Fix #467 -- Pluggable email placeholders (#1429)

* Fix #467 -- Pluggable email placeholders

* Previews

* Polishing

* Fix tests

* Add missing doc file

src/pretix/control/views/event.py

@@ -1,7 +1,6 @@
 import json
 import re
 from collections import OrderedDict
-from datetime import timedelta
 from decimal import Decimal
 from urllib.parse import urlsplit
 
@@ -18,7 +17,6 @@ from django.http import (
 from django.shortcuts import get_object_or_404, redirect
 from django.urls import reverse
 from django.utils import translation
-from django.utils.formats import date_format
 from django.utils.functional import cached_property
 from django.utils.timezone import now
 from django.utils.translation import ugettext, ugettext_lazy as _
@@ -29,7 +27,7 @@ from i18nfield.strings import LazyI18nString
 from pytz import timezone
 
 from pretix.base.channels import get_all_sales_channels
-from pretix.base.i18n import LazyCurrencyNumber
+from pretix.base.email import get_available_placeholders
 from pretix.base.models import (
     Event, LogEntry, Order, RequiredAction, TaxRule, Voucher,
 )
@@ -37,7 +35,6 @@ from pretix.base.models.event import EventMetaValue
 from pretix.base.services import tickets
 from pretix.base.services.invoices import build_preview_invoice_pdf
 from pretix.base.signals import register_ticket_outputs
-from pretix.base.templatetags.money import money_filter
 from pretix.base.templatetags.rich_text import markdown_compile_email
 from pretix.control.forms.event import (
     CancelSettingsForm, CommentForm, EventDeleteForm, EventMetaValueForm,
@@ -48,7 +45,6 @@ from pretix.control.forms.event import (
 )
 from pretix.control.permissions import EventPermissionRequiredMixin
 from pretix.helpers.database import rolledback_transaction
-from pretix.helpers.urls import build_absolute_uri
 from pretix.multidomain.urlreverse import get_domain
 from pretix.plugins.stripe.payment import StripeSettingsHolder
 from pretix.presale.style import regenerate_css
@@ -538,20 +534,6 @@ class MailSettingsPreview(EventPermissionRequiredMixin, View):
         def __missing__(self, key):
             return '{' + key + '}'
 
-    @staticmethod
-    def generate_order_fullname(slug, code):
-        return '{event}-{code}'.format(event=slug.upper(), code=code)
-
-    # create data which depend on locale
-    def localized_data(self):
-        return {
-            'date': date_format(now() + timedelta(days=7), 'SHORT_DATE_FORMAT'),
-            'expire_date': date_format(now() + timedelta(days=15), 'SHORT_DATE_FORMAT'),
-            'payment_info': _('{} has been transferred to account <9999-9999-9999-9999> at {}').format(
-                money_filter(Decimal('42.23'), self.request.event.currency),
-                date_format(now(), 'SHORT_DATETIME_FORMAT'))
-        }
-
     # create index-language mapping
     @cached_property
     def supported_locale(self):
@@ -561,91 +543,23 @@ class MailSettingsPreview(EventPermissionRequiredMixin, View):
                 locales[str(idx)] = val[0]
         return locales
 
-    @cached_property
-    def meta_properties(self):
-        return [p.name for p in self.request.organizer.meta_properties.all()]
-
-    @cached_property
-    def items(self):
-        kv = {
-            'mail_text_order_placed': ['total', 'currency', 'date', 'invoice_company', 'total_with_currency',
-                                       'event', 'payment_info', 'url', 'invoice_name'],
-            'mail_text_order_placed_attendee': ['event', 'url', 'attendee_name'],
-            'mail_text_order_paid': ['event', 'url', 'invoice_name', 'invoice_company', 'payment_info'],
-            'mail_text_order_paid_attendee': ['event', 'url', 'attendee_name'],
-            'mail_text_order_free': ['event', 'url', 'invoice_name', 'invoice_company'],
-            'mail_text_order_free_attendee': ['event', 'url', 'attendee_name'],
-            'mail_text_resend_link': ['event', 'url', 'invoice_name', 'invoice_company'],
-            'mail_text_resend_all_links': ['event', 'orders'],
-            'mail_text_order_changed': ['event', 'url', 'invoice_name', 'invoice_company'],
-            'mail_text_order_expire_warning': ['event', 'url', 'expire_date', 'invoice_name', 'invoice_company'],
-            'mail_text_waiting_list': ['event', 'url', 'product', 'hours', 'code'],
-            'mail_text_order_canceled': ['code', 'event', 'url'],
-            'mail_text_order_custom_mail': ['expire_date', 'event', 'code', 'date', 'url',
-                                            'invoice_name', 'invoice_company'],
-            'mail_text_download_reminder': ['event', 'url'],
-            'mail_text_download_reminder_attendee': ['attendee_name', 'event', 'url'],
-            'mail_text_order_placed_require_approval': ['total', 'currency', 'date', 'invoice_company',
-                                                        'total_with_currency', 'event', 'url', 'invoice_name'],
-            'mail_text_order_approved': ['total', 'currency', 'date', 'invoice_company',
-                                         'total_with_currency', 'event', 'url', 'invoice_name'],
-            'mail_text_order_denied': ['total', 'currency', 'date', 'invoice_company',
-                                       'total_with_currency', 'event', 'url', 'invoice_name'],
-        }
-        for v in kv.values():
-            for p in self.meta_properties:
-                v.append('meta_' + p)
-        return kv
-
-    @cached_property
-    def base_data(self):
-        user_orders = [
-            {'code': 'F8VVL', 'secret': '6zzjnumtsx136ddy'},
-            {'code': 'HIDHK', 'secret': '98kusd8ofsj8dnkd'},
-            {'code': 'OPKSB', 'secret': '09pjdksflosk3njd'}
-        ]
-        orders = [' - {} - {}'.format(self.generate_order_fullname(self.request.event.slug, order['code']),
-                                      self.generate_order_url(order['code'], order['secret']))
-                  for order in user_orders]
-        d = {
-            'event': self.request.event.name,
-            'total': 42.23,
-            'total_with_currency': LazyCurrencyNumber(42.23, self.request.event.currency),
-            'currency': self.request.event.currency,
-            'url': self.generate_order_url(user_orders[0]['code'], user_orders[0]['secret']),
-            'orders': '\n'.join(orders),
-            'hours': self.request.event.settings.waiting_list_hours,
-            'product': _('Sample Admission Ticket'),
-            'code': '68CYU2H6ZTP3WLK5',
-            'invoice_name': _('John Doe'),
-            'invoice_company': _('Sample Corporation'),
-            'common': _('An individual text with a reason can be inserted here.'),
-            'payment_info': _('Please transfer money to this bank account: 9999-9999-9999-9999'),
-            'attendee_name': _('John Doe'),
-        }
-        for k, v in self.request.event.meta_data.items():
-            d['meta_' + k] = v
-        return d
-
-    def generate_order_url(self, code, secret):
-        return build_absolute_uri('presale:event.order', kwargs={
-            'event': self.request.event.slug,
-            'organizer': self.request.event.organizer.slug,
-            'order': code,
-            'secret': secret
-        })
-
     # get all supported placeholders with dummy values
     def placeholders(self, item):
-        supported = {}
-        local_data = self.localized_data()
-        for key in self.items.get(item):
-            supported[key] = self.base_data.get(key) if key in self.base_data else local_data.get(key)
-        return self.SafeDict(supported)
+        ctx = {}
+        for p in get_available_placeholders(self.request.event, MailSettingsForm.base_context[item]).values():
+            s = str(p.render_sample(self.request.event))
+            if s.strip().startswith('*'):
+                ctx[p.identifier] = s
+            else:
+                ctx[p.identifier] = '<span class="placeholder" title="{}">{}</span>'.format(
+                    _('This value will be replaced based on dynamic parameters.'),
+                    s
+                )
+        return self.SafeDict(ctx)
 
     def post(self, request, *args, **kwargs):
         preview_item = request.POST.get('item', '')
-        if preview_item not in self.items:
+        if preview_item not in MailSettingsForm.base_context:
             return HttpResponseBadRequest(_('invalid item'))
 
         regex = r"^" + re.escape(preview_item) + r"_(?P<idx>[\d+])$"