API: Allow to answer file upload questions during ticket redemption

src/pretix/api/views/checkin.py

@@ -22,7 +22,7 @@ from pretix.api.views import RichOrderingFilter
 from pretix.api.views.order import OrderPositionFilter
 from pretix.base.i18n import language
 from pretix.base.models import (
-    Checkin, CheckinList, Event, Order, OrderPosition,
+    CachedFile, Checkin, CheckinList, Event, Order, OrderPosition, Question,
 )
 from pretix.base.services.checkin import (
     CheckInError, RequiredQuestionsError, perform_checkin,
@@ -302,7 +302,10 @@ class CheckinListPositionViewSet(viewsets.ReadOnlyModelViewSet):
             for q in op.item.questions.filter(ask_during_checkin=True):
                 if str(q.pk) in aws:
                     try:
-                        given_answers[q] = q.clean_answer(aws[str(q.pk)])
+                        if q.type == Question.TYPE_FILE:
+                            given_answers[q] = self._handle_file_upload(aws[str(q.pk)])
+                        else:
+                            given_answers[q] = q.clean_answer(aws[str(q.pk)])
                     except ValidationError:
                         pass
 
@@ -352,3 +355,25 @@ class CheckinListPositionViewSet(viewsets.ReadOnlyModelViewSet):
                 'require_attention': op.item.checkin_attention or op.order.checkin_attention,
                 'position': CheckinListOrderPositionSerializer(op, context=self.get_serializer_context()).data
             }, status=201)
+
+    def _handle_file_upload(self, data):
+        try:
+            cf = CachedFile.objects.get(
+                session_key=f'api-upload-{str(type(self.request.user or self.request.auth))}-{(self.request.user or self.request.auth).pk}',
+                file__isnull=False,
+                pk=data[len("file:"):],
+            )
+        except (ValidationError, IndexError):  # invalid uuid
+            raise ValidationError('The submitted file ID "{fid}" was not found.'.format(fid=data))
+        except CachedFile.DoesNotExist:
+            raise ValidationError('The submitted file ID "{fid}" was not found.'.format(fid=data))
+
+        allowed_types = (
+            'image/png', 'image/jpeg', 'image/gif', 'application/pdf'
+        )
+        if cf.type not in allowed_types:
+            raise ValidationError('The submitted file "{fid}" has a file type that is not allowed in this field.'.format(fid=data))
+        if cf.file.size > 10 * 1024 * 1024:
+            raise ValidationError('The submitted file "{fid}" is too large to be used in this field.'.format(fid=data))
+
+        return cf.file

src/pretix/base/models/items.py

@@ -1026,7 +1026,7 @@ class Question(LoggedModel):
         (TYPE_PHONENUMBER, _("Phone number")),
     )
     UNLOCALIZED_TYPES = [TYPE_DATE, TYPE_TIME, TYPE_DATETIME]
-    ASK_DURING_CHECKIN_UNSUPPORTED = [TYPE_FILE, TYPE_PHONENUMBER]
+    ASK_DURING_CHECKIN_UNSUPPORTED = [TYPE_PHONENUMBER]
 
     event = models.ForeignKey(
         Event,
@@ -1069,6 +1069,7 @@ class Question(LoggedModel):
     )
     ask_during_checkin = models.BooleanField(
         verbose_name=_('Ask during check-in instead of in the ticket buying process'),
+        help_text=_('Not supported by all check-in apps for all question types.'),
         default=False
     )
     hidden = models.BooleanField(

src/pretix/base/services/checkin.py

@@ -1,6 +1,7 @@
 from datetime import timedelta
 
 import dateutil
+from django.core.files import File
 from django.db import transaction
 from django.db.models.functions import TruncDate
 from django.dispatch import receiver
@@ -125,6 +126,14 @@ def _save_answers(op, answers, given_answers):
             else:
                 qa = op.answers.create(question=q, answer=", ".join([str(o) for o in a]))
             qa.options.add(*a)
+        elif isinstance(a, File):
+            if q in answers:
+                qa = answers[q]
+            else:
+                qa = op.answers.create(question=q, answer=str(a))
+            qa.file.save(a.name, a, save=False)
+            qa.answer = 'file://' + qa.file.name
+            qa.save()
         else:
             if q in answers:
                 qa = answers[q]

src/tests/api/test_checkin.py

@@ -7,6 +7,7 @@ from unittest import mock
 from urllib.parse import quote as urlquote
 
 import pytest
+from django.core.files.base import ContentFile
 from django.utils.timezone import now
 from django_countries.fields import Country
 from django_scopes import scopes_disabled
@@ -995,3 +996,46 @@ def test_question_multiple_choice(token_client, organizer, clist, event, order,
     with scopes_disabled():
         assert order.positions.first().answers.get(question=question[0]).answer == 'M, L'
         assert set(order.positions.first().answers.get(question=question[0]).options.all()) == {question[1], question[2]}
+
+
+@pytest.mark.django_db
+def test_question_upload(token_client, organizer, clist, event, order, question):
+    r = token_client.post(
+        '/api/v1/upload',
+        data={
+            'media_type': 'image/png',
+            'file': ContentFile('file.png', 'invalid png content')
+        },
+        format='upload',
+        HTTP_CONTENT_DISPOSITION='attachment; filename="file.png"',
+    )
+    assert r.status_code == 201
+    file_id_png = r.data['id']
+
+    with scopes_disabled():
+        p = order.positions.first()
+    question[0].type = 'F'
+    question[0].save()
+
+    resp = token_client.post('/api/v1/organizers/{}/events/{}/checkinlists/{}/positions/{}/redeem/'.format(
+        organizer.slug, event.slug, clist.pk, p.pk
+    ), {}, format='json')
+    assert resp.status_code == 400
+    assert resp.data['status'] == 'incomplete'
+    with scopes_disabled():
+        assert resp.data['questions'] == [QuestionSerializer(question[0]).data]
+
+    resp = token_client.post('/api/v1/organizers/{}/events/{}/checkinlists/{}/positions/{}/redeem/'.format(
+        organizer.slug, event.slug, clist.pk, p.pk
+    ), {'answers': {question[0].pk: "invalid"}}, format='json')
+    assert resp.status_code == 400
+    assert resp.data['status'] == 'incomplete'
+
+    resp = token_client.post('/api/v1/organizers/{}/events/{}/checkinlists/{}/positions/{}/redeem/'.format(
+        organizer.slug, event.slug, clist.pk, p.pk
+    ), {'answers': {question[0].pk: file_id_png}}, format='json')
+    assert resp.status_code == 201
+    assert resp.data['status'] == 'ok'
+    with scopes_disabled():
+        assert order.positions.first().answers.get(question=question[0]).answer.startswith('file://')
+        assert order.positions.first().answers.get(question=question[0]).file