Assigning the super class of a Proxy class to a ForeignKey fails.

[David Novakovic]

from django.db import models
from proj.myapp.models import ProxyClass


class NewClass(models.Model):
    proxy = models.ForeignKey(ProxyClass,related_name="newclass",unique=True)

Failure stacktrace on save():

>> n.proxy = p  # p is actually an instance of SuperClass
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "...lib/common/django/db/models/fields/related.py", line 272, in __set__
    self.field.name, self.field.rel.to._meta.object_name))
ValueError: Cannot assign "SuperClass": "NewClass.proxy" must be a "Proxy" instance.

First ticket for me, so let me know if I can provide more info.

Cheers

[David Novakovic]

Sorry - that should be on assignment, not save.

[David Novakovic]

To clarify a few more details:

• The model validates fine, tables are created with syncdb etc.
• The SuperClass is a fully fledged db.models.Model.
• Proxy is a proxy class that extends SuperClass but has no table in the DB.

class Proxy(SuperClass):
    def proxy_behaviour(self):
        pass

    class Meta:
        proxy = True

Hope that helps a bit more...

[Alex Gaynor]

This is perfectly consistant behavior, if you expect a specific class (proxy or otherwise) and you assign a superclass of it it will not be accepted.