Allow creating KnownDomains in the interface

src/pretix/control/forms/organizer.py

@@ -3,6 +3,7 @@ from django.utils.translation import ugettext_lazy as _
 
 from pretix.base.forms import I18nModelForm
 from pretix.base.models import Organizer
+from pretix.multidomain.models import KnownDomain
 
 
 class OrganizerForm(I18nModelForm):
@@ -25,9 +26,42 @@ class OrganizerForm(I18nModelForm):
 
 
 class OrganizerUpdateForm(OrganizerForm):
+
     def __init__(self, *args, **kwargs):
+        self.domain = kwargs.pop('domain', False)
+        kwargs.setdefault('initial', {})
+        self.instance = kwargs['instance']
+        if self.domain and self.instance:
+            initial_domain = self.instance.domains.first()
+            if initial_domain:
+                kwargs['initial'].setdefault('domain', initial_domain.domainname)
+
         super().__init__(*args, **kwargs)
         self.fields['slug'].widget.attrs['readonly'] = 'readonly'
+        if self.domain:
+            self.fields['domain'] = forms.CharField(
+                max_length=255,
+                label=_('Custom domain'),
+                required=False,
+                help_text=_('You need to configure the custom domain in the webserver beforehand.')
+            )
 
     def clean_slug(self):
         return self.instance.slug
+
+    def save(self, commit=True):
+        instance = super().save(commit)
+
+        if self.domain:
+            current_domain = instance.domains.first()
+            if self.cleaned_data['domain']:
+                if current_domain and current_domain.domainname != self.cleaned_data['domain']:
+                    current_domain.delete()
+                    KnownDomain.objects.create(organizer=instance, domainname=self.cleaned_data['domain'])
+                elif not current_domain:
+                    KnownDomain.objects.create(organizer=instance, domainname=self.cleaned_data['domain'])
+            elif current_domain:
+                current_domain.delete()
+            instance.get_cache().clear()
+
+        return instance