From 1023c6c5022f364659082da114df2702b4ea3853 Mon Sep 17 00:00:00 2001
From: Yohann D'ANELLO <yohann.danello@gmail.com>
Date: Sun, 6 Sep 2020 20:18:59 +0200
Subject: [PATCH] Use pre_delete signal insted of Model.delete() to prevent
 note balance issues when deleting a transaction (don't do it) in Django Admin

---
 apps/note/apps.py                | 7 ++++++-
 apps/note/models/transactions.py | 8 --------
 apps/note/signals.py             | 8 ++++++++
 3 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/apps/note/apps.py b/apps/note/apps.py
index 4881e3b9..b3dc5a0f 100644
--- a/apps/note/apps.py
+++ b/apps/note/apps.py
@@ -3,7 +3,7 @@
 
 from django.apps import AppConfig
 from django.conf import settings
-from django.db.models.signals import post_save
+from django.db.models.signals import post_save, pre_delete
 from django.utils.translation import gettext_lazy as _
 
 from . import signals
@@ -25,3 +25,8 @@ class NoteConfig(AppConfig):
             signals.save_club_note,
             sender='member.Club',
         )
+
+        pre_delete.connect(
+            signals.delete_transaction,
+            sender='note.transaction',
+        )
diff --git a/apps/note/models/transactions.py b/apps/note/models/transactions.py
index a4f220bd..d10bf3a6 100644
--- a/apps/note/models/transactions.py
+++ b/apps/note/models/transactions.py
@@ -242,14 +242,6 @@ class Transaction(PolymorphicModel):
         self.destination._force_save = True
         self.destination.save()
 
-    def delete(self, **kwargs):
-        """
-        Whenever we want to delete a transaction (caution with this), we ensure the transaction is invalid first.
-        """
-        self.valid = False
-        self.save(**kwargs)
-        super().delete(**kwargs)
-
     @property
     def total(self):
         return self.amount * self.quantity
diff --git a/apps/note/signals.py b/apps/note/signals.py
index 06bb480b..51ed92d8 100644
--- a/apps/note/signals.py
+++ b/apps/note/signals.py
@@ -24,3 +24,11 @@ def save_club_note(instance, raw, **_kwargs):
     from .models import NoteClub
     NoteClub.objects.get_or_create(club=instance)
     instance.note.save()
+
+
+def delete_transaction(instance, **_kwargs):
+    """
+    Whenever we want to delete a transaction (caution with this), we ensure the transaction is invalid first.
+    """
+    instance.valid = False
+    instance.save()