Add initial implementation for use_natural_foreign_keys support

reversion/models.py

@@ -225,10 +225,12 @@ def _model(self):
 
     @cached_property
     def _object_version(self):
+        version_options = _get_options(self._model)
         data = self.serialized_data
         data = force_str(data.encode("utf8"))
         try:
-            return list(serializers.deserialize(self.format, data, ignorenonexistent=True))[0]
+            return list(serializers.deserialize(self.format, data, ignorenonexistent=True,
+                        use_natural_foreign_keys=version_options.use_natural_foreign_keys))[0]
         except DeserializationError:
             raise RevertError(ugettext("Could not load %(object_repr)s version - incompatible version data.") % {
                 "object_repr": self.object_repr,

reversion/revisions.py

@@ -20,6 +20,7 @@
     "format",
     "for_concrete_model",
     "ignore_duplicates",
+    "use_natural_foreign_keys",
 ))
 
 
@@ -190,6 +191,7 @@ def _add_to_revision(obj, using, model_db, explicit):
             version_options.format,
             (obj,),
             fields=version_options.fields,
+            use_natural_foreign_keys=version_options.use_natural_foreign_keys,
         ),
         object_repr=force_str(obj),
     )
@@ -364,7 +366,7 @@ def _get_senders_and_signals(model):
 
 
 def register(model=None, fields=None, exclude=(), follow=(), format="json",
-             for_concrete_model=True, ignore_duplicates=False):
+             for_concrete_model=True, ignore_duplicates=False, use_natural_foreign_keys=False):
     def register(model):
         # Prevent multiple registration.
         if is_registered(model):
@@ -388,6 +390,7 @@ def register(model):
             format=format,
             for_concrete_model=for_concrete_model,
             ignore_duplicates=ignore_duplicates,
+            use_natural_foreign_keys=use_natural_foreign_keys,
         )
         # Register the model.
         _registered_models[_get_registration_key(model)] = version_options

tests/test_app/migrations/0002_naturalkey.py

@@ -0,0 +1,33 @@
+# Generated by Django 2.2.12 on 2020-08-15 11:42
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('test_app', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='TestModelWithNaturalKey',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('name', models.CharField(default='v1', max_length=191)),
+            ],
+        ),
+        migrations.AlterField(
+            model_name='testmodelnestedinline',
+            name='nested_inline_name',
+            field=models.CharField(default='v1', max_length=191),
+        ),
+        migrations.CreateModel(
+            name='TestModelInlineByNaturalKey',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('test_model', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='test_app.TestModelWithNaturalKey')),
+            ],
+        ),
+    ]

tests/test_app/models.py

@@ -118,3 +118,27 @@ class TestMeta(models.Model):
     name = models.CharField(
         max_length=191,
     )
+
+
+class TestModelWithNaturalKeyManager(models.Manager):
+    def get_by_natural_key(self, name):
+        return self.get(name=name)
+
+
+class TestModelWithNaturalKey(models.Model):
+    name = models.CharField(
+        max_length=191,
+        default="v1",
+    )
+
+    objects = TestModelWithNaturalKeyManager()
+
+    def natural_key(self):
+        return (self.name,)
+
+
+class TestModelInlineByNaturalKey(models.Model):
+    test_model = models.ForeignKey(
+        TestModelWithNaturalKey,
+        on_delete=models.CASCADE,
+    )

tests/test_app/tests/test_models.py

@@ -3,8 +3,10 @@
 from test_app.models import (
     TestModel, TestModelRelated, TestModelParent, TestModelInline,
     TestModelNestedInline,
+    TestModelInlineByNaturalKey, TestModelWithNaturalKey,
 )
 from test_app.tests.base import TestBase, TestModelMixin, TestModelParentMixin
+import json
 
 
 class GetForModelTest(TestModelMixin, TestBase):
@@ -412,3 +414,24 @@ def testRevertDeleteNestedInline(self):
         self.assertEqual(
             list(child_a.testmodelnestedinline_set.all()), [grandchild_a]
         )
+
+
+class NaturalKeyTest(TestBase):
+
+    def setUp(self):
+        reversion.register(TestModelInlineByNaturalKey, use_natural_foreign_keys=True)
+        reversion.register(TestModelWithNaturalKey)
+
+    def testNaturalKeyInline(self):
+        with reversion.create_revision():
+            inline = TestModelWithNaturalKey.objects.create()
+            obj = TestModelInlineByNaturalKey.objects.create(test_model=inline)
+        self.assertEqual(json.loads(Version.objects.get_for_object(obj).get().serialized_data), [{
+            'fields': {'test_model': ['v1']},
+            'model': 'test_app.testmodelinlinebynaturalkey',
+            'pk': 1
+        }])
+        self.assertEqual(Version.objects.get_for_object(obj).get().field_dict, {
+            'test_model_id': 1,
+            'id': 1,
+        })