Questions at check-in time (#745)

Questions at check-in time

src/pretix/presale/views/questions.py

@@ -3,9 +3,12 @@ from collections import OrderedDict
 
 from django import forms
 from django.core.files.uploadedfile import UploadedFile
+from django.db.models import Prefetch
 from django.utils.functional import cached_property
 
-from pretix.base.models import CartPosition, OrderPosition, QuestionAnswer
+from pretix.base.models import (
+    CartPosition, OrderPosition, Question, QuestionAnswer, QuestionOption,
+)
 from pretix.presale.forms.checkout import QuestionsForm
 from pretix.presale.views import get_cart
 
@@ -26,7 +29,24 @@ class QuestionsViewMixin:
     def _positions_for_questions(self):
         cart = get_cart(self.request).select_related(
             'addon_to'
-        ).prefetch_related('addons', 'addons__item', 'addons__variation')
+        ).prefetch_related(
+            'addons', 'addons__item', 'addons__variation',
+            Prefetch('answers',
+                     QuestionAnswer.objects.prefetch_related('options'),
+                     to_attr='answerlist'),
+            Prefetch('item__questions',
+                     Question.objects.filter(ask_during_checkin=False).prefetch_related(
+                         Prefetch('options', QuestionOption.objects.prefetch_related(Prefetch(
+                             # This prefetch statement is utter bullshit, but it actually prevents Django from doing
+                             # a lot of queries since ModelChoiceIterator stops trying to be clever once we have
+                             # a prefetch lookup on this query...
+                             'question',
+                             Question.objects.none(),
+                             to_attr='dummy'
+                         )))
+                     ),
+                     to_attr='questions_to_ask')
+        )
         return sorted(list(cart), key=self._keyfunc)
 
     @cached_property