fix case wrapping

loading settings.CASE_WRAPPER at module import caused a circular import.
Lesson: always use failhard=True with to_function to avoid masking
errors when things get changed.

casexml/apps/case/models.py

@@ -2,8 +2,7 @@
 import re
 from django.core.cache import cache
 from django.conf import settings
-from django.utils.translation import ugettext_noop, ugettext as _
-
+from django.utils.translation import ugettext as _
 from casexml.apps.phone.xml import get_case_element
 from casexml.apps.case.signals import case_post_save
 from casexml.apps.case.util import get_close_case_xml, get_close_referral_xml,\
@@ -37,10 +36,6 @@
 
 INDEX_ID_PARENT = 'parent'
 
-if getattr(settings, 'CASE_WRAPPER', None):
-    CASE_WRAPPER = to_function(getattr(settings, 'CASE_WRAPPER'))
-else:
-    CASE_WRAPPER = None
 
 class CaseBase(SafeSaveDocument):
     """
@@ -273,13 +268,6 @@ class CommCareCase(CaseBase, IndexHoldingMixIn, ComputedDocumentMixin, CaseQuery
 
     server_modified_on = DateTimeProperty()
 
-    def __repr__(self):
-        return u"Case: {id} ({type}: {name})".format(
-            id=self._id,
-            type=self.type,
-            name=self.name,
-        ).encode('utf-8')
-
     def __unicode__(self):
         return "CommCareCase: %s (%s)" % (self.case_id, self.get_id)
 
@@ -300,12 +288,12 @@ def __get_case_id(self):
     def __set_case_id(self, id):
         self._id = id
 
+    case_id = property(__get_case_id, __set_case_id)
+
     def __repr__(self):
         return "%s(name=%r, type=%r, id=%r)" % (
                 self.__class__.__name__, self.name, self.type, self._id)
 
-    case_id = property(__get_case_id, __set_case_id)
-
     @property
     @memoized
     def parent(self):
@@ -397,6 +385,13 @@ def get_lite(cls, id):
 
     @classmethod
     def get_wrap_class(cls, data):
+        try:
+            settings.CASE_WRAPPER
+        except AttributeError:
+            cls._case_wrapper = None
+        else:
+            CASE_WRAPPER = to_function(settings.CASE_WRAPPER, failhard=True)
+
         if CASE_WRAPPER:
             return CASE_WRAPPER(data) or cls
         return cls