Refactor: separate forms from view, improve code style

src/pretix/presale/forms/checkout.py

@@ -0,0 +1,71 @@
+from django import forms
+from django.utils.translation import ugettext_lazy as _
+from pretix.base.models import Question
+
+
+class QuestionsForm(forms.Form):
+    """
+    This form class is responsible for asking order-related questions. This includes
+    the attendee name for admission tickets, if the corresponding setting is enabled,
+    as well as additional questions defined by the organizer.
+    """
+
+    def __init__(self, *args, **kwargs):
+        """
+        Takes two additional keyword arguments:
+
+        :param cartpos: The cart position the form should be for
+        :param event: The event this belongs to
+        """
+        cartpos = kwargs.pop('cartpos', None)
+        orderpos = kwargs.pop('orderpos', None)
+        item = cartpos.item if cartpos else orderpos.item
+        questions = list(item.questions.all())
+        event = kwargs.pop('event')
+
+        super().__init__(*args, **kwargs)
+
+        if item.admission and event.settings.attendee_names_asked:
+            self.fields['attendee_name'] = forms.CharField(
+                max_length=255, required=event.settings.attendee_names_required,
+                label=_('Attendee name'),
+                initial=(cartpos.attendee_name if cartpos else orderpos.attendee_name)
+            )
+
+        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.identity
+            ]
+            if answers:
+                initial = answers[0].answer
+            else:
+                initial = None
+            if q.type == Question.TYPE_BOOLEAN:
+                field = forms.BooleanField(
+                    label=q.question, required=q.required,
+                    initial=initial
+                )
+            elif q.type == Question.TYPE_NUMBER:
+                field = forms.DecimalField(
+                    label=q.question, required=q.required,
+                    initial=initial
+                )
+            elif q.type == Question.TYPE_STRING:
+                field = forms.CharField(
+                    label=q.question, required=q.required,
+                    initial=initial
+                )
+            elif q.type == Question.TYPE_TEXT:
+                field = forms.CharField(
+                    label=q.question, required=q.required,
+                    widget=forms.Textarea,
+                    initial=initial
+                )
+            field.question = q
+            if answers:
+                # Cache the answer object for later use
+                field.answer = answers[0]
+            self.fields['question_%s' % q.identity] = field