How do I extend the Django Group model? - python

Is there a way to extend the built-in Django Group object to add additional attributes similar to the way you can extend a user object? With a user object, you can do the following:
class UserProfile(models.Model):
user = models.OneToOneField(User)
and add the following to the settings.py file
AUTH_PROFILE_MODULE = 'app.UserProfile'
which gets you:
profile = User.objects.get(id=1).get_profile()
Is there any equivalent to this approach for extending a group? If not, is there an alternative approach I can take?

If you simply subclass the Group object then by default it will create a new database table and the admin site won't pick up any new fields.
You need to inject new fields into the existing Group:
if not hasattr(Group, 'parent'):
field = models.ForeignKey(Group, blank=True, null=True, related_name='children')
field.contribute_to_class(Group, 'parent')
To add methods to the Group, subclass but tag the model as proxy:
class MyGroup(Group):
class Meta:
proxy = True
def myFunction(self):
return True

You can create a model that subclasses Group, add your own fields, and use a Model Manager to return any custom querysets you need. Here's a truncated example showing how I extended Group to represent Families associated with a school:
from django.contrib.auth.models import Group, User
class FamilyManager(models.Manager):
"""
Lets us do querysets limited to families that have
currently enrolled students, e.g.:
Family.has_students.all()
"""
def get_query_set(self):
return super(FamilyManager, self).get_query_set().filter(student__enrolled=True).distinct()
class Family(Group):
notes = models.TextField(blank=True)
# Two managers for this model - the first is default
# (so all families appear in the admin).
# The second is only invoked when we call
# Family.has_students.all()
objects = models.Manager()
has_students = FamilyManager()
class Meta:
verbose_name_plural = "Families"
ordering = ['name']
def __unicode__(self):
return self.name

I managed to use migrations with #Semprini aswer.
So i needed to create a company related field in my groups related field, so in my models i did this:
if not hasattr(Group, 'company'):
field = models.ForeignKey(Company, on_delete=models.DO_NOTHING, null=True)
field.contribute_to_class(Group, 'company')
class Group(Group):
class Meta:
proxy = True
Then i run manage.py makemigrations. This created 2 files. One with dependencies on the other, but the first one belonging to the auth app was created inside my virtual enviroment. The files look like this:
# Generated by Django 2.2.5 on 2019-10-08 16:00
from django.db import migrations, models
import django.db.models.deletion
class Migration(migrations.Migration):
dependencies = [
('myapp', '0013_guestuser_permissions_20190919_1715'),
('auth', '0011_update_proxy_permissions'),
]
operations = [
migrations.AddField(
model_name='group',
name='company',
field=models.ForeignKey(
null=True, on_delete=django.db.models.deletion.DO_NOTHING, to='myapp.Company'),
),
]
The second one created in myapp migrations folder look like this:
# Generated by Django 2.2.5 on 2019-10-08 16:00
import django.contrib.auth.models
from django.db import migrations
class Migration(migrations.Migration):
dependencies = [
('auth', '0012_group_company_20191008'),
('myapp', '0013_guestuser_permissions_20190919_1715'),
]
operations = [
migrations.CreateModel(
name='Group',
fields=[
],
options={
'proxy': True,
'indexes': [],
'constraints': [],
},
bases=('auth.group',),
managers=[
('objects', django.contrib.auth.models.GroupManager()),
],
),
]
So the solution was to move the file created in my virtualenv to myapp migrations folder, before the other one generated with makemigrations, but since the migration is applied to the auth app instead of myapp i have to implement a workaround in the file. So the final file now is:
# Generated by Django 2.2.5 on 2019-10-08 16:00
from django.db import migrations, models
import django.db.models.deletion
class Migration(migrations.Migration):
dependencies = [
('myapp', '0013_guestuser_permissions_20190919_1715'),
('auth', '0011_update_proxy_permissions'),
]
operations = [
migrations.AddField(
model_name='group',
name='company',
field=models.ForeignKey(
null=True, on_delete=django.db.models.deletion.DO_NOTHING, to='myapp.Company'),
),
]
def mutate_state(self, project_state, preserve=True):
"""
This is a workaround that allows to store ``auth``
migration outside the directory it should be stored.
"""
app_label = self.app_label
self.app_label = 'auth'
state = super(Migration, self).mutate_state(project_state, preserve)
self.app_label = app_label
return state
def apply(self, project_state, schema_editor, collect_sql=False):
"""
Same workaround as described in ``mutate_state`` method.
"""
app_label = self.app_label
self.app_label = 'auth'
state = super(Migration, self).apply(project_state, schema_editor, collect_sql)
self.app_label = app_label
return state
The mutate an apply methods allow you to migrate to the auth app from myapp migrations.
In the second file i just change the dependencie to depend on the newly file created:
# Generated by Django 2.2.5 on 2019-10-08 16:00
import django.contrib.auth.models
from django.db import migrations
class Migration(migrations.Migration):
dependencies = [
('myapp', '0014_group_company_20191008'),
('myapp', '0013_guestuser_permissions_20190919_1715'),
]
operations = [
migrations.CreateModel(
name='Group',
fields=[
],
options={
'proxy': True,
'indexes': [],
'constraints': [],
},
bases=('auth.group',),
managers=[
('objects', django.contrib.auth.models.GroupManager()),
],
),
]

For me worked solution based on:
https://docs.djangoproject.com/pl/1.11/topics/auth/customizing/#extending-user
Let me explain what I did with Groups extending default model with email alias:
First of all I created my own django application let name it
python manage.py startapp auth_custom
Code section:
In auth_custom/models.py I created object CustomGroup
from django.contrib.auth.models import Group
from django.db import models
class CustomGroup(models.Model):
"""
Overwrites original Django Group.
"""
def __str__(self):
return "{}".format(self.group.name)
group = models.OneToOneField('auth.Group', unique=True)
email_alias = models.EmailField(max_length=70, blank=True, default="")
In auth_custom/admin.py:
from django.contrib.auth.admin import GroupAdmin as BaseGroupAdmin
from django.contrib.auth.models import Group
class GroupInline(admin.StackedInline):
model = CustomGroup
can_delete = False
verbose_name_plural = 'custom groups'
class GroupAdmin(BaseGroupAdmin):
inlines = (GroupInline, )
# Re-register GroupAdmin
admin.site.unregister(Group)
admin.site.register(Group, GroupAdmin)
After making migrations I have such result in Django Admin view.
Custom Group in Django Admin
In order to access this custom field you must type:
from django.contrib.auth.models import Group
group = Group.objects.get(name="Admins") # example name
email_alias = group.customgroup.email_alias
If any mistakes please notify me, I'll correct this answere.

Related

Add group and permission to group with migration django

i have problem with groups and permission in django.
I want to create a group of users and admin.
In django panel admin i see permission which i need:
app | user | Can add user
app | user | Can change user
app | user | Can delete user
app | user | Can view user
I need create group "user" and "admin" then add perm to user "Can view user" and to admin all this perms and this is need to do with migration.
My already code i suposed is totally stupid
# Generated by Django 4.0.3 on 2022-09-11 10:33
from django.db import migrations, transaction
from django.contrib.auth.models import Group, Permission
def add_group_permissions(a,b):
group, created = Group.objects.get_or_create(name='user')
try:
with transaction.atomic():
group.permissions.add(can_view_user)
group.save()
except InterruptedError:
group.delete()
class Migration(migrations.Migration):
dependencies = [
('app', '0001_initial'),
]
operations = [
migrations.RunPython(add_group_permissions),
]
If anyone can help, i need that.
I have some examples of custom permissions.
In your models.py try this below your class:
class Meta:
permissions = [
("access_app", "Can access the budget app"), # access for all budget app
(
"level_2",
"Can access the budget app - level 2",
), # access to EyePlan model + hr
(
"level_3",
"Can access the budget app - level 3",
), # access to EyePlan model only
]
In your views.py:
class BudgetMixin(PermissionRequiredMixin):
permission_required = "budget.access_app"
Try to customize this code for your own requirements, hope it gonna help you.
Ok, i have that now in models.py:
from django.db import models
from django.contrib.auth.models import AbstractUser
class CustomUser(AbstractUser):
username = models.EmailField(unique=True)
name = models.CharField(max_length=64)
last_name = models.CharField(max_length=64)
phone_number = models.CharField(max_length=9, unique=True)
USERNAME_FIELD = 'username'
REQUIRED_FIELDS = []
class Meta:
permissions = [
("can_add_user", "Can add user"),
("can_change_user", "Can change user"),
("can_delete_user", "Can delete user"),
("can_view_user", "Can view user"),
]
But how to create now group "user" wtih permission can_view_user and "admin" with: can_add_user; can_change_user; can_delete_user; can_view_user.

Field defines a relation with the model 'auth.User', which has been swapped out.(fields.E301)

I'm getting this error.
ERRORS: subscriptions.StripeCustomer.user: (fields.E301) Field defines
a relation with the model 'auth.User', which has been swapped out.
HINT: Update the relation to point at 'settings.AUTH_USER_MODEL'.
I'm trying to configure Django Stripe Subscriptions following this manual https://testdriven.io/blog/django-stripe-subscriptions/
My models.py
from django.contrib.auth.models import User
from django.db import models
class StripeCustomer(models.Model):
user = models.OneToOneField(to=User, on_delete=models.CASCADE)
stripeCustomerId = models.CharField(max_length=255)
stripeSubscriptionId = models.CharField(max_length=255)
def __str__(self):
return self.user.username
My admin.py
from django.contrib import admin
from subscriptions.models import StripeCustomer
admin.site.register(StripeCustomer)
My settings.py
#used for django-allauth
AUTH_USER_MODEL = 'accounts.CustomUser'
DEFAULT_AUTO_FIELD='django.db.models.AutoField'
SITE_ID = 1
AUTHENTICATION_BACKENDS = (
'allauth.account.auth_backends.AuthenticationBackend',
'django.contrib.auth.backends.ModelBackend',
)
EMAIL_BACKEND = 'django.core.mail.backends.console.EmailBackend'
ACCOUNT_EMAIL_VERIFICATION = "none"
accounts/models.py
from django.contrib.auth.models import AbstractUser
class CustomUser(AbstractUser):
class Meta:
verbose_name_plural = 'CustomUser'
After setting above, I executed "python manage.py makemigrations && python manage.py migrate" then the error occurred.
I just mentioned the above settings in this question but still if more code is required then tell me I'll update my question with that information. Thank you
You have your OneToOneField pointing to the User model from django.contrib.auth when in fact you are using a custom user model CustomUser, hence you get the error. Generally if one wants to have a foreign key or any related field with the user model one should point it to settings.AUTH_USER_MODEL as described in the Referencing the User model [Django docs] so that such issues can be prevented easily. Hence change your StripeCustomer model like so:
from django.conf import settings
from django.db import models
class StripeCustomer(models.Model):
user = models.OneToOneField(to=settings.AUTH_USER_MODEL, on_delete=models.CASCADE)
stripeCustomerId = models.CharField(max_length=255)
stripeSubscriptionId = models.CharField(max_length=255)
def __str__(self):
return self.user.username

How to use a user as a ForeignKey in a Django model

I've got this model in my Django application:
class ClubSession(models.Model):
location = models.CharField(max_length=200)
coach = models.ForeignKey('auth.User', on_delete=models.CASCADE)
date = models.DateTimeField(default=now)
details = models.TextField()
def __str__(self):
return self.title
I can run python manage.py makemigrations club_sessions without issue but when I thn run python manage.py migrate club_sessions I get ValueError: Field 'id' expected a number but got 'username'. username is a superuser and already exists.
How do I resolve this?
This is the latest migration:
# Generated by Django 3.0.6 on 2020-05-28 15:07
from django.conf import settings
from django.db import migrations, models
import django.db.models.deletion
class Migration(migrations.Migration):
dependencies = [
migrations.swappable_dependency(settings.AUTH_USER_MODEL),
('club_sessions', '0004_auto_20200528_1450'),
]
operations = [
migrations.AlterField(
model_name='clubsession',
name='coach',
field=models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to=settings.AUTH_USER_MODEL),
),
migrations.AlterField(
model_name='clubsession',
name='location',
field=models.CharField(max_length=200),
),
]
By default Django lets a ForeignKey refer to the primary key of the target model. This also has some advantages to make relations more uniform.
If you really want to save the username in the ForeignKey, you can specify a to_field=… parameter [Django-doc] and let it refer to a column that is unique (the username of the default User model is unique), so we can refer to it with:
from django.conf import settings
class ClubSession(models.Model):
location = models.CharField(max_length=200)
coach = models.ForeignKey(
settings.AUTH_USER_MODEL,
on_delete=models.CASCADE,
to_field='username'
)
date = models.DateTimeField(default=now)
details = models.TextField()
def __str__(self):
return self.title
You will need to remove the already existing migration and make a new one in order to migrate the database properly.
Note: It is normally better to make use of the settings.AUTH_USER_MODEL [Django-doc] to refer to the user model, than to use the User model [Django-doc] directly. For more information you can see the referencing the User model section of the documentation.

Django migration not calling overridden save() method?

I have a model SessionCategory which is similar to the following:
from django.db import models
from django.utils.text import slugify
class SessionCategory(models.Model):
name = models.CharField(max_length=255, unique=True)
name_slug = models.CharField(max_length=255, null=True)
def save(self, *args, **kwargs):
if not self.name_slug:
self.name_slug = slugify(self.name)
super().save(*args, **kwargs)
So the name_slug field, which I'd like to add, is a slugified version of the name field.
I've run the following data migration:
from __future__ import unicode_literals
from django.db import migrations, models
def generate_name_slugs(apps, schema_editor):
SessionType = apps.get_model('lucy_web', 'SessionType')
for session_type in SessionType.objects.all():
session_type.save()
class Migration(migrations.Migration):
dependencies = [
('lucy_web', '0163_auto_20180627_1309'),
]
operations = [
migrations.AddField(
model_name='sessioncategory',
name='name_slug',
field=models.CharField(max_length=255, null=True),
),
migrations.RunPython(
generate_name_slugs,
reverse_code=migrations.RunPython.noop),
]
However, if I check the database afterward, the name_slug fields are all null:
I've also reversed the migration and re-run it setting a trace (import ipdb; ipdb.set_trace()) in the overridden save() method, but it didn't cause Python to drop into the debugger, confirming that that method is not called.
Why is the overridden save() method not getting called? Do I have to replicate the code in the generate_name_slugs function?
This should help for SessionType... SessionCategory can be modified the same way...
def generate_name_slugs(apps, schema_editor):
import lucy_web.models as m
for session_type in m.SessionType.objects.all():
session_type.save()

Renaming models(tables) in Django

so I've already created models in Django for my db, but now want to rename the model. I've change the names in the Meta class and then make migrations/migrate but that just creates brand new tables.
I've also tried schemamigration but also not working, I'm using Django 1.7
Here's my model
class ResultType(models.Model):
name = models.CharField(max_length=150)
ut = models.DateTimeField(default=datetime.now)
class Meta:
db_table = u'result_type'
def __unicode__(self):
return self.name
Cheers
Django does not know, what you are trying to do. By default it will delete old table and create new.
You need to create an empty migration, then use this operation (you need to write it by yourself):
https://docs.djangoproject.com/en/stable/ref/migration-operations/#renamemodel
Something like this:
from django.db import migrations
class Migration(migrations.Migration):
dependencies = [
('yourappname', '0001_initial'),
]
operations = [
migrations.RenameModel("OldName", "NewName")
]

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