Add identifier field to questions

src/pretix/base/migrations/0085_auto_20180312_1119.py

@@ -0,0 +1,59 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.11 on 2018-03-12 11:19
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+from django.utils.crypto import get_random_string
+
+
+def set_identifiers(apps, schema_editor):
+    Question = apps.get_model('pretixbase', 'Question')
+    QuestionOption = apps.get_model('pretixbase', 'QuestionOption')
+
+    for q in Question.objects.select_related('event'):
+        if not q.identifier:
+            charset = list('ABCDEFGHJKLMNPQRSTUVWXYZ3789')
+            while True:
+                code = get_random_string(length=8, allowed_chars=charset)
+                if not Question.objects.filter(event=q.event, identifier=code).exists():
+                    q.identifier = code
+                    q.save()
+                    break
+
+    for q in QuestionOption.objects.select_related('question', 'question__event'):
+        if not q.identifier:
+            charset = list('ABCDEFGHJKLMNPQRSTUVWXYZ3789')
+            while True:
+                code = get_random_string(length=8, allowed_chars=charset)
+                if not QuestionOption.objects.filter(question__event=q.question.event, identifier=code).exists():
+                    q.identifier = code
+                    q.save()
+                    break
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('pretixbase', '0084_questionoption_position'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='question',
+            name='identifier',
+            field=models.CharField(default='', max_length=190),
+            preserve_default=False,
+        ),
+        migrations.AddField(
+            model_name='questionoption',
+            name='identifier',
+            field=models.CharField(default='', max_length=190),
+            preserve_default=False,
+        ),
+        migrations.AlterField(
+            model_name='user',
+            name='locale',
+            field=models.CharField(choices=[('en', 'English'), ('de', 'German'), ('de-informal', 'German (informal)'), ('nl', 'Dutch'), ('da', 'Danish'), ('pt-br', 'Portuguese (Brazil)')], default='en', max_length=50, verbose_name='Language'),
+        ),
+        migrations.RunPython(set_identifiers, migrations.RunPython.noop)
+    ]

src/pretix/base/models/items.py

@@ -11,6 +11,7 @@ from django.core.exceptions import ValidationError
 from django.db import models
 from django.db.models import F, Func, Q, Sum
 from django.utils import formats
+from django.utils.crypto import get_random_string
 from django.utils.functional import cached_property
 from django.utils.timezone import is_naive, make_aware, now
 from django.utils.translation import pgettext_lazy, ugettext_lazy as _
@@ -630,6 +631,8 @@ class Question(LoggedModel):
     :param items: A set of ``Items`` objects that this question should be applied to
     :param ask_during_checkin: Whether to ask this question during check-in instead of during check-out.
     :type ask_during_checkin: bool
+    :param identifier: An arbitrary, internal identifier
+    :type identifier: str
     """
     TYPE_NUMBER = "N"
     TYPE_STRING = "S"
@@ -661,6 +664,12 @@ class Question(LoggedModel):
     question = I18nTextField(
         verbose_name=_("Question")
     )
+    identifier = models.CharField(
+        max_length=190,
+        verbose_name=_("Internal identifier"),
+        help_text=_('You can enter any value here to make it easier to match the data with other sources. If you do '
+                    'not input one, we will generate one automatically.')
+    )
     help_text = I18nTextField(
         verbose_name=_("Help text"),
         help_text=_("If the question needs to be explained or clarified, do it here!"),
@@ -706,7 +715,18 @@ class Question(LoggedModel):
         if self.event:
             self.event.cache.clear()
 
+    def clean_identifier(self, code):
+        if Question.objects.filter(event=self.event, identifier=code).exclude(pk=self.pk).exists():
+            raise ValidationError(_('This identifier is already used for a different question.'))
+
     def save(self, *args, **kwargs):
+        if not self.identifier:
+            charset = list('ABCDEFGHJKLMNPQRSTUVWXYZ3789')
+            while True:
+                code = get_random_string(length=8, allowed_chars=charset)
+                if not Question.objects.filter(event=self.event, identifier=code).exists():
+                    self.identifier = code
+                    break
         super().save(*args, **kwargs)
         if self.event:
             self.event.cache.clear()
@@ -779,12 +799,23 @@ class Question(LoggedModel):
 
 class QuestionOption(models.Model):
     question = models.ForeignKey('Question', related_name='options')
+    identifier = models.CharField(max_length=190)
     answer = I18nCharField(verbose_name=_('Answer'))
     position = models.IntegerField(default=0)
 
     def __str__(self):
         return str(self.answer)
 
+    def save(self, *args, **kwargs):
+        if not self.identifier:
+            charset = list('ABCDEFGHJKLMNPQRSTUVWXYZ3789')
+            while True:
+                code = get_random_string(length=8, allowed_chars=charset)
+                if not QuestionOption.objects.filter(question__event=self.question.event, identifier=code).exists():
+                    self.identifier = code
+                    break
+        super().save(*args, **kwargs)
+
     class Meta:
         verbose_name = _("Question option")
         verbose_name_plural = _("Question options")