Preview for ticket outputs

src/pretix/base/services/tickets.py

@@ -1,9 +1,14 @@
 from datetime import timedelta
 
 from django.core.files.base import ContentFile
+from django.db import transaction
 from django.utils.timezone import now
+from django.utils.translation import ugettext as _
 
-from pretix.base.models import CachedFile, CachedTicket, Order, cachedfile_name
+from pretix.base.i18n import language
+from pretix.base.models import (
+    CachedFile, CachedTicket, Event, Order, cachedfile_name,
+)
 from pretix.base.signals import register_ticket_outputs
 from pretix.celery import app
 
@@ -20,10 +25,40 @@ def generate(order: str, provider: str):
         ct.cachedfile = cf
         ct.save()
 
-    responses = register_ticket_outputs.send(order.event)
-    for receiver, response in responses:
-        prov = response(order.event)
-        if prov.identifier == provider:
-            ct.cachedfile.filename, ct.cachedfile.type, data = prov.generate(order)
-            ct.cachedfile.file.save(cachedfile_name(ct.cachedfile, ct.cachedfile.filename), ContentFile(data))
-            ct.cachedfile.save()
+    with language(order.locale):
+        responses = register_ticket_outputs.send(order.event)
+        for receiver, response in responses:
+            prov = response(order.event)
+            if prov.identifier == provider:
+                ct.cachedfile.filename, ct.cachedfile.type, data = prov.generate(order)
+                ct.cachedfile.file.save(cachedfile_name(ct.cachedfile, ct.cachedfile.filename), ContentFile(data))
+                ct.cachedfile.save()
+
+
+class DummyRollbackException(Exception):
+    pass
+
+
+def preview(event: int, provider: str):
+    event = Event.objects.get(id=event)
+    res = None
+
+    try:
+        with transaction.atomic(), language(event.settings.locale):
+            item = event.items.create(name=_("Sample product"), default_price=42.23)
+
+            order = event.orders.create(status=Order.STATUS_PENDING, datetime=now(),
+                                        expires=now(), code="PREVIEW1234", total=119)
+
+            order.positions.create(item=item, attendee_name=_("John Doe"), price=item.default_price)
+
+            responses = register_ticket_outputs.send(event)
+            for receiver, response in responses:
+                prov = response(event)
+                if prov.identifier == provider:
+                    res = prov.generate(order)
+            raise DummyRollbackException()
+    except DummyRollbackException:
+        return res
+    else:
+        raise Exception('Invalid state, should have rolled back.')