Refactored checkout steps

src/pretix/presale/views/questions.py

@@ -0,0 +1,61 @@
+from django.utils.functional import cached_property
+
+from pretix.base.models import CartPosition, OrderPosition, QuestionAnswer
+from pretix.presale.forms.checkout import QuestionsForm
+
+
+class QuestionsViewMixin:
+    @cached_property
+    def forms(self):
+        """
+        A list of forms with one form for each cart cart position that has questions
+        the user can answer. All forms have a custom prefix, so that they can all be
+        submitted at once.
+        """
+        formlist = []
+        for cr in self.positions:
+            cartpos = cr if isinstance(cr, CartPosition) else None
+            orderpos = cr if isinstance(cr, OrderPosition) else None
+            form = QuestionsForm(event=self.request.event,
+                                 prefix=cr.identity,
+                                 cartpos=cartpos,
+                                 orderpos=orderpos,
+                                 data=(self.request.POST if self.request.method == 'POST' else None))
+            form.pos = cartpos or orderpos
+            if len(form.fields) > 0:
+                formlist.append(form)
+        return formlist
+
+    def save(self):
+        failed = False
+        for form in self.forms:
+            # Every form represents a CartPosition or OrderPosition with questions attached
+            if not form.is_valid():
+                failed = True
+            else:
+                # This form was correctly filled, so we store the data as
+                # answers to the questions / in the CartPosition object
+                for k, v in form.cleaned_data.items():
+                    if k == 'attendee_name':
+                        form.pos = form.pos.clone()
+                        form.pos.attendee_name = v if v != '' else None
+                        form.pos.save()
+                    elif k.startswith('question_') and v is not None:
+                        field = form.fields[k]
+                        if hasattr(field, 'answer'):
+                            # We already have a cached answer object, so we don't
+                            # have to create a new one
+                            if v == '':
+                                field.answer.delete()
+                            else:
+                                field.answer = field.answer.clone()
+                                field.answer.answer = v
+                                field.answer.save()
+                        elif v != '':
+                            QuestionAnswer.objects.create(
+                                cartposition=(form.pos if isinstance(form.pos, CartPosition) else None),
+                                orderposition=(form.pos if isinstance(form.pos, OrderPosition) else None),
+                                question=field.question,
+                                answer=v
+                            )
+        return not failed