From 15704762ed6ca8ba779001e4248062f466775e8f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Laura=20Kl=C3=BCnder?= <laura@codingcatgirl.de>
Date: Thu, 29 Jun 2017 14:51:46 +0200
Subject: [PATCH] add ChangedObject.stale

---
 .../migrations/0006_auto_20170629_1222.py     | 29 ++++++++++++++++++
 src/c3nav/editor/models/changedobject.py      | 30 ++++++++++++-------
 src/c3nav/editor/models/changeset.py          |  5 ++--
 3 files changed, 50 insertions(+), 14 deletions(-)
 create mode 100644 src/c3nav/editor/migrations/0006_auto_20170629_1222.py

diff --git a/src/c3nav/editor/migrations/0006_auto_20170629_1222.py b/src/c3nav/editor/migrations/0006_auto_20170629_1222.py
new file mode 100644
index 00000000..5faf9268
--- /dev/null
+++ b/src/c3nav/editor/migrations/0006_auto_20170629_1222.py
@@ -0,0 +1,29 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.2 on 2017-06-29 12:22
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('editor', '0005_auto_20170627_0027'),
+    ]
+
+    operations = [
+        migrations.AlterModelOptions(
+            name='changedobject',
+            options={'base_manager_name': 'objects', 'ordering': ['created', 'pk'], 'verbose_name': 'Changed object', 'verbose_name_plural': 'Changed objects'},
+        ),
+        migrations.AddField(
+            model_name='changedobject',
+            name='stale',
+            field=models.BooleanField(default=False, verbose_name='stale'),
+        ),
+        migrations.AlterField(
+            model_name='changedobject',
+            name='deleted',
+            field=models.BooleanField(default=False, verbose_name='object was deleted'),
+        ),
+    ]
diff --git a/src/c3nav/editor/models/changedobject.py b/src/c3nav/editor/models/changedobject.py
index 6347ab49..4e1eac5b 100644
--- a/src/c3nav/editor/models/changedobject.py
+++ b/src/c3nav/editor/models/changedobject.py
@@ -25,7 +25,8 @@ class ChangedObject(models.Model):
     updated_fields = JSONField(default={}, verbose_name=_('updated fields'))
     m2m_added = JSONField(default={}, verbose_name=_('added m2m values'))
     m2m_removed = JSONField(default={}, verbose_name=_('removed m2m values'))
-    deleted = models.BooleanField(default=False, verbose_name=_('new field value'))
+    deleted = models.BooleanField(default=False, verbose_name=_('object was deleted'))
+    stale = models.BooleanField(default=False, verbose_name=_('stale'))
 
     objects = ChangedObjectManager()
 
@@ -107,7 +108,10 @@ class ChangedObject(models.Model):
         model = self.model_class
         pk = self.obj_pk
 
-        self.changeset.changed_objects.setdefault(model, {})[pk] = self
+        if not self.stale:
+            self.changeset.changed_objects.setdefault(model, {})[pk] = self
+        else:
+            self.changeset.changed_objects.get(model, {}).pop(pk, None)
 
         if self.is_created:
             if not self.deleted:
@@ -257,19 +261,23 @@ class ChangedObject(models.Model):
     def save(self, *args, **kwargs):
         if self.changeset.proposed is not None or self.changeset.applied is not None:
             raise TypeError('can not add change object to uneditable changeset.')
-        if not self.does_something:
-            if self.pk is not None:
-                self.delete()
-            return False
-        if self.changeset.pk is None:
-            self.changeset.save()
-            self.changeset = self.changeset
         self.m2m_added = {name: tuple(values) for name, values in self._m2m_added_cache.items()}
         self.m2m_removed = {name: tuple(values) for name, values in self._m2m_removed_cache.items()}
-        super().save(*args, **kwargs)
+        if not self.does_something:
+            self.stale = True
+        if not self.stale:
+            if self.changeset.pk is None:
+                self.changeset.save()
+                self.changeset = self.changeset
+        else:
+            self.existing_object_pk = None
         if not self.changeset.fill_changes_cache():
             self.update_changeset_cache()
-        return True
+        if not self.stale or self.pk is not None:
+            super().save(*args, **kwargs)
+
+    def delete(self, **kwargs):
+        raise TypeError('changed objects can not be deleted directly.')
 
     def __repr__(self):
         return '<ChangedObject #%s on ChangeSet #%s>' % (str(self.pk), str(self.changeset_id))
diff --git a/src/c3nav/editor/models/changeset.py b/src/c3nav/editor/models/changeset.py
index 1bd4d1fb..78f3014a 100644
--- a/src/c3nav/editor/models/changeset.py
+++ b/src/c3nav/editor/models/changeset.py
@@ -1,6 +1,5 @@
 from collections import OrderedDict
 from itertools import chain
-from operator import attrgetter
 
 from django.apps import apps
 from django.conf import settings
@@ -120,7 +119,7 @@ class ChangeSet(models.Model):
         return self.wrap_model(instance.__class__).create_wrapped_model_class()(self, instance)
 
     def relevant_changed_objects(self):
-        return self.changed_objects_set.exclude(existing_object_pk__isnull=True, deleted=True)
+        return self.changed_objects_set.exclude(stale=True).exclude(existing_object_pk__isnull=True, deleted=True)
 
     def fill_changes_cache(self, include_deleted_created=False):
         """
@@ -139,7 +138,7 @@ class ChangeSet(models.Model):
             return False
 
         if include_deleted_created:
-            qs = self.changed_objects_set.all()
+            qs = self.changed_objects_set.exclude(stale=True)
         else:
             qs = self.relevant_changed_objects()