Fix #898 -- Add setting to configure subevent ordering on frontpage (#906)

Fixes #898.

src/pretix/base/models/event.py

@@ -2,6 +2,7 @@ import string
 import uuid
 from collections import OrderedDict
 from datetime import datetime, time
+from operator import attrgetter
 
 import pytz
 from django.conf import settings
@@ -535,6 +536,23 @@ class Event(EventMixin, LoggedModel):
             )
         ).order_by('date_from', 'name')
 
+    @property
+    def subevent_list_subevents(self):
+        ordering = self.settings.get('frontpage_subevent_ordering', default='date_ascending', as_type=str)
+        orderfields = {
+            'date_ascending': ('date_from', 'name'),
+            'date_descending': ('-date_from', 'name'),
+            'name_ascending': ('name', 'date_from'),
+            'name_descending': ('-name', 'date_from'),
+        }[ordering]
+        subevs = self.subevents.filter(
+            Q(active=True) & (
+                Q(Q(date_to__isnull=True) & Q(date_from__gte=now()))
+                | Q(date_to__gte=now())
+            )
+        )  # order_by doesn't make sense with I18nField
+        return sorted(subevs, key=attrgetter(*orderfields))
+
     @property
     def meta_data(self):
         data = {p.name: p.default for p in self.organizer.meta_properties.all()}

src/pretix/base/settings.py

@@ -495,6 +495,10 @@ Your {event} team"""))
         'default': '',
         'type': LazyI18nString
     },
+    'frontpage_subevent_ordering': {
+        'default': 'date_ascending',
+        'type': str
+    },
 }
 
 settings_hierarkey = Hierarkey(attribute_name='settings')

src/pretix/control/forms/event.py

@@ -6,7 +6,9 @@ from django.core.validators import RegexValidator
 from django.db.models import Q
 from django.forms import formset_factory
 from django.utils.timezone import get_current_timezone_name
-from django.utils.translation import pgettext_lazy, ugettext_lazy as _
+from django.utils.translation import (
+    pgettext, pgettext_lazy, ugettext_lazy as _,
+)
 from django_countries import Countries
 from django_countries.fields import LazyTypedChoiceField
 from i18nfield.forms import (
@@ -854,12 +856,24 @@ class DisplaySettingsForm(SettingsForm):
         label=_("Show variations of a product expanded by default"),
         required=False
     )
+    frontpage_subevent_ordering = forms.ChoiceField(
+        label=pgettext('subevent', 'Date ordering'),
+        choices=[
+            ('date_ascending', _('Event start time')),
+            ('date_descending', _('Event start time (descending)')),
+            ('name_ascending', _('Name')),
+            ('name_descending', _('Name (descending)')),
+        ],  # When adding a new ordering, remember to also define it in the event model
+    )
 
     def __init__(self, *args, **kwargs):
+        event = kwargs['obj']
         super().__init__(*args, **kwargs)
         self.fields['primary_font'].choices += [
             (a, a) for a in get_fonts()
         ]
+        if not event.has_subevents:
+            del self.fields['frontpage_subevent_ordering']
 
 
 class TicketSettingsForm(SettingsForm):

src/pretix/control/templates/pretixcontrol/event/display.html

@@ -11,6 +11,9 @@
             {% bootstrap_field form.logo_image layout="control" %}
             {% bootstrap_field form.frontpage_text layout="control" %}
             {% bootstrap_field form.show_variations_expanded layout="control" %}
+            {% if form.frontpage_subevent_ordering %}
+                {% bootstrap_field form.frontpage_subevent_ordering layout="control" %}
+            {% endif %}
         </fieldset>
         <fieldset>
             <legend>{% trans "Shop design" %}</legend>

src/pretix/presale/templates/pretixpresale/event/fragment_subevent_list.html

@@ -1,6 +1,6 @@
 {% load i18n %}
 {% load eventurl %}
-{% for subev in event.active_future_subevents %}
+{% for subev in event.subevent_list_subevents %}
     <a href="{% eventurl event "presale:event.index" subevent=subev.id cart_namespace=cart_namespace %}"
             class="subevent-row">
         <div class="row">