Better handle transactions in pre-save

easyaudit/signals/model_signals.py

@@ -6,6 +6,7 @@
 from django.contrib.auth.models import AnonymousUser
 from django.contrib.contenttypes.models import ContentType
 from django.core import serializers
+from django.core.exceptions import ObjectDoesNotExist
 from django.db import transaction
 from django.db.models import signals
 from django.utils import timezone
@@ -47,7 +48,7 @@ def should_audit(instance):
 
 # signals
 def pre_save(sender, instance, raw, using, update_fields, **kwargs):
-    """https://docs.djangoproject.com/es/1.10/ref/signals/#post-save"""
+    """https://docs.djangoproject.com/en/3.0/ref/signals/#pre-save"""
     if raw:
         # Return if loading Fixtures
         return
@@ -65,7 +66,13 @@ def pre_save(sender, instance, raw, using, update_fields, **kwargs):
             if instance.pk is None:
                 created = True
             else:
-                created = False
+                try:
+                    old_model = sender.objects.get(pk=instance.pk)
+                    created = False
+                except ObjectDoesNotExist:
+                    # This can happen when a model is saved as part of a Transaction. It then has
+                    # a pk set but is actually created.
+                    created = True
 
             # created or updated?
             if not created:
@@ -127,7 +134,7 @@ def crud_flow():
 
 
 def post_save(sender, instance, created, raw, using, update_fields, **kwargs):
-    """https://docs.djangoproject.com/es/1.10/ref/signals/#post-save"""
+    """https://docs.djangoproject.com/en/3.0/ref/signals/#post-save"""
     if raw:
         # Return if loading Fixtures
         return

easyaudit/tests/test_app/models.py

@@ -1,4 +1,4 @@
-from django.db import models
+from django.db import models, transaction
 
 
 class TestModel(models.Model):
@@ -13,3 +13,15 @@ class TestForeignKey(models.Model):
 class TestM2M(models.Model):
     name = models.CharField(max_length=50)
     test_m2m = models.ManyToManyField(TestModel)
+
+
+@transaction.atomic
+def create_in_transaction():
+    m = TestModel.objects.create(name='Transaction')
+    fk = TestForeignKey.objects.create(name='TransactionFK', test_fk=m)
+    m2m = TestM2M(name='TrasactionM2M')
+    m2m.save()
+    m2m.test_m2m.add(m)
+    m2m.save()
+
+    return m

easyaudit/tests/test_app/tests.py

@@ -10,9 +10,10 @@
 from django.contrib.auth.models import User
 from django.contrib.contenttypes.models import ContentType
 import bs4
-from test_app.models import TestModel, TestForeignKey, TestM2M
+from test_app.models import TestModel, TestForeignKey, TestM2M, create_in_transaction
 from easyaudit.models import CRUDEvent
 from easyaudit.middleware.easyaudit import set_current_user, clear_request
+from easyaudit.signals import model_signals
 
 
 TEST_USER_EMAIL = 'joe@example.com'
@@ -84,6 +85,11 @@ def test_fake_update(self):
         obj.save()
         self.assertEqual(2, crud_event_qs.count())
 
+    def test_transactions(self):
+        obj = create_in_transaction()
+        crud_event_qs = CRUDEvent.objects.filter(object_id=obj.id, content_type=ContentType.objects.get_for_model(obj))
+        self.assertTrue(2, crud_event_qs.count())
+
 
 @override_settings(TEST=True)
 class TestMiddleware(TestCase):
@@ -185,3 +191,16 @@ def test_request_event_admin_no_users(self):
         response = self.client.get(reverse('admin:easyaudit_requestevent_changelist'))
         self.assertEqual(200, response.status_code)
         filters = self._list_filters(response.content)
+
+
+@override_settings(TEST=True)
+class TestPreSave(TestCase):
+    def test_new_model_with_id(self):
+        obj = TestModel(name='Bob')
+        obj.pk = 123
+        model_signals.pre_save(TestModel, obj, None, 'default', None)
+
+        # No event must be registered in pre-save as this model isn't created yet.
+        crud_event_qs = CRUDEvent.objects.filter(object_id=obj.id, content_type=ContentType.objects.get_for_model(obj))
+        self.assertEqual(crud_event_qs.count(), 0)
+