Merge pull request #92 from AbdullahKady/support-update_fields

Support Django's `update_fields` in save method

Author: rsinger86

django_lifecycle/mixins.py

@@ -126,26 +126,26 @@ def save(self, *args, **kwargs):
         is_new = self._state.adding
 
         if is_new:
-            self._run_hooked_methods(BEFORE_CREATE)
+            self._run_hooked_methods(BEFORE_CREATE, **kwargs)
         else:
-            self._run_hooked_methods(BEFORE_UPDATE)
+            self._run_hooked_methods(BEFORE_UPDATE, **kwargs)
 
-        self._run_hooked_methods(BEFORE_SAVE)
+        self._run_hooked_methods(BEFORE_SAVE, **kwargs)
         save(*args, **kwargs)
-        self._run_hooked_methods(AFTER_SAVE)
+        self._run_hooked_methods(AFTER_SAVE, **kwargs)
 
         if is_new:
-            self._run_hooked_methods(AFTER_CREATE)
+            self._run_hooked_methods(AFTER_CREATE, **kwargs)
         else:
-            self._run_hooked_methods(AFTER_UPDATE)
+            self._run_hooked_methods(AFTER_UPDATE, **kwargs)
 
         self._initial_state = self._snapshot_state()
 
     @transaction.atomic
     def delete(self, *args, **kwargs):
-        self._run_hooked_methods(BEFORE_DELETE)
+        self._run_hooked_methods(BEFORE_DELETE, **kwargs)
         value = super().delete(*args, **kwargs)
-        self._run_hooked_methods(AFTER_DELETE)
+        self._run_hooked_methods(AFTER_DELETE, **kwargs)
         return value
 
     @classmethod
@@ -188,7 +188,7 @@ def _watched_fk_model_fields(cls) -> List[str]:
     def _watched_fk_models(cls) -> List[str]:
         return [_.split(".")[0] for _ in cls._watched_fk_model_fields()]
 
-    def _run_hooked_methods(self, hook: str) -> List[str]:
+    def _run_hooked_methods(self, hook: str, **kwargs) -> List[str]:
         """
         Iterate through decorated methods to find those that should be
         triggered by the current hook. If conditions exist, check them before
@@ -204,14 +204,24 @@ def _run_hooked_methods(self, hook: str) -> List[str]:
                 when_field = callback_specs.get("when")
                 when_any_field = callback_specs.get("when_any")
 
+                # None is explicit instead of an empty list; since Django aborts the save with an empty list
+                update_fields = kwargs.get("update_fields", None)
+                update_fields_exist = update_fields is not None
+
                 if when_field:
+                    if update_fields_exist and when_field not in update_fields:
+                        continue
                     if not self._check_callback_conditions(when_field, callback_specs):
                         continue
                 elif when_any_field:
+                    filtered_when_any_fields = when_any_field
+                    if update_fields_exist:
+                        filtered_when_any_fields = list(set(update_fields) & set(when_any_field))  # Intersected.
+
                     if not any(
                         [
                             self._check_callback_conditions(field_name, callback_specs)
-                            for field_name in when_any_field
+                            for field_name in filtered_when_any_fields
                         ]
                     ):
                         continue

tests/testapp/tests/test_mixin.py

@@ -316,6 +316,24 @@ def test_changes_to_condition_should_pass(self):
             user_account.last_name = "Flanders"
             user_account.save()
 
+    def test_changes_to_condition_included_in_update_fields_should_fire_hook(self):
+        user_account = UserAccount.objects.create(**self.stub_data)
+        user_account.first_name = "Flanders"
+        user_account.last_name = "Flanders"
+        with self.assertRaises(CannotRename, msg="Oh, not Flanders. Anybody but Flanders."):
+            user_account.last_name = "Flanders"
+            user_account.save(update_fields=["last_name"])
+
+    def test_changes_to_condition_not_included_in_update_fields_should_not_fire_hook(self):
+        user_account = UserAccount.objects.create(**self.stub_data)
+        user_account.first_name = "Flanders"
+        user_account.last_name = "Flanders"
+        user_account.save(update_fields=["first_name"])  # `CannotRename` exception is not raised
+
+        user_account.refresh_from_db()
+        self.assertEqual(user_account.first_name, "Flanders")
+        self.assertNotEqual(user_account.last_name, "Flanders")
+
     def test_changes_to_condition_should_not_pass(self):
         data = self.stub_data
         data["first_name"] = "Marge"

tests/testapp/tests/test_user_account.py

@@ -117,6 +117,43 @@ def test_email_user_about_name_change(self):
             mail.outbox[0].body, "You changed your first name or your last name"
         )
 
+    def test_does_not_email_user_about_name_change_when_name_excluded_from_update_fields(self):
+        account = UserAccount.objects.create(**self.stub_data)
+        mail.outbox = []
+        account.first_name = "Homer the Great"
+        account.password = "New password!"
+
+        old_password_updated_at = account.password_updated_at
+        account.save(update_fields=["password"])
+        self.assertEqual(len(mail.outbox), 0)  # `first_name` change was skipped (as a hook).
+        self.assertNotEqual(account.password_updated_at, old_password_updated_at)  # Ensure the other hook is fired.
+
+    def test_emails_user_about_name_change_when_one_field_from_update_fields_intersects_with_condition(self):
+        account = UserAccount.objects.create(**self.stub_data)
+        mail.outbox = []
+        account.first_name = "Homer the Great"
+        account.password = "New password!"
+
+        old_password_updated_at = account.password_updated_at
+        account.save(update_fields=["first_name", "password"])
+        self.assertEqual(
+            mail.outbox[0].body, "You changed your first name or your last name"
+        )
+        self.assertNotEqual(account.password_updated_at, old_password_updated_at)  # Both hooks fired.
+
+    def test_empty_update_fields_does_not_fire_any_hooks(self):
+        # In Django, an empty list supplied to `update_fields` means not updating any field.
+        account = UserAccount.objects.create(**self.stub_data)
+        mail.outbox = []
+        account.first_name = "Flanders"
+        account.password = "new pass"
+
+        old_password_updated_at = account.password_updated_at
+        account.save(update_fields=[])
+        # Did not raise, so last name hook didn't fire.
+        self.assertEqual(len(mail.outbox), 0)
+        self.assertEqual(account.password_updated_at, old_password_updated_at)  # Password hook didn't fire either.
+
     def test_skip_hooks(self):
         """
         Hooked method that auto-lowercases email should be skipped.