Handle Proxy Model Permissions (Django bug #11154)

[ctxis]

Handle Proxy Model Permissions (Django bug #11154)

[lefterisnik]

Hi @ciarancourtney,

OK, I see your problem.

You could try to trigger the signal manually like this:

# -*- coding: utf-8 -*-

"""Add permissions for proxy model.
This is needed because of the bug https://code.djangoproject.com/ticket/11154
in Django (as of 1.6, it's not fixed).
When a permission is created for a proxy model, it actually creates if for it's
base model app_label (eg: for "article" instead of "about", for the About proxy
model).
What we need, however, is that the permission be created for the proxy model
itself, in order to have the proper entries displayed in the admin.
"""

import sys

from django.contrib.auth.management import _get_all_permissions
from django.contrib.auth.models import Permission
from django.contrib.contenttypes.models import ContentType
from django.core.management.base import BaseCommand
from django.apps import apps
from admin_view_permission.apps import update_permissions


class Command(BaseCommand):
    help = "Fix permissions for proxy models."

    def handle(self, *args, **options):
        update_permissions(
            apps.get_app_config('app'),  # where app is the app of the management command
            apps.get_app_config('app'),
            verbosity=1,
            interactive=True,
            using='default',
        )

        for model in apps.get_models():
            opts = model._meta
            ctype, created = ContentType.objects.get_or_create(
                app_label=opts.app_label,
                model=opts.object_name.lower())

            for codename, name in _get_all_permissions(opts):
                p, created = Permission.objects.get_or_create(
                    codename=codename,
                    content_type=ctype,
                    defaults={'name': name})
                if created:
                    sys.stdout.write('Adding permission {}\n'.format(p))

Although, the admin_view_permission seems not to work correctly with the proxy models (doesn't return any field to the view). You could try it too. I will have a better look on this tomorrow.

I hope this could help you.

Thanks,
Lefteris

[ciarancourtney]

Thanks, I got around the issue by manually creating the admin-view-permission in my proxy meta class.

    permissions = (
        ('view_myuser', "Can view My User"),
    )

Then I added a RunPython Data Migration to the autogenerated migration script:

# -*- coding: utf-8 -*-
# Generated by Django 1.11.1 on 2017-05-31 16:17
from __future__ import unicode_literals

from django.db import migrations
from django.contrib.auth.management import _get_all_permissions
from django.contrib.auth.models import Permission
from django.contrib.contenttypes.models import ContentType


# forward func
def add_myuser_proxy_permissions(apps, schema_editor):
    app_config = apps.get_app_config('profiles')
    model = app_config.get_model('MyUser')
    opts = model._meta
    ctype, created = ContentType.objects.get_or_create(
        app_label=opts.app_label,
        model=opts.object_name.lower(),
    )

    for codename, name in _get_all_permissions(opts):
        p, created = Permission.objects.get_or_create(
            codename=codename,
            content_type=ctype,
            defaults={'name': f'{name} (Proxy)'})
        if created:
            print(f'Adding permission: {p}')


# reverse func
def delete_myuser_proxy_permissions(apps, schema_editor):
    permissions = Permission.objects.filter(codename__icontains='myuser')
    permissions.delete()


class Migration(migrations.Migration):

    dependencies = [
        ('profiles', '0015_auto_20170531_0922'),
    ]

    operations = [
        migrations.AlterModelOptions(
            name='myuser',
            options={'permissions': (('view_myuser', 'Can view My User'),), 'verbose_name': 'My User', 'verbose_name_plural': 'My Users'},
        ),
        migrations.RunPython(add_myuser_proxy_permissions, delete_myuser_proxy_permissions),
    ]

When a user with view_myuser (proxy) and view_profile visits the change page of a MyUser, the Django User fields are editable, but this is probably a quirk of the builtin UserAdmin form, The Save buttons do not appear, as expected

[lefterisnik]

Hi @ciarancourtney,

Which Django version do you use? I am testing the behaviour on Django 1.11 and it doesn't return any fields because the code tries to get the local fields and the proxy model doesn't contain any local fields (I will push a fix to master shortly).

Thanks,
Lefteris

[ciarancourtney]

I'm on the latest, Django 1.11.2 and DAVP 0.9. Perhaps its because I'm subclassing the UserCreationForm and UserChangeForm

[lefterisnik]

Hi @ciarancourtney,

I am going to close this ticket. I've added the management command(which fixes the permission for the proxy models) to the package and also I've fixed the get_readonly_fields to return the appropriate fields.

Thanks,
Lefteris