Allow dependencies between questions (#1202)

- [x] data model
- [x] api
- [x] backend editor
- [x] backend validation logic
- [x] frontend display logic
- [x] frontend validation logic
- [x] test checkout step
- [x] test modify order in frontend
- [x] test modify order in backend
- [x] validation tests
- [x] correctly evaluate dependency tree in frontend?
- [x] copy events

src/pretix/presale/checkoutflow.py

@@ -414,10 +414,34 @@ class QuestionsStep(QuestionsViewMixin, CartMixin, TemplateFlowStep):
 
         for cp in self._positions_for_questions:
             answ = {
-                aw.question_id: aw.answer for aw in cp.answerlist
+                aw.question_id: aw for aw in cp.answerlist
             }
+            question_cache = {
+                q.pk: q for q in cp.item.questions_to_ask
+            }
+
+            def question_is_visible(parentid, qval):
+                parentq = question_cache[parentid]
+                if parentq.dependency_question_id and not question_is_visible(parentq.dependency_question_id, parentq.dependency_value):
+                    return False
+                if parentid not in answ:
+                    return False
+                if qval == 'True':
+                    return answ[parentid].answer == 'True'
+                elif qval == 'False':
+                    return answ[parentid].answer == 'False'
+                else:
+                    return qval in [o.identifier for o in answ[parentid].options.all()]
+
+            def question_is_required(q):
+                return (
+                    q.required and
+                    (not q.dependency_question_id or question_is_visible(q.dependency_question_id, q.dependency_value))
+                )
+
             for q in cp.item.questions_to_ask:
-                if q.required and q.id not in answ:
+                print("question", q, "is required", question_is_required(q), "has answer", q.id in answ)
+                if question_is_required(q) and not answ.get(q.id):
                     if warn:
                         messages.warning(request, _('Please fill in answers to all required questions.'))
                     return False

src/pretix/presale/templates/pretixpresale/base.html

@@ -26,6 +26,7 @@
         <script type="text/javascript" src="{% static "bootstrap/js/bootstrap.js" %}"></script>
         <script type="text/javascript" src="{% static "datetimepicker/bootstrap-datetimepicker.js" %}"></script>
         <script type="text/javascript" src="{% static "pretixcontrol/js/jquery.qrcode.min.js" %}"></script>
+        <script type="text/javascript" src="{% static "pretixpresale/js/ui/questions.js" %}"></script>
         <script type="text/javascript" src="{% static "pretixpresale/js/ui/main.js" %}"></script>
         <script type="text/javascript" src="{% static "pretixbase/js/asynctask.js" %}"></script>
         <script type="text/javascript" src="{% static "pretixbase/js/details.js" %}"></script>

src/pretix/presale/templates/pretixpresale/event/checkout_questions.html

@@ -65,7 +65,7 @@
                         </h4>
                     </summary>
                     <div>
-                        <div class="panel-body" data-idx="{{ forloop.counter0 }}">
+                        <div class="panel-body questions-form" data-idx="{{ forloop.counter0 }}">
                             {% if pos.addons.all %}
                                 <div class="form-group">
                                     <label class="col-md-3 control-label">
@@ -97,7 +97,7 @@
                                     {# Add-Ons #}
                                     <legend>+ {{ form.pos.item }}</legend>
                                 {% endif %}
-                                {% bootstrap_form form layout="horizontal" %}
+                                {% bootstrap_form form layout="checkout" %}
                             {% endfor %}
                         </div>
                     </div>

src/pretix/presale/templates/pretixpresale/event/order_modify.html

@@ -53,13 +53,13 @@
                         </h4>
                     </summary>
                     <div id="cp{{ pos.id }}">
-                        <div class="panel-body">
+                        <div class="panel-body questions-form">
                             {% for form in forms %}
                                 {% if form.pos.item != pos.item %}
                                     {# Add-Ons #}
                                     <legend>+ {{ form.pos.item }}</legend>
                                 {% endif %}
-                                {% bootstrap_form form layout="horizontal" %}
+                                {% bootstrap_form form layout="checkout" %}
                             {% endfor %}
                         </div>
                     </div>

src/pretix/presale/views/questions.py

@@ -13,7 +13,7 @@ class QuestionsViewMixin(BaseQuestionsViewMixin):
 
     @cached_property
     def _positions_for_questions(self):
-        qqs = Question.objects.all()
+        qqs = self.request.event.questions.all()
         if self.only_user_visible:
             qqs = qqs.filter(ask_during_checkin=False)
         cart = get_cart(self.request).select_related(
@@ -33,7 +33,7 @@ class QuestionsViewMixin(BaseQuestionsViewMixin):
                              Question.objects.none(),
                              to_attr='dummy'
                          )))
-                     ),
+                     ).select_related('dependency_question'),
                      to_attr='questions_to_ask')
         )
         return sorted(list(cart), key=self._keyfunc)