Add pluggable ticket secret generators (#1809)

src/pretix/control/forms/event.py

@@ -1069,6 +1069,20 @@ class TicketSettingsForm(SettingsForm):
         'ticket_download_pending',
         'ticket_download_require_validated_email',
     ]
+    ticket_secret_generator = forms.ChoiceField(
+        label=_("Ticket code generator"),
+        help_text=_("For advanced users, usually does not need to be changed."),
+        required=True,
+        widget=forms.RadioSelect,
+        choices=[]
+    )
+
+    def __init__(self, *args, **kwargs):
+        event = kwargs.get('obj')
+        super().__init__(*args, **kwargs)
+        self.fields['ticket_secret_generator'].choices = [
+            (r.identifier, r.verbose_name) for r in event.ticket_secret_generators.values()
+        ]
 
     def prepare_fields(self):
         # See clean()

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

@@ -62,6 +62,10 @@
                 <legend>{% trans "Download time" %}</legend>
                 {% bootstrap_field form.ticket_download_date layout="control" %}
             </fieldset>
+            <fieldset>
+                <legend>{% trans "Ticket codes" %}</legend>
+                {% bootstrap_field form.ticket_secret_generator layout="control" %}
+            </fieldset>
         </div>
         <div class="form-group submit-group">
             <button type="submit" class="btn btn-primary btn-save">

src/pretix/control/views/orders.py

@@ -40,13 +40,14 @@ from pretix.base.i18n import language
 from pretix.base.models import (
     CachedCombinedTicket, CachedFile, CachedTicket, Checkin, Invoice,
     InvoiceAddress, Item, ItemVariation, LogEntry, Order, QuestionAnswer,
-    Quota, generate_position_secret, generate_secret,
+    Quota, generate_secret,
 )
 from pretix.base.models.orders import (
     CancellationRequest, OrderFee, OrderPayment, OrderPosition, OrderRefund,
 )
 from pretix.base.models.tax import EU_COUNTRIES, cc_to_vat_prefix
 from pretix.base.payment import PaymentException
+from pretix.base.secrets import assign_ticket_secret
 from pretix.base.services import tickets
 from pretix.base.services.cancelevent import cancel_event
 from pretix.base.services.export import export
@@ -1644,8 +1645,9 @@ class OrderContactChange(OrderView):
                 changed = True
                 self.order.secret = generate_secret()
                 for op in self.order.all_positions.all():
-                    op.secret = generate_position_secret()
-                    op.save()
+                    assign_ticket_secret(
+                        self.request.event, position=op, force_invalidate=True, save=True
+                    )
                 tickets.invalidate_cache.apply_async(kwargs={'event': self.request.event.pk, 'order': self.order.pk})
                 self.order.log_action('pretix.event.order.secret.changed', user=self.request.user)