Add a simple framework for event- and organizer-related settings

src/pretix/base/migrations/0009_eventsetting_organizersetting.py

@@ -0,0 +1,49 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import models, migrations
+import versions.models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0008_quota_locked'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='EventSetting',
+            fields=[
+                ('id', models.CharField(primary_key=True, serialize=False, max_length=36)),
+                ('identity', models.CharField(max_length=36)),
+                ('version_start_date', models.DateTimeField()),
+                ('version_end_date', models.DateTimeField(blank=True, default=None, null=True)),
+                ('version_birth_date', models.DateTimeField()),
+                ('key', models.CharField(max_length=255)),
+                ('value', models.TextField()),
+                ('event', versions.models.VersionedForeignKey(related_name='setting_objects', to='pretixbase.Event')),
+            ],
+            options={
+                'abstract': False,
+            },
+            bases=(models.Model,),
+        ),
+        migrations.CreateModel(
+            name='OrganizerSetting',
+            fields=[
+                ('id', models.CharField(primary_key=True, serialize=False, max_length=36)),
+                ('identity', models.CharField(max_length=36)),
+                ('version_start_date', models.DateTimeField()),
+                ('version_end_date', models.DateTimeField(blank=True, default=None, null=True)),
+                ('version_birth_date', models.DateTimeField()),
+                ('key', models.CharField(max_length=255)),
+                ('value', models.TextField()),
+                ('organizer', versions.models.VersionedForeignKey(related_name='setting_objects', to='pretixbase.Organizer')),
+            ],
+            options={
+                'abstract': False,
+            },
+            bases=(models.Model,),
+        ),
+    ]

src/pretix/base/models.py

@@ -7,6 +7,7 @@ from django.db import models
 from django.conf import settings
 from django.contrib.auth.models import AbstractBaseUser, BaseUserManager, PermissionsMixin
 from django.db.models import Q, Count
+from django.utils.functional import cached_property
 from django.utils.timezone import now
 from django.utils.translation import ugettext_lazy as _
 from django.template.defaultfilters import date as _date
@@ -227,6 +228,58 @@ class Organizer(Versionable):
     def __str__(self):
         return self.name
 
+    class OrganizerSettingsProxy:
+        """
+        This objects allows convenient access to settings stored in the
+        OrganizerSettings database model. It exposes all settings as properties
+        and it will do all the nasty defaults stuff for
+        you. It will return None for non-existing properties.
+        """
+
+        def __init__(self, organizer):
+            self._organizer = organizer
+            self._cached_obj = None
+
+        def _cache(self):
+            if self._cached_obj is None:
+                self._cached_obj = {}
+                for setting in self._organizer.setting_objects.current.all():
+                    self._cached_obj[setting.key] = setting
+            return self._cached_obj
+
+        def __getattr__(self, key):
+            if key in self._cache():
+                return self._cache()[key].value
+            if key in OrganizerSetting.DEFAULTS:
+                return OrganizerSetting.DEFAULTS[key]
+            return None
+
+        def __delattr__(self, key):
+            if key.startswith('_'):
+                return super().__delattr__(key)
+            if key in self._cache():
+                self._cache()[key].delete()
+                del self._cache()[key]
+
+        def __setattr__(self, key, value):
+            if key.startswith('_'):
+                return super().__setattr__(key, value)
+            if key in self._cache():
+                s = self._cache()[key]
+                s = s.clone()
+            else:
+                s = OrganizerSetting(organizer=self._organizer, key=key)
+            s.value = value
+            s.save()
+            self._cache()[key] = s
+
+    @cached_property
+    def settings(self):
+        """
+        Returns an object representing this organizer's settings
+        """
+        return Organizer.OrganizerSettingsProxy(self)
+
 
 class OrganizerPermission(Versionable):
     """
@@ -386,6 +439,56 @@ class Event(Versionable):
         from pretix.base.cache import EventRelatedCache
         return EventRelatedCache(self)
 
+    class EventSettingsProxy:
+        """
+        This objects allows convenient access to settings stored in the
+        EventSettings database model. It exposes all settings as properties
+        and it will do all the nasty inheritance and defaults stuff for
+        you. It will return None for non-existing properties.
+        """
+
+        def __init__(self, event):
+            self._event = event
+            self._cached_obj = None
+
+        def _cache(self):
+            if self._cached_obj is None:
+                self._cached_obj = {}
+                for setting in self._event.setting_objects.current.all():
+                    self._cached_obj[setting.key] = setting
+            return self._cached_obj
+
+        def __getattr__(self, key):
+            if key in self._cache():
+                return self._cache()[key].value
+            return getattr(self._event.organizer.settings, key)
+
+        def __setattr__(self, key, value):
+            if key.startswith('_'):
+                return super().__setattr__(key, value)
+            if key in self._cache():
+                s = self._cache()[key]
+                s = s.clone()
+            else:
+                s = EventSetting(event=self._event, key=key)
+            s.value = value
+            s.save()
+            self._cache()[key] = s
+
+        def __delattr__(self, key):
+            if key.startswith('_'):
+                return super().__delattr__(key)
+            if key in self._cache():
+                self._cache()[key].delete()
+                del self._cache()[key]
+
+    @cached_property
+    def settings(self):
+        """
+        Returns an object representing this event's settings
+        """
+        return Event.EventSettingsProxy(self)
+
 
 class EventPermission(Versionable):
     """
@@ -1320,3 +1423,26 @@ class CartPosition(Versionable):
     class Meta:
         verbose_name = _("Cart position")
         verbose_name_plural = _("Cart positions")
+
+
+class EventSetting(Versionable):
+    """
+    An event settings is a key-value setting which can be set for a
+    specific event
+    """
+    event = VersionedForeignKey(Event, related_name='setting_objects')
+    key = models.CharField(max_length=255)
+    value = models.TextField()
+
+
+class OrganizerSetting(Versionable):
+    """
+    An event option is a key-value setting which can be set for an
+    organizer. It will be inherited by the events of this organizer
+    """
+    DEFAULTS = {
+
+    }
+    organizer = VersionedForeignKey(Organizer, related_name='setting_objects')
+    key = models.CharField(max_length=255)
+    value = models.TextField()

src/pretix/base/tests/test_models.py

@@ -5,8 +5,8 @@ from django.utils.timezone import now
 from pretix.base.models import (
     Event, Organizer, Item, ItemVariation,
     Property, PropertyValue, User, Quota,
-    Order, OrderPosition, CartPosition
+    Order, OrderPosition, CartPosition,
-)
+    OrganizerSetting)
 from pretix.base.types import VariationDict
 
 
@@ -292,3 +292,67 @@ class QuotaTestCase(TestCase):
         quota2.size = 0
         quota2.save()
         self.assertEqual(self.item1.check_quotas(), (Quota.AVAILABILITY_GONE, 0))
+
+
+class SettingsTestCase(TestCase):
+
+    def setUp(self):
+        OrganizerSetting.DEFAULTS['test_default'] = 'def'
+        self.organizer = Organizer.objects.create(name='Dummy', slug='dummy')
+        self.event = Event.objects.create(
+            organizer=self.organizer, name='Dummy', slug='dummy',
+            date_from=now(),
+        )
+
+    def test_event_set_explicit(self):
+        self.event.settings.test = 'foo'
+        self.assertEqual(self.event.settings.test, 'foo')
+
+        # Reload object
+        self.event = Event.objects.get(identity=self.event.identity)
+        self.assertEqual(self.event.settings.test, 'foo')
+
+    def test_event_set_on_organizer(self):
+        self.organizer.settings.test = 'foo'
+        self.assertEqual(self.organizer.settings.test, 'foo')
+        self.assertEqual(self.event.settings.test, 'foo')
+
+        # Reload object
+        self.organizer = Organizer.objects.get(identity=self.organizer.identity)
+        self.event = Event.objects.get(identity=self.event.identity)
+        self.assertEqual(self.organizer.settings.test, 'foo')
+        self.assertEqual(self.event.settings.test, 'foo')
+
+    def test_override_organizer(self):
+        self.organizer.settings.test = 'foo'
+        self.event.settings.test = 'bar'
+        self.assertEqual(self.organizer.settings.test, 'foo')
+        self.assertEqual(self.event.settings.test, 'bar')
+
+        # Reload object
+        self.organizer = Organizer.objects.get(identity=self.organizer.identity)
+        self.event = Event.objects.get(identity=self.event.identity)
+        self.assertEqual(self.organizer.settings.test, 'foo')
+        self.assertEqual(self.event.settings.test, 'bar')
+
+    def test_default(self):
+        self.assertEqual(self.organizer.settings.test_default, 'def')
+        self.assertEqual(self.event.settings.test_default, 'def')
+
+    def test_delete(self):
+        self.organizer.settings.test = 'foo'
+        self.event.settings.test = 'bar'
+        self.assertEqual(self.organizer.settings.test, 'foo')
+        self.assertEqual(self.event.settings.test, 'bar')
+
+        del self.event.settings.test
+        self.assertEqual(self.event.settings.test, 'foo')
+
+        self.event = Event.objects.get(identity=self.event.identity)
+        self.assertEqual(self.event.settings.test, 'foo')
+
+        del self.organizer.settings.test
+        self.assertIsNone(self.organizer.settings.test)
+
+        self.organizer = Organizer.objects.get(identity=self.organizer.identity)
+        self.assertIsNone(self.organizer.settings.test)