Fixed prefetch_related when using UUIDTaggedItem

taggit/managers.py

@@ -1,3 +1,4 @@
+import uuid
 from operator import attrgetter
 
 from django import VERSION
@@ -17,7 +18,11 @@
 from django.utils.translation import gettext_lazy as _
 
 from taggit.forms import TagField
-from taggit.models import CommonGenericTaggedItemBase, TaggedItem
+from taggit.models import (
+    CommonGenericTaggedItemBase,
+    GenericUUIDTaggedItemBase,
+    TaggedItem,
+)
 from taggit.utils import require_instance_manager
 
 
@@ -102,18 +107,32 @@ def get_prefetch_queryset(self, instances, queryset=None):
                 }
             )
         )
+
+        if issubclass(self.through, GenericUUIDTaggedItemBase):
+
+            def uuid_rel_obj_attr(v):
+                value = attrgetter("_prefetch_related_val")(v)
+                if value is not None and not isinstance(value, uuid.UUID):
+                    input_form = "int" if isinstance(value, int) else "hex"
+                    value = uuid.UUID(**{input_form: value})
+                return value
+
+            rel_obj_attr = uuid_rel_obj_attr
+        else:
+            rel_obj_attr = attrgetter("_prefetch_related_val")
+
         if VERSION < (2, 0):
             return (
                 qs,
-                attrgetter("_prefetch_related_val"),
+                rel_obj_attr,
                 lambda obj: obj._get_pk_val(),
                 False,
                 self.prefetch_cache_name,
             )
         else:
             return (
                 qs,
-                attrgetter("_prefetch_related_val"),
+                rel_obj_attr,
                 lambda obj: obj._get_pk_val(),
                 False,
                 self.prefetch_cache_name,

tests/migrations/0002_auto_20200214_1129.py

@@ -0,0 +1,109 @@
+# Generated by Django 3.0.3 on 2020-02-14 11:29
+
+import uuid
+
+import django.utils.timezone
+from django.db import migrations, models
+
+import taggit.managers
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("taggit", "0003_taggeditem_add_unique_index"),
+        ("contenttypes", "0002_remove_content_type_name"),
+        ("tests", "0001_initial"),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name="UUIDPet",
+            fields=[
+                (
+                    "id",
+                    models.UUIDField(
+                        default=uuid.uuid4,
+                        editable=False,
+                        primary_key=True,
+                        serialize=False,
+                    ),
+                ),
+                ("name", models.CharField(max_length=50)),
+                ("created_at", models.DateTimeField(auto_now_add=True)),
+            ],
+            options={"ordering": ["created_at"]},
+        ),
+        migrations.AlterModelOptions(
+            name="uuidfood", options={"ordering": ["created_at"]},
+        ),
+        migrations.AddField(
+            model_name="blanktagmodel",
+            name="tags",
+            field=taggit.managers.TaggableManager(
+                blank=True,
+                help_text="A comma-separated list of tags.",
+                through="taggit.TaggedItem",
+                to="taggit.Tag",
+                verbose_name="Tags",
+            ),
+        ),
+        migrations.AddField(
+            model_name="uuidfood",
+            name="created_at",
+            field=models.DateTimeField(
+                auto_now_add=True, default=django.utils.timezone.now
+            ),
+            preserve_default=False,
+        ),
+        migrations.AlterField(
+            model_name="taggedtrackedfood",
+            name="tag",
+            field=models.ForeignKey(
+                on_delete=django.db.models.deletion.CASCADE,
+                related_name="taggedtrackedfood_items",
+                to="tests.TrackedTag",
+            ),
+        ),
+        migrations.AlterField(
+            model_name="taggedtrackedpet",
+            name="tag",
+            field=models.ForeignKey(
+                on_delete=django.db.models.deletion.CASCADE,
+                related_name="taggedtrackedpet_items",
+                to="tests.TrackedTag",
+            ),
+        ),
+        migrations.AlterUniqueTogether(
+            name="uuidtaggeditem",
+            unique_together={("content_type", "object_id", "tag")},
+        ),
+        migrations.CreateModel(
+            name="UUIDHousePet",
+            fields=[
+                (
+                    "uuidpet_ptr",
+                    models.OneToOneField(
+                        auto_created=True,
+                        on_delete=django.db.models.deletion.CASCADE,
+                        parent_link=True,
+                        primary_key=True,
+                        serialize=False,
+                        to="tests.UUIDPet",
+                    ),
+                ),
+                ("trained", models.BooleanField(default=False)),
+            ],
+            bases=("tests.uuidpet",),
+        ),
+        migrations.AddField(
+            model_name="uuidpet",
+            name="tags",
+            field=taggit.managers.TaggableManager(
+                help_text="A comma-separated list of tags.",
+                through="tests.UUIDTaggedItem",
+                to="tests.UUIDTag",
+                verbose_name="Tags",
+            ),
+        ),
+    ]

tests/models.py

@@ -332,9 +332,34 @@ class UUIDFood(models.Model):
     name = models.CharField(max_length=50)
     tags = TaggableManager(through="UUIDTaggedItem")
 
+    created_at = models.DateTimeField(auto_now_add=True)
+
+    def __str__(self):
+        return self.name
+
+    class Meta:
+        # With a UUIDField pk, objects are not always ordered by creation time. So explicitly set ordering.
+        ordering = ["created_at"]
+
+
+class UUIDPet(models.Model):
+    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
+    name = models.CharField(max_length=50)
+
+    tags = TaggableManager(through="UUIDTaggedItem")
+    created_at = models.DateTimeField(auto_now_add=True)
+
     def __str__(self):
         return self.name
 
+    class Meta:
+        # With a UUIDField pk, objects are not always ordered by creation time. So explicitly set ordering.
+        ordering = ["created_at"]
+
+
+class UUIDHousePet(UUIDPet):
+    trained = models.BooleanField(default=False)
+
 
 class UUIDTag(TagBase):
     id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
@@ -345,6 +370,9 @@ class UUIDTaggedItem(GenericUUIDTaggedItemBase):
         UUIDTag, related_name="%(app_label)s_%(class)s_items", on_delete=models.CASCADE
     )
 
+    class Meta:
+        unique_together = [["content_type", "object_id", "tag"]]
+
 
 # Exists to verify system check failure.
 # tests.Name.tags: (fields.E303) Reverse query name for 'Name.tags' clashes with field name 'Tag.name'.

tests/tests.py

@@ -49,7 +49,10 @@
     TaggedTrackedFood,
     TrackedTag,
     UUIDFood,
+    UUIDHousePet,
+    UUIDPet,
     UUIDTag,
+    UUIDTaggedItem,
 )
 
 from taggit.managers import TaggableManager, _TaggableManager
@@ -677,13 +680,13 @@ def test_names_method(self):
         apple = self.food_model.objects.create(name="apple")
         apple.tags.add("green")
         apple.tags.add("red")
-        self.assertEqual(list(apple.tags.names()), ["green", "red"])
+        self.assertEqual(sorted(list(apple.tags.names())), ["green", "red"])
 
     def test_slugs_method(self):
         apple = self.food_model.objects.create(name="apple")
         apple.tags.add("green and juicy")
         apple.tags.add("red")
-        self.assertEqual(list(apple.tags.slugs()), ["green-and-juicy", "red"])
+        self.assertEqual(sorted(list(apple.tags.slugs())), ["green-and-juicy", "red"])
 
     def test_serializes(self):
         apple = self.food_model.objects.create(name="apple")
@@ -794,6 +797,19 @@ def test_require_pk(self):
         pass
 
 
+class TaggableManagerUUIDTestCase(TaggableManagerTestCase):
+    food_model = UUIDFood
+    pet_model = UUIDPet
+    housepet_model = UUIDHousePet
+    taggeditem_model = UUIDTaggedItem
+    tag_model = UUIDTag
+
+    def test_require_pk(self):
+        # With a UUIDField pk, pk is never None. So taggit has no way to tell
+        # if the instance is saved or not.
+        pass
+
+
 class TaggableManagerOfficialTestCase(TaggableManagerTestCase):
     food_model = OfficialFood
     pet_model = OfficialPet