Remove circular dependencies that connect student.models and django_comment_client

common/djangoapps/student/models.py

@@ -262,16 +262,6 @@ class CourseEnrollment(models.Model):
         return "[CourseEnrollment] %s: %s (%s)" % (self.user, self.course_id, self.created)
 
 
-@receiver(post_save, sender=CourseEnrollment)
-def assign_default_role(sender, instance, **kwargs):
-    if instance.user.is_staff:
-        role = Role.objects.get_or_create(course_id=instance.course_id, name="Moderator")[0]
-    else:
-        role = Role.objects.get_or_create(course_id=instance.course_id, name="Student")[0]
-
-    logging.info("assign_default_role: adding %s as %s" % (instance.user, role))
-    instance.user.roles.add(role)
-
 #cache_relation(User.profile)
 
 #### Helper methods for use from python manage.py shell.

lms/djangoapps/django_comment_client/models.py

@@ -2,6 +2,10 @@ import logging
 
 from django.db import models
 from django.contrib.auth.models import User
+from django.dispatch import receiver
+from django.db.models.signals import post_save
+
+from student.models import CourseEnrollment
 
 from courseware.courses import get_course_by_id
 
@@ -45,3 +49,14 @@ class Permission(models.Model):
 
     def __unicode__(self):
         return self.name
+
+
+@receiver(post_save, sender=CourseEnrollment)
+def assign_default_role(sender, instance, **kwargs):
+    if instance.user.is_staff:
+        role = Role.objects.get_or_create(course_id=instance.course_id, name="Moderator")[0]
+    else:
+        role = Role.objects.get_or_create(course_id=instance.course_id, name="Student")[0]
+
+    logging.info("assign_default_role: adding %s as %s" % (instance.user, role))
+    instance.user.roles.add(role)