(related_field, GenericRelation):
-                related_field_lookup = self._get_generic_lookup(instance, related_field)
+                related_field_lookup = \
+                    self._get_generic_lookup(instance, related_field)
             else:
                 related_field_lookup = {
                     related_field.name: instance,

tests/models.py

@@ -1,3 +1,4 @@
+import uuid
 from django.contrib.contenttypes.fields import GenericForeignKey, GenericRelation
 from django.contrib.contenttypes.models import ContentType
 from django.db import models
@@ -59,3 +60,13 @@ class CustomPK(models.Model):
         on_delete=models.CASCADE,
         related_name='custompks',
     )
+
+
+class Message(models.Model):
+    id = models.UUIDField(
+        primary_key=True,
+        default=uuid.uuid4,
+        editable=False
+    )
+    profile = models.ForeignKey(Profile, related_name='messages')
+    message = models.CharField(max_length=100)

tests/serializers.py

@@ -12,6 +12,13 @@ class Meta:
         fields = ('pk', 'image',)
 
 
+class MessageSerializer(serializers.ModelSerializer):
+
+    class Meta:
+        model = models.Message
+        fields = ('pk', 'message',)
+
+
 class SiteSerializer(serializers.ModelSerializer):
     url = serializers.CharField()
 
@@ -37,9 +44,12 @@ class ProfileSerializer(WritableNestedModelSerializer):
     # Direct FK relation
     access_key = AccessKeySerializer(allow_null=True)
 
+    # Reverse FK relation with UUID
+    messages = MessageSerializer(many=True)
+
     class Meta:
         model = models.Profile
-        fields = ('pk', 'sites', 'avatars', 'access_key',)
+        fields = ('pk', 'sites', 'avatars', 'access_key', 'messages',)
 
 
 class UserSerializer(WritableNestedModelSerializer):

tests/test_writable_nested_model_serializer.py

@@ -1,3 +1,4 @@
+import uuid
 from rest_framework.exceptions import ValidationError
 from django.test import TestCase
 
@@ -31,6 +32,17 @@ def get_initial_data(self):
                         'image': 'image-2.png',
                     },
                 ],
+                'messages': [
+                    {
+                        'message': 'Message 1'
+                    },
+                    {
+                        'message': 'Message 2'
+                    },
+                    {
+                        'message': 'Message 3'
+                    },
+                ]
             },
         }
 
@@ -111,11 +123,14 @@ def test_update(self):
         self.assertEqual(models.Profile.objects.count(), 1)
         self.assertEqual(models.Site.objects.count(), 2)
         self.assertEqual(models.Avatar.objects.count(), 2)
+        self.assertEqual(models.Message.objects.count(), 3)
 
         # Update
         user_pk = user.pk
         profile_pk = user.profile.pk
 
+        message_to_update_str_pk = str(user.profile.messages.first().pk)
+        message_to_update_pk = user.profile.messages.last().pk
         serializer = serializers.UserSerializer(
             instance=user,
             data={
@@ -141,6 +156,19 @@ def test_update(self):
                             'image': 'new-image-2.png',
                         },
                     ],
+                    'messages': [
+                        {
+                            'pk': message_to_update_str_pk,
+                            'message': 'Old message 1'
+                        },
+                        {
+                            'pk': message_to_update_pk,
+                            'message': 'Old message 2'
+                        },
+                        {
+                            'message': 'New message 1'
+                        }
+                    ],
                 },
             },
         )
@@ -166,12 +194,27 @@ def test_update(self):
             set(profile.avatars.values_list('image', flat=True)),
             {'old-image-1.png', 'new-image-1.png', 'new-image-2.png'}
         )
+        self.assertSetEqual(
+            set(profile.messages.values_list('message', flat=True)),
+            {'Old message 1', 'Old message 2', 'New message 1'}
+        )
+        # Check that message which supposed to be updated still in profile
+        # messages (new message wasn't created instead of update)
+        self.assertIn(
+            message_to_update_pk,
+            profile.messages.values_list('id', flat=True)
+        )
+        self.assertIn(
+            uuid.UUID(message_to_update_str_pk),
+            profile.messages.values_list('id', flat=True)
+        )
 
         # Check instances count
         self.assertEqual(models.User.objects.count(), 1)
         self.assertEqual(models.Profile.objects.count(), 1)
         self.assertEqual(models.Site.objects.count(), 1)
         self.assertEqual(models.Avatar.objects.count(), 3)
+        self.assertEqual(models.Message.objects.count(), 3)
         # Access key shouldn't be removed because it is FK
         self.assertEqual(models.AccessKey.objects.count(), 1)
 
@@ -197,6 +240,7 @@ def test_update_raise_protected_error(self):
                         'image': 'new-image-1.png',
                     },
                 ],
+                'messages': [],
             }
         )