Refs #678 -- Allow deletion of events that do not have any orders

src/pretix/control/forms/event.py

@@ -1,5 +1,6 @@
 from django import forms
 from django.conf import settings
+from django.contrib.auth.hashers import check_password
 from django.core.exceptions import ValidationError
 from django.core.validators import RegexValidator
 from django.db.models import Q
@@ -951,3 +952,43 @@ class WidgetCodeForm(forms.Form):
             raise ValidationError(_('The given voucher code does not exist.'))
 
         return v
+
+
+class EventDeleteForm(forms.Form):
+    error_messages = {
+        'pw_current_wrong': _("The password you entered was not correct."),
+        'slug_wrong': _("The slug you entered was not correct."),
+    }
+    user_pw = forms.CharField(
+        max_length=255,
+        label=_("New password"),
+        widget=forms.PasswordInput()
+    )
+    slug = forms.CharField(
+        max_length=255,
+        label=_("Event slug"),
+    )
+
+    def __init__(self, *args, **kwargs):
+        self.event = kwargs.pop('event')
+        self.user = kwargs.pop('user')
+        super().__init__(*args, **kwargs)
+
+    def clean_user_pw(self):
+        user_pw = self.cleaned_data.get('user_pw')
+        if not check_password(user_pw, self.user.password):
+            raise forms.ValidationError(
+                self.error_messages['pw_current_wrong'],
+                code='pw_current_wrong',
+            )
+
+        return user_pw
+
+    def clean_slug(self):
+        slug = self.cleaned_data.get('slug')
+        if slug != self.event.slug:
+            raise forms.ValidationError(
+                self.error_messages['slug_wrong'],
+                code='slug_wrong',
+            )
+        return slug