add simple survey support

generic/models.py

@@ -716,6 +716,23 @@ class ExamOrCollectionGenericBase(models.Model, AuthorMixin):
 
     exam_open_access = models.BooleanField(default=False, help_text="Set to true if you want any registered user to be able to take the exam.")
 
+    pre_survey = models.ForeignKey(
+        "survey.Survey",
+        on_delete=models.SET_NULL,
+        null=True,
+        blank=True,
+        related_name="%(app_label)s_%(class)s_pre_surveys",
+        help_text="Survey to be filled out BEFORE taking this collection/exam."
+    )
+    post_survey = models.ForeignKey(
+        "survey.Survey",
+        on_delete=models.SET_NULL,
+        null=True,
+        blank=True,
+        related_name="%(app_label)s_%(class)s_post_surveys",
+        help_text="Survey to be filled out AFTER completing this collection/exam."
+    )
+
     class Meta:
         abstract = True