Logging support

apps/logs/models.py

@@ -0,0 +1,63 @@
+# Copyright (C) 2018-2020 by BDE ENS Paris-Saclay
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+from django.utils.translation import gettext_lazy as _
+from django.conf import settings
+from django.core.exceptions import ValidationError
+from django.db import models
+
+
+class Changelog(models.Model):
+    """
+    Store each modification on the database (except sessions and logging),
+    including creating, editing and deleting models.
+    """
+
+    user = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        on_delete=models.PROTECT,
+        null=True,
+        verbose_name=_('user'),
+    )
+
+    model = models.CharField(
+        max_length=255,
+        null=False,
+        blank=False,
+        verbose_name=_('model'),
+    )
+
+    instance_pk = models.CharField(
+        max_length=255,
+        null=False,
+        blank=False,
+        verbose_name=_('identifier'),
+    )
+
+    previous = models.TextField(
+        null=True,
+        verbose_name=_('previous data'),
+    )
+
+    data = models.TextField(
+        null=True,
+        verbose_name=_('new data'),
+    )
+
+    action = models.CharField(  # create, edit or delete
+        max_length=16,
+        null=False,
+        blank=False,
+        verbose_name=_('action'),
+    )
+
+    timestamp = models.DateTimeField(
+        null=False,
+        blank=False,
+        auto_now_add=True,
+        name='timestamp',
+        verbose_name=_('timestamp'),
+    )
+
+    def delete(self, using=None, keep_parents=False):
+        raise ValidationError(_("Logs cannot be destroyed."))