Add exclude_history_fields field for binder history

Author: coenvdgrinten

binder/models.py

@@ -608,6 +608,7 @@ def binder_serialize_m2m_field(self, field):
 
 	class Binder:
 		history = False
+		exclude_history_fields: list[str] = []
 
 	class Meta:
 		abstract = True
@@ -683,13 +684,22 @@ def field_needs_nullability_check(field):
 def history_obj_post_init(sender, instance, **kwargs):
 	instance._history = instance.binder_concrete_fields_as_dict(skip_deferred_fields=True)
 
+	excluded_fields = getattr(sender.Binder, 'exclude_history_fields', [])
+	for field_name in excluded_fields:
+		instance._history.pop(field_name, None)
+
 	if not instance.pk:
 		instance._history = {k: history.NewInstanceField for k in instance._history}
 
 
 
 def history_obj_post_save(sender, instance, **kwargs):
+	excluded_fields = getattr(sender.Binder, 'exclude_history_fields', [])
+
 	for field_name, new_value in instance.binder_concrete_fields_as_dict().items():
+		if field_name in excluded_fields:
+			continue
+
 		try:
 			old_value = instance._history[field_name]
 			if old_value != new_value:

docs/models.md

@@ -98,6 +98,20 @@ class Animal(BinderModel):
 		history = True
 ```
 
+You can also exclude specific fields from history tracking by setting `exclude_history_fields`:
+
+```python
+from binder.models import BinderModel
+
+class Animal(BinderModel):
+	name = models.TextField()
+	secret_notes = models.TextField()  # This field won't be tracked
+	
+	class Binder:
+		history = True
+		exclude_history_fields = ['secret_notes']
+```
+
 Saving the model will result in one changeset. With a changeset, the user that changed it and datetime is saved.
 
 A changeset contains changes for each field that has been changed to a new value. For each change, you can see the old value and the new value.

tests/test_history.py

@@ -7,7 +7,7 @@
 from binder import history
 from binder.history import Change, Changeset
 
-from .testapp.models import Animal, Caretaker, ContactPerson
+from .testapp.models import Animal, Caretaker, ContactPerson, Zoo
 
 
 class HistoryTest(TestCase):
@@ -346,3 +346,65 @@ class TestException(Exception):
 		# Aborted, so still no history
 		self.assertEqual(0, Changeset.objects.count())
 		self.assertEqual(0, Change.objects.count())
+
+	def test_exclude_history_fields_prevents_tracking(self):
+		"""Test that fields listed in exclude_history_fields are not tracked in history"""
+		original_exclude_fields = getattr(Animal.Binder, 'exclude_history_fields', [])
+		Animal.Binder.exclude_history_fields = ['name']
+		
+		try:
+			model_data = {
+				'name': 'Test Animal',
+			}
+			response = self.client.post('/animal/', data=json.dumps(model_data), content_type='application/json')
+			self.assertEqual(response.status_code, 200)
+			animal_id = json.loads(response.content)['id']
+			
+			# Check that we have a changeset for the creation
+			self.assertEqual(1, Changeset.objects.count())
+			cs = Changeset.objects.get()
+			
+			# Check that changes exist for normal fields but not for excluded fields
+			changes = Change.objects.filter(changeset=cs)
+			field_names = [change.field for change in changes]
+			
+			# The 'name' field should be excluded from history
+			self.assertNotIn('name', field_names)
+			# Other fields should still be tracked
+			self.assertIn('id', field_names)
+			self.assertIn('deleted', field_names)
+			
+			model_data = {
+				'name': 'Updated Animal Name',
+			}
+			response = self.client.patch(f'/animal/{animal_id}/', data=json.dumps(model_data), content_type='application/json')
+			self.assertEqual(response.status_code, 200)
+			
+			# Should still only have 1 changeset (no new one created for excluded field)
+			self.assertEqual(1, Changeset.objects.count())
+			
+			# Now update both an excluded field AND a non-excluded field
+			zoo = Zoo.objects.create(name='Test Zoo')
+			model_data = {
+				'name': 'Another Name Update',  # excluded field
+				'zoo': zoo.id,  # non-excluded field
+			}
+			response = self.client.patch(f'/animal/{animal_id}/', data=json.dumps(model_data), content_type='application/json')
+			self.assertEqual(response.status_code, 200)
+			
+			# Now we should have 2 changesets (original creation + this mixed update)
+			self.assertEqual(2, Changeset.objects.count())
+			
+			# Check the latest changeset (for the mixed update)
+			latest_cs = Changeset.objects.order_by('-id').first()
+			latest_changes = Change.objects.filter(changeset=latest_cs)
+			latest_field_names = [change.field for change in latest_changes]
+			
+			# Only the zoo field should be recorded, not the name
+			self.assertEqual(1, len(latest_field_names))
+			self.assertIn('zoo', latest_field_names)
+			self.assertNotIn('name', latest_field_names)
+			
+		finally:
+			# Restore original exclude_history_fields setting
+			Animal.Binder.exclude_history_fields = original_exclude_fields