First things to implement a event change log

dav_events/migrations/0034_eventchange.py

@@ -0,0 +1,35 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.29 on 2020-09-29 10:11
+from __future__ import unicode_literals
+
+import dav_events.models.eventchange
+import dav_events.roles
+from django.conf import settings
+from django.db import migrations, models
+import django.db.models.deletion
+import django.utils.timezone
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+        ('dav_events', '0033_auto_20200925_1543'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='EventChange',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('timestamp', models.DateTimeField(default=django.utils.timezone.now)),
+                ('operation', models.CharField(choices=[('update', 'update')], max_length=20)),
+                ('content', models.TextField()),
+                ('event', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='changes', to='dav_events.Event')),
+                ('user', models.ForeignKey(default=dav_events.models.eventchange.get_system_user_id, on_delete=models.SET(dav_events.roles.get_ghost_user), related_name='+', to=settings.AUTH_USER_MODEL)),
+            ],
+            options={
+                'ordering': ['event', 'timestamp'],
+            },
+        ),
+    ]

dav_events/models/__init__.py

@@ -1,5 +1,6 @@
 from ..roles import get_system_user, get_ghost_user
 from .event import Event
+from .eventchange import EventChange
 from .eventflag import EventFlag
 from .eventstatus import EventStatus
 from .oneclickaction import OneClickAction

dav_events/models/event.py

@@ -2,6 +2,7 @@
 from __future__ import unicode_literals
 import datetime
 import difflib
+import json
 import logging
 import os
 import re
@@ -16,12 +17,12 @@ from django.utils.encoding import python_2_unicode_compatible
 from django.utils.translation import get_language, ugettext_lazy as _
 from django_countries.fields import CountryField
 
-from . import get_ghost_user
 from .. import choices
 from .. import config
 from .. import signals
 from ..workflow import DefaultWorkflow
-
+from . import get_ghost_user
+from .eventchange import EventChange
 
 logger = logging.getLogger(__name__)
 
@@ -292,9 +293,8 @@ class Event(models.Model):
                 logger.warning('Event is not created by its owner (Current user: %s, Owner: %s)!', self.editor, owner)
             self.owner = owner
             creating = True
-        elif not implicit_update:
+        else:
             original = Event.objects.get(id=self.id)
-            original_text = original.render_as_text(show_internal_fields=True)
 
         if not self.editor or not self.editor.is_authenticated:
             self.editor = self.owner
@@ -305,13 +305,40 @@ class Event(models.Model):
             logger.info('Event created: %s', self)
             signals.event_created.send(sender=self.__class__, event=self)
             self.workflow.update_status('draft', self.editor)
-        elif not implicit_update:
-            modified_text = self.render_as_text(show_internal_fields=True)
-            o_lines = original_text.split('\n')
-            m_lines = modified_text.split('\n')
-            diff_lines = list(difflib.unified_diff(o_lines, m_lines, n=len(m_lines), lineterm=''))
+        else:
+            change = EventChange(event=self, user=self.editor, operation='update', content=self.diff(original))
+            change.save()
+            if not implicit_update:
                 logger.info('Event updated: %s', self)
-            signals.event_updated.send(sender=self.__class__, event=self, diff=diff_lines, user=self.editor)
+                signals.event_updated.send(sender=self.__class__, event=self, diff=self.diff(original, fmt='human_readable'), user=self.editor)
+
+    def diff(self, event, fmt='json'):
+        if fmt == 'human_readable':
+            from_text = event.render_as_text(show_internal_fields=True)
+            to_text = self.render_as_text(show_internal_fields=True)
+            from_lines = from_text.split('\n')
+            to_lines = to_text.split('\n')
+            diff_lines = list(difflib.unified_diff(from_lines, to_lines, n=len(from_lines), lineterm=''))
+            diff_text = '\n'.join(diff_lines[3:])
+        elif fmt == 'json':
+            fields = self._meta.get_fields()
+            changes = []
+            for field in fields:
+                field_name = field.name
+                from_value = getattr(event, field_name)
+                to_value = getattr(self, field_name)
+                if from_value != to_value:
+                    change = {
+                        'field': field_name,
+                        'refer': str(from_value),
+                        'current': str(to_value),
+                    }
+                    changes.append(change)
+            diff_text = json.dumps(changes)
+        else:
+            raise ValueError("Event.diff(): Unsupported format: {}".format(fmt))
+
+        return diff_text
 
     def is_deadline_expired(self):
         today = datetime.date.today()

dav_events/models/eventchange.py

@@ -0,0 +1,36 @@
+from __future__ import unicode_literals
+from django.conf import settings
+from django.db import models
+from django.utils import timezone
+from django.utils.encoding import python_2_unicode_compatible
+
+from . import get_ghost_user, get_system_user
+
+CHANGE_OPERATIONS = (
+    ('update', 'update'),
+)
+
+
+def get_system_user_id():
+    return get_system_user().id
+
+
+@python_2_unicode_compatible
+class EventChange(models.Model):
+    event = models.ForeignKey('dav_events.Event', related_name='changes')
+    timestamp = models.DateTimeField(default=timezone.now)
+    user = models.ForeignKey(settings.AUTH_USER_MODEL,
+                             default=get_system_user_id,
+                             on_delete=models.SET(get_ghost_user),
+                             related_name='+')
+
+    operation = models.CharField(max_length=20, choices=CHANGE_OPERATIONS)
+    content = models.TextField()
+
+    class Meta:
+        ordering = ['event', 'timestamp']
+
+    def __str__(self):
+        s = '{timestamp} - {user} - {operation}'
+        return s.format(operation=self.operation, timestamp=self.timestamp.strftime('%d.%m.%Y %H:%M:%S %Z'),
+                        user=self.user)

dav_events/tests/test_models.py

@@ -0,0 +1,54 @@
+from __future__ import unicode_literals
+import datetime
+import json
+from django.test import TestCase
+
+from .generic import EventMixin
+
+TEST_EVENT_DATA = {
+    'title': 'Täst',
+    'description': 'Teßt',
+    'mode': 'joint',
+    'sport': 'W',
+    'level': 'beginner',
+    'first_day': datetime.date(2019, 3, 1),
+    'country': 'DE',
+    'trainer_firstname': 'Übungsleiter',
+    'trainer_familyname': 'Weißalles',
+    'trainer_email': 'trainer@localhost',
+}
+
+
+class EventsTestCase(EventMixin, TestCase):
+    def test_empty_changelog(self):
+        data = TEST_EVENT_DATA
+        event = self.create_event_by_model(data)
+        event.sport = 'M'
+        self.assertFalse(event.changes.exists())
+
+    def test_changelog(self):
+        data = TEST_EVENT_DATA
+        event = self.create_event_by_model(data)
+
+        event.alt_first_day = event.first_day + datetime.timedelta(1)
+        event.sport = 'M'
+        event.ski_lift = True
+        event.save()
+
+        event.country = 'FR'
+        event.max_participants = 8
+        event.save()
+
+        changes = event.changes
+        self.assertEqual(changes.count(), 2)
+
+        subchanges = json.loads(changes.first().content)
+        self.assertEqual(len(subchanges), 3)
+        self.assertIn({'field': 'alt_first_day', 'refer': 'None', 'current': '2019-03-02'}, subchanges)
+        self.assertIn({'field': 'sport', 'refer': 'W', 'current': 'M'}, subchanges)
+        self.assertIn({'field': 'ski_lift', 'refer': 'False', 'current': 'True'}, subchanges)
+
+        subchanges = json.loads(changes.last().content)
+        self.assertEqual(len(subchanges), 2)
+        self.assertIn({'field': 'country', 'refer': 'DE', 'current': 'FR'}, subchanges)
+        self.assertIn({'field': 'max_participants', 'refer': '0', 'current': '8'}, subchanges)

dav_events/workflow.py

@@ -312,10 +312,9 @@ class BasicWorkflow(object):
         if not app_config.settings.enable_email_on_update:
             return
 
-        if len(diff) < 1:
+        if not diff:
             logger.debug('send_emails_on_update(): No diff data -> Skip sending mails.')
             return
-        diff_text = '\n'.join(diff[3:])
 
         # Who should be informed about the update?
         recipients = [event.owner]
@@ -329,7 +328,7 @@ class BasicWorkflow(object):
 
         for recipient in recipients:
             if recipient.email and recipient.email != updater.email:
-                email = emails.EventUpdatedMail(recipient=recipient, event=event, editor=updater, diff=diff_text)
+                email = emails.EventUpdatedMail(recipient=recipient, event=event, editor=updater, diff=diff)
                 email.send()
 
     def send_emails_on_status_update(self, flag):