fix: only fire the post_log signal when the log is created or when there is an error (#561)

CHANGELOG.md

@@ -7,6 +7,7 @@
 #### Improvements
 
 #### Fixes
+* fix: only fire the `post_log` signal when the log is created or when there is an error in the process.
 
 ## 3.0.0-beta.1
 

auditlog/receivers.py

@@ -105,6 +105,8 @@ def _create_log_entry(
         action=action,
     )
     error = None
+    log_created = False
+    changes = None
     try:
         changes = model_instance_diff(
             diff_old, diff_new, fields_to_check=fields_to_check
@@ -117,17 +119,21 @@ def _create_log_entry(
                 changes=changes,
                 force_log=force_log,
             )
+            log_created = True
     except BaseException as e:
         error = e
     finally:
-        post_log.send(
-            sender,
-            instance=instance,
-            instance_old=diff_old,
-            action=action,
-            error=error,
-            pre_log_results=pre_log_results,
-        )
+        if log_created or error:
+            post_log.send(
+                sender,
+                instance=instance,
+                instance_old=diff_old,
+                action=action,
+                error=error,
+                pre_log_results=pre_log_results,
+                changes=changes,
+                log_created=log_created,
+            )
         if error:
             raise error
 

auditlog/signals.py

@@ -27,6 +27,8 @@ post_log = django.dispatch.Signal()
 """
 Whenever an audit log entry is written, this signal
 is sent after writing the log.
+This signal is also fired when there is an error in creating the log.
+
 Keyword arguments sent with this signal:
 
 :param class sender:
@@ -39,6 +41,15 @@ Keyword arguments sent with this signal:
     The action on the model resulting in an
     audit log entry. Type: :class:`auditlog.models.LogEntry.Action`
 
+:param Optional[dict] changes:
+    The changes that were logged. If there was en error while determining the changes,
+    this will be None. In some cases, such as when logging access to the instance,
+    the changes will be an empty dict.
+
+:param bool log_created:
+    Was the log actually created?
+    This could be false if there was an error in creating the log.
+
 :param Optional[Exception] error:
     The error, if one occurred while saving the audit log entry. ``None``,
     otherwise