Questions at check-in time (#745)

Questions at check-in time

src/pretix/presale/checkoutflow.py

@@ -374,9 +374,9 @@ class QuestionsStep(QuestionsViewMixin, CartMixin, TemplateFlowStep):
 
         for cp in self._positions_for_questions:
             answ = {
-                aw.question_id: aw.answer for aw in cp.answers.all()
+                aw.question_id: aw.answer for aw in cp.answerlist
             }
-            for q in cp.item.questions.all():
+            for q in cp.item.questions_to_ask:
                 if q.required and q.id not in answ:
                     if warn:
                         messages.warning(request, _('Please fill in answers to all required questions.'))

src/pretix/presale/forms/checkout.py

@@ -212,7 +212,7 @@ class QuestionsForm(forms.Form):
         orderpos = self.orderpos = kwargs.pop('orderpos', None)
         pos = cartpos or orderpos
         item = pos.item
-        questions = list(item.questions.all())
+        questions = pos.item.questions_to_ask
         event = kwargs.pop('event')
 
         super().__init__(*args, **kwargs)
@@ -232,11 +232,7 @@ class QuestionsForm(forms.Form):
 
         for q in questions:
             # Do we already have an answer? Provide it as the initial value
-            answers = [
-                a for a
-                in (cartpos.answers.all() if cartpos else orderpos.answers.all())
-                if a.question_id == q.id
-            ]
+            answers = [a for a in pos.answerlist if a.question_id == q.id]
             if answers:
                 initial = answers[0]
             else:
@@ -282,7 +278,7 @@ class QuestionsForm(forms.Form):
                 )
             elif q.type == Question.TYPE_CHOICE:
                 field = forms.ModelChoiceField(
-                    queryset=q.options.all(),
+                    queryset=q.options,
                     label=q.question, required=q.required,
                     help_text=q.help_text,
                     widget=forms.Select,
@@ -291,7 +287,7 @@ class QuestionsForm(forms.Form):
                 )
             elif q.type == Question.TYPE_CHOICE_MULTIPLE:
                 field = forms.ModelMultipleChoiceField(
-                    queryset=q.options.all(),
+                    queryset=q.options,
                     label=q.question, required=q.required,
                     help_text=q.help_text,
                     widget=forms.CheckboxSelectMultiple,

src/pretix/presale/views/__init__.py

@@ -114,7 +114,7 @@ class CartMixin:
             group.has_questions = answers and k[0] != ""
             group.tax_rule = group.item.tax_rule
             if answers:
-                group.cache_answers()
+                group.cache_answers(all=False)
                 group.additional_answers = pos_additional_fields.get(group.pk)
             positions.append(group)
 
@@ -155,6 +155,16 @@ class CartMixin:
         }
 
 
+def cart_exists(request):
+    from pretix.presale.views.cart import get_or_create_cart_id
+
+    if not hasattr(request, '_cart_cache'):
+        return CartPosition.objects.filter(
+            cart_id=get_or_create_cart_id(request), event=request.event
+        ).exists()
+    return bool(request._cart_cache)
+
+
 def get_cart(request):
     from pretix.presale.views.cart import get_or_create_cart_id
 
@@ -166,8 +176,6 @@ def get_cart(request):
         ).select_related(
             'item', 'variation', 'subevent', 'subevent__event', 'subevent__event__organizer',
             'item__tax_rule'
-        ).prefetch_related(
-            'item__questions', 'answers'
         )
     return request._cart_cache
 

src/pretix/presale/views/checkout.py

@@ -10,7 +10,8 @@ from pretix.base.signals import validate_cart
 from pretix.multidomain.urlreverse import eventreverse
 from pretix.presale.checkoutflow import get_checkout_flow
 from pretix.presale.views import (
-    allow_frame_if_namespaced, get_cart, iframe_entry_view_wrapper,
+    allow_frame_if_namespaced, cart_exists, get_cart,
+    iframe_entry_view_wrapper,
 )
 
 
@@ -27,7 +28,7 @@ class CheckoutView(View):
     def dispatch(self, request, *args, **kwargs):
         self.request = request
 
-        if not get_cart(request) and "async_id" not in request.GET:
+        if not cart_exists(request) and "async_id" not in request.GET:
             messages.error(request, _("Your cart is empty"))
             return redirect(self.get_index_url(self.request))
 

src/pretix/presale/views/order.py

@@ -4,7 +4,7 @@ from decimal import Decimal
 
 from django.contrib import messages
 from django.db import transaction
-from django.db.models import Sum
+from django.db.models import Prefetch, Sum
 from django.http import FileResponse, Http404, JsonResponse
 from django.shortcuts import get_object_or_404, redirect, render
 from django.utils.decorators import method_decorator
@@ -14,7 +14,9 @@ from django.utils.translation import ugettext_lazy as _
 from django.views.decorators.clickjacking import xframe_options_exempt
 from django.views.generic import TemplateView, View
 
-from pretix.base.models import CachedTicket, Invoice, Order, OrderPosition
+from pretix.base.models import (
+    CachedTicket, Invoice, Order, OrderPosition, Question, QuestionOption,
+)
 from pretix.base.models.orders import (
     CachedCombinedTicket, InvoiceAddress, OrderFee, QuestionAnswer,
 )
@@ -435,7 +437,21 @@ class OrderModify(EventViewMixin, OrderDetailMixin, QuestionsViewMixin, Template
         return list(self.order.positions.select_related(
             'item', 'variation'
         ).prefetch_related(
-            'variation', 'item__questions', 'answers'
+            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')
         ))
 
     @cached_property

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