PolyModels can't be retrieved from bdbdatstorage

[zutesmog]

I have run into a problem now though with PolyModels
I can create them fine, however if I fetch the entity I get the
following error.

c1=psc.models.Course.all().fetch(1)[0]
c2=psc.models.Campus.all().fetch(1)[0]
c2

c1

cc = psc.models.CourseCampus(key_name="abc")
cc.src_id = str(c1.key())
cc.target_id = str(c2.key())
cc.src = c1
cc.target = c2
cc.put()
datastore_types.Key.from_path(u'Reference', u'abc',_app_id_namespace=u'psc-dev1')
xx = psc.models.CourseCampus.get_by_key_name("abc")
Traceback (most recent call last):
File "", line 1, in
File "/home/timh/google_appengine_1.2.4/google/appengine/ext/db/
init.py", line 900, in get_by_key_name
return get(*keys)
File "/home/timh/google_appengine_1.2.4/google/appengine/ext/db/
init.py", line 1105, in get
model = cls1.from_entity(entity)
File "/home/timh/google_appengine_1.2.4/google/appengine/ext/db/
polymodel.py", line 310, in from_entity
raise db.KindError('No implementation for class '%s'' % key)
TypeError: not all arguments converted during string formatting

Exactly the same code works fine with standard SDK datastore

[zutesmog]

The key and _class_map seem to have reversed keys .

304 if (_CLASS_KEY_PROPERTY in entity and
305 tuple(entity[_CLASS_KEY_PROPERTY]) != cls.class_key()):
306 key = tuple(entity[_CLASS_KEY_PROPERTY])
307 import pdb
308 pdb.set_trace()
309 -> try:
310 poly_class = _class_map[key]
311 except KeyError:
312 raise db.KindError('No implementation for class '%s'' % key)
313 return poly_class.from_entity(entity)
314 return super(PolyModel, cls).from_entity(entity)

(Pdb) key

(u'CourseCampus', u'Reference')

(Pdb) _class_map

{('Reference', 'CourseCampus'): <class 'psc.models.coursecampus.CourseCampus'>, ('Reference', 'UnitListUnitOfStudy'): <class 'psc.models.unitlistunitofstudy.UnitListUnitOfStudy'>, ('Reference',): <class 'psc.models.reference.Reference'>, ('Reference', 'Classification'): <class 'psc.models.classification.Classification'>}

[zutesmog]

Ok further investigation shows that the class attribute of the raw entity has the values order reversed when saved in bdbdatastore vs standard sdk. But on the entities creation before being saved the class attributes values are in the correct order.

x1 = psc.models.Course.all().get()
x2 = psc.models.Campus.all().get()
x3 = psc.models.CourseCampus(key_name="x1x2")
psc.models.CourseCampus.class_key()
('Reference', 'CourseCampus')

Later on retrieval of that record from bdbdatastore has the values reversed.

zz = psc.models.CourseCampus.get_by_key_name("x1x2")

/home/timh/google_appengine/google/appengine/ext/db/polymodel.py(309)from_entity()

-> try:

(Pdb) p key

(u'CourseCampus', u'Reference')

(Pdb) p entity

{u'src': datastore_types.Key.from_path(u'Course', u"(97868, u'0386')", _app_id_namespace=u'psc-dev1'), u'src_id': None, u'target': datastore_types.Key.from_path(u'Campus', u"(u'1304587',)", _app_id_namespace=u'psc-dev1'), u'created': datetime.datetime(2009, 9, 3, 0, 7, 46, 720900), u'reference_type': None, u'target_id': None, u'modified': datetime.datetime(2009, 9, 3, 0, 8, 38, 390370), u'class': [u'CourseCampus', u'Reference']}