Fixes #14329: Improve diffs for custom fields

netbox/extras/views.py

@@ -22,7 +22,7 @@ from utilities.htmx import is_htmx
 from utilities.paginator import EnhancedPaginator, get_paginate_count
 from utilities.rqworker import get_workers_for_queue
 from utilities.templatetags.builtins.filters import render_markdown
-from utilities.utils import copy_safe_request, count_related, get_viewname, normalize_querydict, shallow_compare_dict
+from utilities.utils import copy_safe_request, count_related, deep_compare_dict, get_viewname, normalize_querydict
 from utilities.views import ContentTypePermissionRequiredMixin, register_model_view
 from . import filtersets, forms, tables
 from .forms.reports import ReportForm
@@ -719,14 +719,7 @@ class ObjectChangeView(generic.ObjectView):
             prechange_data = instance.prechange_data
 
         if prechange_data and instance.postchange_data:
-            diff_added = shallow_compare_dict(
-                prechange_data or dict(),
-                instance.postchange_data or dict(),
-                exclude=['last_updated'],
-            )
-            diff_removed = {
-                x: prechange_data.get(x) for x in diff_added
-            } if prechange_data else {}
+            diff_added, diff_removed = deep_compare_dict(prechange_data, instance.postchange_data, exclude=('last_updated'))
         else:
             diff_added = None
             diff_removed = None

netbox/utilities/utils.py

@@ -395,20 +395,34 @@ def prepare_cloned_fields(instance):
     return QueryDict(urlencode(params), mutable=True)
 
 
-def shallow_compare_dict(source_dict, destination_dict, exclude=tuple()):
+def deep_compare_dict(old, new, exclude=tuple()):
     """
-    Return a new dictionary of the different keys. The values of `destination_dict` are returned. Only the equality of
-    the first layer of keys/values is checked. `exclude` is a list or tuple of keys to be ignored.
+    Return a tuple of two dictionaries `(removed_diffs, added_diffs)` in a format
+    that is compatible with the requirements of `ObjectChangeView`.
+    `exclude` is a list or tuple of keys to be ignored.
     """
-    difference = {}
+    added_diffs = {}
+    removed_diffs = {}
 
-    for key, value in destination_dict.items():
+    for key in old:
         if key in exclude:
             continue
-        if source_dict.get(key) != value:
-            difference[key] = value
 
-    return difference
+        old_data = old[key]
+        new_data = new[key]
+
+        if old_data != new_data:
+            if isinstance(old_data, dict) and isinstance(new_data, dict):
+                (sub_added, sub_removed) = deep_compare_dict(old_data, new_data, exclude=exclude)
+                if len(sub_removed) > 0:
+                    removed_diffs[key] = sub_removed
+                if len(sub_added) > 0:
+                    added_diffs[key] = sub_added
+            else:
+                removed_diffs[key] = old_data
+                added_diffs[key] = new_data
+
+    return added_diffs, removed_diffs
 
 
 def flatten_dict(d, prefix='', separator='.'):