Add public filters based on meta data (#3673)

* Add public filters based on meta data

* Fix licenseheaders

* ignore empty values

* Fix tests

* Full non-widget implementation

* Widget support

* Add a few tests

* Allow to reorder properties

* Fix isort

* Allow to opt-out for specific events

* Fix name clash between new and old field to make migration feasible

src/pretix/control/forms/event.py

@@ -316,12 +316,12 @@ class EventMetaValueForm(forms.ModelForm):
         self.property = kwargs.pop('property')
         self.disabled = kwargs.pop('disabled')
         super().__init__(*args, **kwargs)
-        if self.property.allowed_values:
+        if self.property.choices:
             self.fields['value'] = forms.ChoiceField(
                 label=self.property.name,
                 choices=[
                     ('', _('Default ({value})').format(value=self.property.default) if self.property.default else ''),
-                ] + [(a.strip(), a.strip()) for a in self.property.allowed_values.splitlines()],
+                ] + [(a.strip(), a.strip()) for a in self.property.choice_keys],
             )
         else:
             self.fields['value'].label = self.property.name
@@ -558,6 +558,7 @@ class EventSettingsForm(EventSettingsValidationMixin, SettingsForm):
         'low_availability_percentage',
         'event_list_type',
         'event_list_available_only',
+        'event_list_filters',
         'event_calendar_future_only',
         'frontpage_text',
         'event_info_text',
@@ -645,6 +646,7 @@ class EventSettingsForm(EventSettingsValidationMixin, SettingsForm):
             del self.fields['frontpage_subevent_ordering']
             del self.fields['event_list_type']
             del self.fields['event_list_available_only']
+            del self.fields['event_list_filters']
             del self.fields['event_calendar_future_only']
 
         # create "virtual" fields for better UX when editing <name>_asked and <name>_required fields

src/pretix/control/forms/organizer.py

@@ -39,7 +39,7 @@ from django import forms
 from django.conf import settings
 from django.core.exceptions import ValidationError
 from django.db.models import Q
-from django.forms import inlineformset_factory
+from django.forms import formset_factory, inlineformset_factory
 from django.forms.utils import ErrorDict
 from django.urls import reverse
 from django.utils.crypto import get_random_string
@@ -48,7 +48,7 @@ from django.utils.safestring import mark_safe
 from django.utils.translation import gettext_lazy as _, pgettext_lazy
 from django_scopes.forms import SafeModelChoiceField
 from i18nfield.forms import (
-    I18nFormField, I18nFormSetMixin, I18nTextarea, I18nTextInput,
+    I18nForm, I18nFormField, I18nFormSetMixin, I18nTextarea, I18nTextInput,
 )
 from phonenumber_field.formfields import PhoneNumberField
 from pytz import common_timezones
@@ -195,14 +195,50 @@ class SafeOrderPositionChoiceField(forms.ModelChoiceField):
         return f'{op.order.code}-{op.positionid} ({str(op.item) + ((" - " + str(op.variation)) if op.variation else "")})'
 
 
-class EventMetaPropertyForm(forms.ModelForm):
+class EventMetaPropertyForm(I18nModelForm):
     class Meta:
         model = EventMetaProperty
-        fields = ['name', 'default', 'required', 'protected', 'allowed_values', 'filter_allowed']
+        fields = ['name', 'default', 'required', 'protected', 'filter_public', 'public_label', 'filter_allowed']
         widgets = {
-            'default': forms.TextInput()
+            'default': forms.TextInput(),
         }
 
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.fields['public_label'].widget.attrs['data-display-dependency'] = '#id_filter_public'
+
+
+class EventMetaPropertyAllowedValueForm(I18nForm):
+    key = forms.CharField(
+        label=_('Internal name'),
+        max_length=250,
+        required=True
+    )
+    label = I18nFormField(
+        label=_('Public name'),
+        required=False,
+        widget=I18nTextInput,
+        widget_kwargs=dict(attrs={
+            'placeholder': _('Public name'),
+        })
+    )
+
+
+class I18nBaseFormSet(I18nFormSetMixin, forms.BaseFormSet):
+    # compatibility shim for django-i18nfield library
+
+    def __init__(self, *args, **kwargs):
+        self.organizer = kwargs.pop('organizer', None)
+        if self.organizer:
+            kwargs['locales'] = self.organizer.settings.get('locales')
+        super().__init__(*args, **kwargs)
+
+
+EventMetaPropertyAllowedValueFormSet = formset_factory(
+    EventMetaPropertyAllowedValueForm, formset=I18nBaseFormSet,
+    can_order=True, can_delete=True, extra=0
+)
+
 
 class MembershipTypeForm(I18nModelForm):
     class Meta:

src/pretix/control/forms/subevents.py

@@ -393,12 +393,12 @@ class SubEventMetaValueForm(forms.ModelForm):
         self.default = kwargs.pop('default', None)
         self.disabled = kwargs.pop('disabled', False)
         super().__init__(*args, **kwargs)
-        if self.property.allowed_values:
+        if self.property.choices:
             self.fields['value'] = forms.ChoiceField(
                 label=self.property.name,
                 choices=[
                     ('', _('Default ({value})').format(value=self.default or self.property.default) if self.default or self.property.default else ''),
-                ] + [(a.strip(), a.strip()) for a in self.property.allowed_values.splitlines()],
+                ] + [(a.strip(), a.strip()) for a in self.property.choice_keys],
             )
         else:
             self.fields['value'].label = self.property.name

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

@@ -316,6 +316,9 @@
                 {% if sform.event_list_available_only %}
                     {% bootstrap_field sform.event_list_available_only layout="control" %}
                 {% endif %}
+                {% if sform.event_list_filters %}
+                    {% bootstrap_field sform.event_list_filters layout="control" %}
+                {% endif %}
                 {% if sform.event_calendar_future_only %}
                     {% bootstrap_field sform.event_calendar_future_only layout="control" %}
                 {% endif %}

src/pretix/control/templates/pretixcontrol/organizers/properties.html

@@ -14,29 +14,56 @@
         <span class="fa fa-plus"></span>
         {% trans "Create a new property" %}
     </a>
-    <table class="table table-condensed table-hover">
-        <thead>
-        <tr>
-            <th>{% trans "Property" %}</th>
-            <th></th>
-        </tr>
-        </thead>
-        <tbody>
-        {% for p in properties %}
+    <form method="post">
+        {% csrf_token %}
+        <table class="table table-condensed table-hover">
+            <thead>
             <tr>
-                <td><strong>
-                    <a href="{% url "control:organizer.property.edit" organizer=request.organizer.slug property=p.id %}">
-                        {{ p.name }}
-                    </a>
-                </strong></td>
-                <td class="text-right flip">
-                    <a href="{% url "control:organizer.property.edit" organizer=request.organizer.slug property=p.id %}"
-                            class="btn btn-default btn-sm"><i class="fa fa-edit"></i></a>
-                    <a href="{% url "control:organizer.property.delete" organizer=request.organizer.slug property=p.id %}"
-                            class="btn btn-danger btn-sm"><i class="fa fa-trash"></i></a>
-                </td>
+                <th>{% trans "Property" %}</th>
+                <th class="iconcol"></th>
+                <th class="iconcol"></th>
+                <th class="iconcol"></th>
+                <th class="action-col-2"></th>
+                <th class="action-col-2"></th>
             </tr>
-        {% endfor %}
-        </tbody>
-    </table>
+            </thead>
+            <tbody data-dnd-url="{% url "control:organizer.properties.reorder" organizer=request.organizer.slug %}">
+            {% for p in properties %}
+                <tr data-dnd-id="{{ p.pk }}">
+                    <td><strong>
+                        <a href="{% url "control:organizer.property.edit" organizer=request.organizer.slug property=p.id %}">
+                            {{ p.name }}
+                        </a>
+                    </strong></td>
+                    <td>
+                        {% if p.filter_allowed %}
+                            <span class="fa fa-filter text-muted" data-toggle="tooltip" title="{% trans "Can be used for filtering" %}"></span>
+                        {% endif %}
+                    </td>
+                    <td>
+                        {% if p.filter_public %}
+                            <span class="fa fa-eye text-muted" data-toggle="tooltip" title="{% trans "Show filter option to customers" %}"></span>
+                        {% endif %}
+                    </td>
+                    <td>
+                        {% if p.protected %}
+                            <span class="fa fa-lock text-muted" data-toggle="tooltip" title="{% trans "Can only be changed by organizer-level administrators" %}"></span>
+                        {% endif %}
+                    </td>
+                    <td>
+                        <button formaction="{% url "control:organizer.property.up" organizer=request.organizer.slug property=p.id %}" class="btn btn-default btn-sm sortable-up"{% if forloop.counter0 == 0 and not page_obj.has_previous %} disabled{% endif %}><i class="fa fa-arrow-up"></i></button>
+                        <button formaction="{% url "control:organizer.property.down" organizer=request.organizer.slug property=p.id %}" class="btn btn-default btn-sm sortable-down"{% if forloop.revcounter0 == 0 and not page_obj.has_next %} disabled{% endif %}><i class="fa fa-arrow-down"></i></button>
+                        <span class="dnd-container"></span>
+                    </td>
+                    <td class="text-right flip">
+                        <a href="{% url "control:organizer.property.edit" organizer=request.organizer.slug property=p.id %}"
+                                class="btn btn-default btn-sm"><i class="fa fa-edit"></i></a>
+                        <a href="{% url "control:organizer.property.delete" organizer=request.organizer.slug property=p.id %}"
+                                class="btn btn-danger btn-sm"><i class="fa fa-trash"></i></a>
+                    </td>
+                </tr>
+            {% endfor %}
+            </tbody>
+        </table>
+    </form>
 {% endblock %}

src/pretix/control/templates/pretixcontrol/organizers/property_edit.html

@@ -1,5 +1,6 @@
 {% extends "pretixcontrol/organizers/base.html" %}
 {% load i18n %}
+{% load formset_tags %}
 {% load bootstrap3 %}
 {% block inner %}
     {% if property %}
@@ -10,6 +11,78 @@
     <form class="form-horizontal" action="" method="post">
         {% csrf_token %}
         {% bootstrap_form form layout="control" %}
+
+        <div class="form-group">
+            <label class="col-md-3 control-label">
+                {% trans "Allowed values" %}<br>
+                <span class="optional">{% trans "Optional" %}</span>
+            </label>
+            <div class="col-md-9">
+                <p class="help-block">{% trans "If you keep this empty, all input will be allowed." %}</p>
+                <div class="formset tax-rules-formset" data-formset data-formset-prefix="{{ formset.prefix }}">
+                    {{ formset.management_form }}
+                    {% bootstrap_formset_errors formset %}
+                    <script type="form-template" data-formset-empty-form>
+                        {% escapescript %}
+                            <div class="row tax-rule-line" data-formset-form>
+                                <div class="sr-only">
+                                    {{ formset.empty_form.id }}
+                                    {% bootstrap_field formset.empty_form.DELETE form_group_class="" layout="inline" %}
+                                    {% bootstrap_field formset.empty_form.ORDER form_group_class="" layout="inline" %}
+                                </div>
+                                <div class="col-sm-6 col-md-4 col-lg-5">
+                                    {% bootstrap_field formset.empty_form.key layout='inline' form_group_class="" %}
+                                </div>
+                                <div class="col-sm-6 col-md-4 col-lg-5">
+                                    {% bootstrap_field formset.empty_form.label layout='inline' form_group_class="" %}
+                                </div>
+                                <div class="col-sm-6 col-md-3 col-lg-2 text-right flip">
+                                    <button type="button" class="btn btn-default" data-formset-move-up-button>
+                                        <i class="fa fa-arrow-up"></i></button>
+                                    <button type="button" class="btn btn-default" data-formset-move-down-button>
+                                        <i class="fa fa-arrow-down"></i></button>
+                                    <button type="button" class="btn btn-danger" data-formset-delete-button>
+                                        <i class="fa fa-trash"></i></button>
+                                </div>
+                            </div>
+                        {% endescapescript %}
+                    </script>
+                    <div data-formset-body class="tax-rule-lines">
+                        {% for form in formset %}
+                            {% bootstrap_form_errors form %}
+                            <div class="row tax-rule-line" data-formset-form>
+                                <div class="sr-only">
+                                    {{ form.id }}
+                                    {% bootstrap_field form.DELETE form_group_class="" layout="inline" %}
+                                    {% bootstrap_field form.ORDER form_group_class="" layout="inline" %}
+                                </div>
+                                <div class="col-sm-6 col-md-4 col-lg-5">
+                                    {% bootstrap_field form.key layout='inline' form_group_class="" %}
+                                </div>
+                                <div class="col-sm-6 col-md-4 col-lg-5">
+                                    {% bootstrap_field form.label layout='inline' form_group_class="" %}
+                                </div>
+                                <div class="col-sm-6 col-md-3 col-lg-2 text-right flip">
+                                    <button type="button" class="btn btn-default" data-formset-move-up-button>
+                                        <i class="fa fa-arrow-up"></i></button>
+                                    <button type="button" class="btn btn-default" data-formset-move-down-button>
+                                        <i class="fa fa-arrow-down"></i></button>
+                                    <button type="button" class="btn btn-danger" data-formset-delete-button>
+                                        <i class="fa fa-trash"></i></button>
+                                </div>
+                            </div>
+                        {% endfor %}
+                    </div>
+                    <div class="row tax-rule-line" data-formset-form>
+                        <div class="col-sm-12">
+                            <button type="button" class="btn btn-default" data-formset-add>
+                                <i class="fa fa-plus"></i> {% trans "Add a new value" %}</button>
+                        </div>
+                    </div>
+                </div>
+            </div>
+        </div>
+
         <div class="form-group submit-group">
             <button type="submit" class="btn btn-primary btn-save">
                 {% trans "Save" %}

src/pretix/control/templates/pretixcontrol/subevents/index.html

@@ -133,6 +133,11 @@
                                     {{ s.name }}</a></strong><br>
                                 <small class="text-muted">
                                     #{{ s.pk }}
+                                    {% for k, v in s.meta_data.items %}
+                                        {% if v %}
+                                            <small class="text-muted">&middot; {{ k }}: {{ v }}</small>
+                                        {% endif %}
+                                    {% endfor %}
                                 </small>
                             </td>
                             <td>

src/pretix/control/urls.py

@@ -126,6 +126,12 @@ urlpatterns = [
             name='organizer.property.edit'),
     re_path(r'^organizer/(?P<organizer>[^/]+)/property/(?P<property>[^/]+)/delete$', organizer.EventMetaPropertyDeleteView.as_view(),
             name='organizer.property.delete'),
+    re_path(r'^organizer/(?P<organizer>[^/]+)/property/(?P<property>[^/]+)/up$', organizer.meta_property_move_up,
+            name='organizer.property.up'),
+    re_path(r'^organizer/(?P<organizer>[^/]+)/property/(?P<property>[^/]+)/down$', organizer.meta_property_move_down,
+            name='organizer.property.down'),
+    re_path(r'^organizer/(?P<organizer>[^/]+)/property/reorder$', organizer.reorder_meta_properties,
+            name='organizer.properties.reorder'),
     re_path(r'^organizer/(?P<organizer>[^/]+)/membershiptypes$', organizer.MembershipTypeListView.as_view(), name='organizer.membershiptypes'),
     re_path(r'^organizer/(?P<organizer>[^/]+)/membershiptype/add$', organizer.MembershipTypeCreateView.as_view(),
             name='organizer.membershiptype.add'),

src/pretix/control/views/organizer.py

@@ -37,6 +37,7 @@ import re
 from datetime import time, timedelta
 from decimal import Decimal
 from hashlib import sha1
+from json import JSONDecodeError
 
 import bleach
 import dateutil
@@ -52,7 +53,9 @@ from django.db.models import (
 )
 from django.db.models.functions import Coalesce, Greatest
 from django.forms import DecimalField
-from django.http import HttpResponse, HttpResponseBadRequest, JsonResponse
+from django.http import (
+    Http404, HttpResponse, HttpResponseBadRequest, JsonResponse,
+)
 from django.shortcuts import get_object_or_404, redirect
 from django.urls import reverse
 from django.utils.formats import date_format
@@ -60,6 +63,7 @@ from django.utils.functional import cached_property
 from django.utils.timezone import get_current_timezone, now
 from django.utils.translation import gettext, gettext_lazy as _
 from django.views import View
+from django.views.decorators.http import require_http_methods
 from django.views.generic import (
     CreateView, DetailView, FormView, ListView, TemplateView, UpdateView,
 )
@@ -97,17 +101,19 @@ from pretix.control.forms.filter import (
 from pretix.control.forms.orders import ExporterForm
 from pretix.control.forms.organizer import (
     CustomerCreateForm, CustomerUpdateForm, DeviceBulkEditForm, DeviceForm,
-    EventMetaPropertyForm, GateForm, GiftCardAcceptanceInviteForm,
-    GiftCardCreateForm, GiftCardUpdateForm, MailSettingsForm,
-    MembershipTypeForm, MembershipUpdateForm, OrganizerDeleteForm,
-    OrganizerFooterLinkFormset, OrganizerForm, OrganizerSettingsForm,
-    OrganizerUpdateForm, ReusableMediumCreateForm, ReusableMediumUpdateForm,
-    SSOClientForm, SSOProviderForm, TeamForm, WebHookForm,
+    EventMetaPropertyAllowedValueFormSet, EventMetaPropertyForm, GateForm,
+    GiftCardAcceptanceInviteForm, GiftCardCreateForm, GiftCardUpdateForm,
+    MailSettingsForm, MembershipTypeForm, MembershipUpdateForm,
+    OrganizerDeleteForm, OrganizerFooterLinkFormset, OrganizerForm,
+    OrganizerSettingsForm, OrganizerUpdateForm, ReusableMediumCreateForm,
+    ReusableMediumUpdateForm, SSOClientForm, SSOProviderForm, TeamForm,
+    WebHookForm,
 )
 from pretix.control.forms.rrule import RRuleForm
 from pretix.control.logdisplay import OVERVIEW_BANLIST
 from pretix.control.permissions import (
     AdministratorPermissionRequiredMixin, OrganizerPermissionRequiredMixin,
+    organizer_permission_required,
 )
 from pretix.control.signals import nav_organizer
 from pretix.control.views import PaginationMixin
@@ -2043,14 +2049,54 @@ class EventMetaPropertyListView(OrganizerDetailViewMixin, OrganizerPermissionReq
         return self.request.organizer.meta_properties.all()
 
 
-class EventMetaPropertyCreateView(OrganizerDetailViewMixin, OrganizerPermissionRequiredMixin, CreateView):
-    model = EventMetaProperty
+class EventMetaPropertyEditorMixin:
     template_name = 'pretixcontrol/organizers/property_edit.html'
-    permission = 'can_change_organizer_settings'
     form_class = EventMetaPropertyForm
 
+    @cached_property
+    def formset(self):
+        return EventMetaPropertyAllowedValueFormSet(
+            data=self.request.POST if self.request.method == "POST" else None,
+            organizer=self.request.organizer,
+            initial=(self.object.choices or []) if self.object else [],
+        )
+
+    def get_context_data(self, **kwargs):
+        ctx = super().get_context_data(**kwargs)
+        ctx['formset'] = self.formset
+        return ctx
+
+    def get_form_kwargs(self):
+        return {
+            **super().get_form_kwargs(),
+            'event': self.request.organizer,
+        }
+
+    def is_default_valid(self):
+        choice_keys = [
+            f.cleaned_data.get("key") for f in self.formset.ordered_forms if f not in self.formset.deleted_forms
+        ]
+        default = self.form.cleaned_data["default"]
+        if default and choice_keys and default not in choice_keys:
+            messages.error(self.request, _("You cannot set a default value that is not a valid value."))
+            return False
+        return True
+
+    def post(self, request, *args, **kwargs):
+        self.object = self.get_object(self.get_queryset())
+        self.form = self.get_form()
+        if self.form.is_valid() and self.formset.is_valid() and self.is_default_valid():
+            return self.form_valid(self.form)
+        else:
+            return self.form_invalid(self.form)
+
+
+class EventMetaPropertyCreateView(OrganizerDetailViewMixin, OrganizerPermissionRequiredMixin, EventMetaPropertyEditorMixin, CreateView):
+    model = EventMetaProperty
+    permission = 'can_change_organizer_settings'
+
     def get_object(self, queryset=None):
-        return get_object_or_404(EventMetaProperty, organizer=self.request.organizer, pk=self.kwargs.get('property'))
+        return EventMetaProperty()
 
     def get_success_url(self):
         return reverse('control:organizer.properties', kwargs={
@@ -2060,6 +2106,9 @@ class EventMetaPropertyCreateView(OrganizerDetailViewMixin, OrganizerPermissionR
     def form_valid(self, form):
         messages.success(self.request, _('The property has been created.'))
         form.instance.organizer = self.request.organizer
+        form.instance.choices = [
+            f.cleaned_data for f in self.formset.ordered_forms if f not in self.formset.deleted_forms
+        ]
         ret = super().form_valid(form)
         form.instance.log_action('pretix.property.created', user=self.request.user, data={
             k: getattr(self.object, k) for k in form.changed_data
@@ -2071,12 +2120,10 @@ class EventMetaPropertyCreateView(OrganizerDetailViewMixin, OrganizerPermissionR
         return super().form_invalid(form)
 
 
-class EventMetaPropertyUpdateView(OrganizerDetailViewMixin, OrganizerPermissionRequiredMixin, UpdateView):
+class EventMetaPropertyUpdateView(OrganizerDetailViewMixin, OrganizerPermissionRequiredMixin, EventMetaPropertyEditorMixin, UpdateView):
     model = EventMetaProperty
-    template_name = 'pretixcontrol/organizers/property_edit.html'
     permission = 'can_change_organizer_settings'
     context_object_name = 'property'
-    form_class = EventMetaPropertyForm
 
     def get_object(self, queryset=None):
         return get_object_or_404(EventMetaProperty, organizer=self.request.organizer, pk=self.kwargs.get('property'))
@@ -2087,7 +2134,10 @@ class EventMetaPropertyUpdateView(OrganizerDetailViewMixin, OrganizerPermissionR
         })
 
     def form_valid(self, form):
-        if form.has_changed():
+        form.instance.choices = [
+            f.cleaned_data for f in self.formset.ordered_forms if f not in self.formset.deleted_forms
+        ]
+        if form.has_changed() or self.formset.has_changed():
             self.object.log_action('pretix.property.changed', user=self.request.user, data={
                 k: getattr(self.object, k)
                 for k in form.changed_data
@@ -2124,6 +2174,75 @@ class EventMetaPropertyDeleteView(OrganizerDetailViewMixin, OrganizerPermissionR
         return redirect(success_url)
 
 
+def meta_property_move(request, property, up=True):
+    property = get_object_or_404(request.organizer.meta_properties, id=property)
+    properties = list(request.organizer.meta_properties.order_by("position"))
+
+    index = properties.index(property)
+    if index != 0 and up:
+        properties[index - 1], properties[index] = properties[index], properties[index - 1]
+    elif index != len(properties) - 1 and not up:
+        properties[index + 1], properties[index] = properties[index], properties[index + 1]
+
+    for i, prop in enumerate(properties):
+        if prop.position != i:
+            prop.position = i
+            prop.save()
+            prop.log_action(
+                'pretix.property.reordered', user=request.user, data={
+                    'position': i,
+                }
+            )
+    messages.success(request, _('The order of properties has been updated.'))
+
+
+@organizer_permission_required("can_change_organizer_settings")
+@require_http_methods(["POST"])
+def meta_property_move_up(request, organizer, property):
+    meta_property_move(request, property, up=True)
+    return redirect('control:organizer.properties',
+                    organizer=request.organizer.slug)
+
+
+@organizer_permission_required("can_change_organizer_settings")
+@require_http_methods(["POST"])
+def meta_property_move_down(request, organizer, property):
+    meta_property_move(request, property, up=False)
+    return redirect('control:organizer.properties',
+                    organizer=request.organizer.slug)
+
+
+@transaction.atomic
+@organizer_permission_required("can_change_items")
+@require_http_methods(["POST"])
+def reorder_meta_properties(request, organizer):
+    try:
+        ids = json.loads(request.body.decode('utf-8'))['ids']
+    except (JSONDecodeError, KeyError, ValueError):
+        return HttpResponseBadRequest("expected JSON: {ids:[]}")
+
+    input_meta_properties = list(request.organizer.meta_properties.filter(id__in=[i for i in ids if i.isdigit()]))
+
+    if len(input_meta_properties) != len(ids):
+        raise Http404(_("Some of the provided object ids are invalid."))
+
+    if len(input_meta_properties) != request.organizer.meta_properties.count():
+        raise Http404(_("Not all objects have been selected."))
+
+    for c in input_meta_properties:
+        pos = ids.index(str(c.pk))
+        if pos != c.position:  # Save unneccessary UPDATE queries
+            c.position = pos
+            c.save(update_fields=['position'])
+            c.log_action(
+                'pretix.property.reordered', user=request.user, data={
+                    'position': pos,
+                }
+            )
+
+    return HttpResponse()
+
+
 class LogView(OrganizerPermissionRequiredMixin, PaginationMixin, ListView):
     template_name = 'pretixcontrol/organizers/logs.html'
     permission = 'can_change_organizer_settings'

src/pretix/control/views/subevents.py

@@ -120,7 +120,10 @@ class SubEventList(EventPermissionRequiredMixin, PaginationMixin, SubEventQueryM
     permission = 'can_change_settings'
 
     def get_queryset(self):
-        return super().get_queryset(True)
+        return super().get_queryset(True).prefetch_related(
+            'meta_values',
+            'meta_values__property',
+        )
 
     def get_context_data(self, **kwargs):
         ctx = super().get_context_data(**kwargs)