Use localized settings for bank_details (#176)

This is a non-destructive upgrade since LazyI18nString will return a
normal string (which is content of the settings variable up until now)
as-is.

src/pretix/plugins/banktransfer/payment.py

@@ -5,6 +5,7 @@ from django import forms
 from django.template.loader import get_template
 from django.utils.translation import ugettext_lazy as _
 
+from pretix.base.i18n import I18nFormField, I18nTextarea, LazyI18nString
 from pretix.base.payment import BasePaymentProvider
 
 
@@ -14,19 +15,22 @@ class BankTransfer(BasePaymentProvider):
 
     @property
     def settings_form_fields(self):
+        form_field = I18nFormField(
+            label=_('Bank account details'),
+            widget=I18nTextarea,
+        )
+        form_field.widget.enabled_langcodes = self.event.settings.get('locales')
         return OrderedDict(
-            list(super().settings_form_fields.items()) + [
+            list(super().settings_form_fields.items()) + [('bank_details', form_field)]
-                ('bank_details',
-                 forms.CharField(
-                     widget=forms.Textarea,
-                     label=_('Bank account details'),
-                 ))
-            ]
         )
 
     def payment_form_render(self, request) -> str:
         template = get_template('pretixplugins/banktransfer/checkout_payment_form.html')
-        ctx = {'request': request, 'event': self.event, 'settings': self.settings}
+        ctx = {
+            'request': request,
+            'event': self.event,
+            'details': self.settings.get('bank_details', as_type=LazyI18nString),
+        }
         return template.render(ctx)
 
     def checkout_prepare(self, request, total):
@@ -40,12 +44,20 @@ class BankTransfer(BasePaymentProvider):
 
     def order_pending_mail_render(self, order) -> str:
         template = get_template('pretixplugins/banktransfer/email/order_pending.txt')
-        ctx = {'event': self.event, 'order': order, 'settings': self.settings}
+        ctx = {
+            'event': self.event,
+            'order': order,
+            'details': self.settings.get('bank_details', as_type=LazyI18nString),
+        }
         return template.render(ctx)
 
     def order_pending_render(self, request, order) -> str:
         template = get_template('pretixplugins/banktransfer/pending.html')
-        ctx = {'request': request, 'order': order, 'settings': self.settings}
+        ctx = {
+            'event': self.event,
+            'order': order,
+            'details': self.settings.get('bank_details', as_type=LazyI18nString),
+        }
         return template.render(ctx)
 
     def order_control_render(self, request, order) -> str:
@@ -54,6 +66,6 @@ class BankTransfer(BasePaymentProvider):
         else:
             payment_info = None
         template = get_template('pretixplugins/banktransfer/control.html')
-        ctx = {'request': request, 'event': self.event, 'settings': self.settings,
+        ctx = {'request': request, 'event': self.event,
                'payment_info': payment_info, 'order': order}
         return template.render(ctx)

src/pretix/plugins/banktransfer/templates/pretixplugins/banktransfer/checkout_payment_form.html

@@ -6,7 +6,7 @@
 {% endblocktrans %}</p>
 
 <address>
-    {{ settings.bank_details|linebreaksbr }}<br>
+    {{ details|linebreaksbr }}<br>
     <strong>
         {% trans "We will assign you a personal reference code to use after you completed the order." %}
     </strong>

src/pretix/plugins/banktransfer/templates/pretixplugins/banktransfer/email/order_pending.txt

@@ -1,4 +1,4 @@
-{% load i18n %}{% load l10n %}{% blocktrans with bank=settings.bank_details code=order.full_code total=order.total|localize currency=event.currency %}
+{% load i18n %}{% load l10n %}{% blocktrans with bank=details code=order.full_code total=order.total|localize currency=event.currency %}
 Please transfer the full amount to the following bank account.
 
 Reference: {{ code }}

src/pretix/plugins/banktransfer/templates/pretixplugins/banktransfer/pending.html

@@ -6,7 +6,7 @@
 {% endblocktrans %}</p>
 
 <address>
-    {{ settings.bank_details|linebreaksbr }}<br />
+    {{ details|linebreaksbr }}<br />
     {% trans "Amount:" %} {{ order.total|localize }} {{ request.event.currency }}<br />
     <strong>{% trans "Reference code (important):" %} {{ order.full_code }}</strong>
 </address>