Proxy model inheritance and DoesNotExist exception

[vladimir_webdev]

Code example:

class MyModel(models.Model):
    @classmethod
    def get_current(self):
        self.objects.filter(pk=1).get()

class MyProxyModel(MyModel):
    class Meta:
        proxy = True

try:
    current = MyProxyModel,get_current()
except MyProxyModel.DoesNotExist: # will never be caught, because MyModel.DoesNotExist is actually raised
    pass

To fix this behaviour I simply overwrite exception as this:

MyProxyModel.DoesNotExist = MyModel.DoesNotExist

[Matt McClanahan]

I can't reproduce this in 1.2 or trunk.

>>> from tst.models import MyProxyModel
>>> MyProxyModel.objects.all()
[]
>>> try:
...     MyProxyModel.get_current()
... except MyProxyModel.DoesNotExist:
...     pass
... 
>>> 

[rasca]

Neither do I... closing it as worksforme

[vladimir_webdev]

Sorry, I did not test code, because I thought it does not work in all situations. I got this bug if models are in different packages. My structure:

app/
    __init__.py
    package1/
        __init__.py
        models.py
    package2/
        __init__.py
        models.py

package1/models.py:

from django.db import models

class MyModel(models.Model):
    @classmethod
    def get_current(cls):
        MyModel.objects.get(pk=1000)

package2/models.py:

from app.package1 import models

class MyModel(models.MyModel):
    class Meta:
        proxy = True

view:

from app.package1 import models as package1_models
from app.package2 import models as package2_models

def test(request):
    try:
        current = package1_models.MyModel.get_current()
    except package1_models.MyModel.DoesNotExist: # ok, exception is caught
        pass

    try:
        current = package2_models.MyModel.get_current()
    except package2_models.MyModel.DoesNotExist: # can't caught
        pass

    return http.HttpResponse('ok')

[Matt McClanahan]

I'm afraid I still don't see the problem (other than get_current should call cls.objects.get). It's possible something else in your code is involved. I suggest getting someone to do some further investigating with you, such as on the #django channel on ​irc.freenode.net or the ​django-users mailing list.