Use a context manager for temporary locale switches

src/pretix/base/i18n.py

@@ -1,5 +1,6 @@
 import copy
 import json
+from contextlib import contextmanager
 
 from django import forms
 from django.conf import settings
@@ -75,11 +76,8 @@ class LazyI18nString:
             self.lazygettext = lazygettext
 
         def __getitem__(self, item):
-            lng = translation.get_language()
-            translation.activate(item)
-            s = str(ugettext(self.lazygettext))
-            translation.activate(lng)
-            return s
+            with language(item):
+                return str(ugettext(self.lazygettext))
 
         def __contains__(self, item):
             return True
@@ -334,3 +332,13 @@ class LazyNumber:
 
     def __str__(self):
         return number_format(self.value, decimal_pos=self.decimal_pos)
+
+
+@contextmanager
+def language(lng):
+    _lng = translation.get_language()
+    translation.activate(lng or settings.LANGUAGE_CODE)
+    try:
+        yield
+    finally:
+        translation.activate(_lng)

src/pretix/base/services/invoices.py

@@ -22,6 +22,7 @@ from reportlab.platypus import (
     Table, TableStyle,
 )
 
+from pretix.base.i18n import language
 from pretix.base.models import Invoice, InvoiceAddress, InvoiceLine, Order
 from pretix.base.signals import register_payment_providers
 
@@ -47,12 +48,11 @@ def generate_cancellation(invoice: Invoice):
 @transaction.atomic
 def generate_invoice(order: Order):
     locale = order.event.settings.get('invoice_language')
-    _lng = translation.get_language()
     if locale:
         if locale == '__user__':
             locale = order.locale
-        translation.activate(locale or settings.LANGUAGE_CODE)
 
+    with language(locale):
         i = Invoice(order=order, event=order.event)
         i.invoice_from = order.event.settings.get('invoice_address_from')
         i.additional_text = order.event.settings.get('invoice_additional_text')
@@ -97,7 +97,6 @@ def generate_invoice(order: Order):
                 tax_rate=order.payment_fee_tax_rate
             )
 
-    translation.activate(_lng)
         invoice_pdf(i.pk)
 
 
@@ -316,16 +315,12 @@ def _invoice_generate_german(invoice, f):
 
 def invoice_pdf(invoice: int):
     i = Invoice.objects.get(pk=invoice)
-    _lng = translation.get_language()
-    translation.activate(i.locale)
-
+    with language(i.locale):
         with tempfile.NamedTemporaryFile(suffix=".pdf") as f:
             _invoice_generate_german(i, f)
             f.seek(0)
             i.file.save('invoice.pdf', ContentFile(f.read()))
         i.save()
-
-    translation.activate(_lng)
         return i.file.name
 
 

src/pretix/base/services/mail.py

@@ -7,7 +7,7 @@ from django.utils import translation
 from django.utils.translation import ugettext as _
 from typing import Any, Dict
 
-from pretix.base.i18n import LazyI18nString
+from pretix.base.i18n import LazyI18nString, language
 from pretix.base.models import Event
 
 logger = logging.getLogger('pretix.base.mail')
@@ -39,10 +39,7 @@ def mail(email: str, subject: str, template: str,
     the email has been sent, just that it has been queued by the e-mail
     backend.
     """
-    _lng = translation.get_language()
-    if locale:
-        translation.activate(locale or settings.LANGUAGE_CODE)
-
+    with language(locale):
         if isinstance(template, LazyI18nString):
             body = str(template)
             if context:
@@ -64,10 +61,7 @@ def mail(email: str, subject: str, template: str,
                 "You are receiving this e-mail because you placed an order for {event}."
             ).format(event=event.name)
             body += "\r\n"
-    try:
         return mail_send([email], subject, body, sender, event.id if event else None)
-    finally:
-        translation.activate(_lng)
 
 
 def mail_send(to: str, subject: str, body: str, sender: str, event: int=None) -> bool:

src/pretix/base/services/orders.py

@@ -2,11 +2,12 @@ from datetime import datetime, timedelta
 
 from django.conf import settings
 from django.db import transaction
+from django.utils import translation
 from django.utils.timezone import now
 from django.utils.translation import ugettext_lazy as _
 from typing import List
 
-from pretix.base.i18n import LazyDate, LazyNumber
+from pretix.base.i18n import LazyDate, LazyNumber, language
 from pretix.base.models import (
     CartPosition, Event, EventLock, Order, OrderPosition, Quota, User,
 )
@@ -231,6 +232,7 @@ def _create_order(event: Event, email: str, positions: List[CartPosition], dt: d
 
 def _perform_order(event: str, payment_provider: str, position_ids: List[str],
                    email: str, locale: str, address: int):
+
     event = Event.objects.get(id=event)
     responses = register_payment_providers.send(event)
     pprov = None
@@ -266,6 +268,7 @@ def _perform_order(event: str, payment_provider: str, position_ids: List[str],
     if event.settings.get('invoice_generate'):
         generate_invoice(order)
 
+    with language(order.locale):
         mail(
             order.email, _('Your order: %(code)s') % {'code': order.code},
             event.settings.mail_text_order_placed,
@@ -282,6 +285,7 @@ def _perform_order(event: str, payment_provider: str, position_ids: List[str],
             },
             event, locale=order.locale
         )
+
     return order.id
 
 

src/pretix/control/views/orders.py

@@ -7,11 +7,12 @@ from django.core.urlresolvers import reverse
 from django.db.models import Q
 from django.http import Http404, HttpResponseNotAllowed
 from django.shortcuts import redirect, render
-from django.utils.functional import cached_property
+from django.utils.functional import cached_property, lazy
 from django.utils.timezone import now
-from django.utils.translation import ugettext_lazy as _
+from django.utils.translation import gettext, ugettext_lazy as _
 from django.views.generic import DetailView, ListView, TemplateView, View
 
+from pretix.base.i18n import language
 from pretix.base.models import (
     CachedFile, CachedTicket, EventLock, Invoice, Item, Order, Quota,
 )
@@ -206,8 +207,10 @@ class OrderResendLink(OrderView):
     permission = 'can_change_orders'
 
     def post(self, *args, **kwargs):
+        with language(self.order.locale):
             mail(
-            self.order.email, _('Your order: %(code)s') % {'code': self.order.code},
+                self.order.email,
+                _('Your order: %(code)s') % {'code': self.order.code},
                 self.order.event.settings.mail_text_resend_link,
                 {
                     'event': self.order.event.name,