Implemented new object change logging to replace UserActions

netbox/extras/middleware.py

@@ -0,0 +1,63 @@
+from __future__ import unicode_literals
+
+import json
+
+from django.core.serializers import serialize
+from django.db.models.signals import post_delete, post_save
+from django.utils.functional import curry, SimpleLazyObject
+
+from utilities.models import ChangeLoggedModel
+from .constants import OBJECTCHANGE_ACTION_CREATE, OBJECTCHANGE_ACTION_DELETE, OBJECTCHANGE_ACTION_UPDATE
+from .models import ObjectChange
+
+
+def record_object_change(user, instance, **kwargs):
+    """
+    Create an ObjectChange in response to an object being created or deleted.
+    """
+    if not isinstance(instance, ChangeLoggedModel):
+        return
+
+    # Determine what action is being performed. The post_save signal sends a `created` boolean, whereas post_delete
+    # does not.
+    if 'created' in kwargs:
+        action = OBJECTCHANGE_ACTION_CREATE if kwargs['created'] else OBJECTCHANGE_ACTION_UPDATE
+    else:
+        action = OBJECTCHANGE_ACTION_DELETE
+
+    # Serialize the object using Django's built-in JSON serializer, then extract only the `fields` dict.
+    json_str = serialize('json', [instance])
+    object_data = json.loads(json_str)[0]['fields']
+
+    ObjectChange(
+        user=user,
+        changed_object=instance,
+        action=action,
+        object_data=object_data
+    ).save()
+
+
+class ChangeLoggingMiddleware(object):
+
+    def __init__(self, get_response):
+        self.get_response = get_response
+
+    def __call__(self, request):
+
+        def get_user(request):
+            return request.user
+
+        # DRF employs a separate authentication mechanism outside Django's normal request/response cycle, so calling
+        # request.user in middleware will always return AnonymousUser for API requests. To work around this, we point
+        # to a lazy object that doesn't resolve the user until after DRF's authentication has been called. For more
+        # detail, see https://stackoverflow.com/questions/26240832/
+        user = SimpleLazyObject(lambda: get_user(request))
+
+        # Django doesn't provide any request context with the post_save/post_delete signals, so we curry
+        # record_object_change() to include the user associated with the current request.
+        _record_object_change = curry(record_object_change, user)
+
+        post_save.connect(_record_object_change)
+        post_delete.connect(_record_object_change)
+
+        return self.get_response(request)