E-mail content: insert placeholder into text on click

src/pretix/control/forms/organizer.py

@@ -63,7 +63,9 @@ from pretix.base.forms.questions import (
     NamePartsFormField, WrappedPhoneNumberPrefixWidget, get_country_by_locale,
     get_phone_prefix,
 )
-from pretix.base.forms.widgets import SplitDateTimePickerWidget
+from pretix.base.forms.widgets import (
+    SplitDateTimePickerWidget, format_placeholders_help_text,
+)
 from pretix.base.models import (
     Customer, Device, EventMetaProperty, Gate, GiftCard, GiftCardAcceptance,
     Membership, MembershipType, OrderPosition, Organizer, ReusableMedium, Team,
@@ -568,19 +570,14 @@ class MailSettingsForm(SettingsForm):
         return placeholders
 
     def _set_field_placeholders(self, fn, base_parameters):
-        phs = [
-            '{%s}' % p
-            for p in sorted(self._get_sample_context(base_parameters).keys())
-        ]
-        ht = _('Available placeholders: {list}').format(
-            list=', '.join(phs)
-        )
+        placeholders = self._get_sample_context(base_parameters)
+        ht = format_placeholders_help_text(placeholders)
         if self.fields[fn].help_text:
             self.fields[fn].help_text += ' ' + str(ht)
         else:
             self.fields[fn].help_text = ht
         self.fields[fn].validators.append(
-            PlaceholderValidator(phs)
+            PlaceholderValidator(['{%s}' % p for p in placeholders.keys()])
         )
 
     def __init__(self, *args, **kwargs):