Inheritance of models seems to fail when mixing abstract and multi table classes

[zobbo]

Execute the following with the following models table

pi = PlayableItem(funfactor=33,code='PS2',description='Play station 2') 

You'll get the error back

TypeError: 'code' is an invalid keyword argument for this function

models.py is

from django.db import models 
import datetime 

class BaseModel(models.Model): 
    """Abstract class used for some common fields""" 
    created_at = models.DateTimeField(blank=True, default=datetime.datetime.now) 
    modified_at = models.DateTimeField(blank=True, default=datetime.datetime.now) 
    class Meta: 
        abstract = True 

class Item(BaseModel): 
    """Everything in the system - multi table inheritance""" 
    code = models.CharField(blank=True, max_length=15) # A shortname 
    description = models.CharField(blank=True, max_length=50) 

class ValuedItem(Item): 
    """This is an abstract base class for stuff with a value""" 
    value = models.FloatField(default=0.0) 
    class Meta: 
        abstract = True 

class PlayableItem(ValuedItem): 
    """Inheriting from our abstract ValuedItem class""" 
    funfactor = models.IntegerField(blank=True, null=True) # Amount of fun

This is a simplified mockup of something I was trying to do for real with various abstract and multi table classes. I made this test version just to reproduce and report the error. Having enquired in django-users was advised to file a bug report.

This is with checkout from svn - Revision: 7811. psycopg2 backend. python2.5

[Johannes Dollinger]

A minimal example:

class A(Model):
    x = IntegerField()

class B(A):
    y = IntegerField()
    class Meta:
        abstract = True

class C(B):
    z = IntegerField()

The attached patch works for me, but It's probably incomplete. Is diamond inheritance supported (and how)?

[James Bennett]

Could somebody verify whether this is still an issue? I'm punting for now, but if it is still a bug and somebody higher up thinks it's critical enough, we can move back to 1.0.

[Mathijs de Bruin]

Replying to ubernostrum:

Could somebody verify whether this is still an issue? I'm punting for now, but if it is still a bug and somebody higher up thinks it's critical enough, we can move back to 1.0.

Yes, it is still a bug, and it's crawling up my behind right now.

It gives a rather nasty feeling so if you could, please try to fix it. :)

[Mathijs de Bruin]

For convenience, I have adjusted to patch for the current trunk release (r8914) and have confirmed that it is actually working.

[Mathijs de Bruin]

'Naive' patch, updated to r8914.

[Malcolm Tredinnick]

I'll look at this for 1.0. It needs a test case, for a start.

[Malcolm Tredinnick]

(In [8932]) Fixed #7588 -- Inherit fields from concrete ancestor classes via abstract base
classes. Based on a patch from emulbreh.

[Jacob]

Milestone 1.0 deleted