user inheritance in django - python

I saw a couple of ways extending user information of users and decided to adopt the model inheritance method.
for instance, I have :
class Parent(User):
contact_means = models.IntegerField()
is_staff = False
objects = userManager()
Now it is done, I've downloaded django_registration to help me out with sending emails to new users. The thing is, instead of using registration forms to register new user, I want to to invoke the email sending/acitvation capability of django_registration. So my workflow is:
1. add new Parent object in admin page.
2. send email
My problem is, the django-registration creates a new registration profile together with a new user in the user table. how do I tweak this such that I am able to add the user entry into the custom user table.
I have tried to create a
modelAdmin
and alter the save_model method to launch the create_inactive_user from django_registration, however I do not how to save the user object generated from django_registration into my Parent table when I have using model inheritance and I do not have a Foreign key attribute in my parent model.

It's probably something like:
p = Parent()
p.user_ptr = user
p.contact_means = ...
p.save()
(Django creates the foreign key for you when doing model inheritance, plus the attribute ending in _ptr)

Related

Django - Team/User relationships

I'm at a loss... I'm just learning Django and I am really rather confused about how to make a field work the way I would like it to.
I understand that Django has a native "Groups" model. However, I am looking to build my own teams model for customization and practice.
Here is my models.py file for my Users app:
from django.db import models
from django.contrib.auth.models import User
class Team(models.Model):
members = models.ManyToManyField(User)
class Profile(models.Model):
user = models.OneToOneField(User, on_delete=models.CASCADE)
admin = models.BooleanField("Admin Status")
Here's where I'm confused. I would like to be able to call the team that the user is part of directly from User.Profile. So, I want to add a field to my Profile class that will automatically populate with the team name when a user is added to a team.
A potential problem I can see is that, currently, I can assign a user to multiple teams. This doesn't bother me, perhaps I can have a Profile model field that automatically populates with a list of all the teams that the user is associated with. Regardless, I can't figure out what type of field I would need to use, or how to do this.
Does that make sense?
A potential problem I can see is that, currently, I can assign a user to multiple teams.
Indeed, you can however easily retrieve the Teams the myprofile object is a member of with:
Team.objects.filter(members__profile=myprofile)
You thus can make a property for the Profile model:
class Profile(models.Model):
user = models.OneToOneField(User, on_delete=models.CASCADE)
admin = models.BooleanField("Admin Status")
#property
def teams(self):
return Team.objects.filter(
members__profile=self
)
Then you thus access the Teams of a myprofile with myprofile.teams.
So, I want to add a field to my Profile class that will automatically populate with the team name when a user is added to a team.
From my limited knowledge of database, you can add a name field to your Team model.
Keeping in mind your requirement as mentioned in question, i would suggest you to use django reverse relations to get all the teams the profile is associated with
user_teams = User.objects.get(id='user_id').profile_set.all()[0].team_set.all()
to know more about django ORM reverse relation, here is a very short article

Django user daily updating model

I'm new in django. I want to create applications where users will be able to create objects and update them daily (add new days and new descriptions and photos).
So my question is:
1.
In models.py I need to create class Object(models.Model) and use ForeignKey(settings.AUTH_USER_MODEL) or OneToOneRel(settings.AUTH_USER_MODEL) to connect user which create object with this object ?
2.
I need to create an extra class day where there will be fields such as a subtitle description etc and add it to the object class?
3.
How I can create form or views to daily updating ?
1i. You need User and Objects model. You can use built in django User model
You have one to many relation one user can have many objects. Therefore you need foreign key. So make Object model like this:
class Object(models.Model)
title = models.CharField(max_length=100)
description = models.CharField(max_length=1000)
user = ForeignKey(model=User)
Don't understand
Django provides you simple admin which is suitable if you want to just add, update, delete. Otherwise you can use model forms to build your custom views and templates for edit database records. Model Forms
and Forms. Here you will find everything you need to create custom views with model forms.

How I can make an attribute of the child model required, if it is inheriting the User class without saving?

like http://scottbarnham.com/blog/2008/08/21/extending-the-django-user-model-with-inheritance/
but can anyone suggest how I can make an attribute of the child model required, if it is inheriting the User class without saving the user if the instance of the child model is not saved? eg.
class Customer(User):
organization = models.CharField(max_length=80, unique = True)
address = models.CharField(max_length=80)
.
..
objects = UserManager()
If in the admin.py, model Customer is registered, on execution, we get the user creation form, with password after saving it, we exit from the module. We are able to see that the user exists in the django Auth, even if the Customer is not yet created. How do I override the save of the User class. Also I need to create other users for the application the normal way. Please suggest
You're sure you're not adding an User, not a Customer. Here you are not transforming users into customers, just creating a new class. (I misread your post and thought you missed that ; I'll leave that here but anyways).
You probably don't want all users to be customers (For instance, you have staff).
Did you try removing the manager ?
Let me point out however that the Django developers themselves recommend using profiles not inheritance (See comments from James Benett in the blog article you linked).

django authentication backend

I followed the method of extending the User class for implementing custom users in my application.
As mentioned in the link, custom authentication backend needs to be written in order to return the appropriate custom user class rather than User.
However I have more than one custom users class, namely Student, Teacher,Parent.
Is there any better way than checking Student->Teacher->Parent tables to return the correct custom user?
The only solution I could think of is to actually change the User model that django uses and add a content_type field that would tell you what type of user the actual user object is. Then you could directly query on that one. You'd still need 2 queries every time to fetch the correct user object.
Alternatively you could have a model that inherits from User that encompasses all of the functionality required by your three classes, call it SuperUser for example, with a special field identifying if it is a Student, Teacher or a Parent.
Then fetch the SuperUser object for a user, thus containing all of the required data. By using the special field identifying which user type they are, you could have a proxy model that you have for each type of user (ProxyStudent, ProxyTeacher, etc) that would make it behave as it should.
This would mean you only ever have 2 database hits regardless, but you get to store the data as specified as long as you use the proxy model to access them.
class SuperUser(User):
type = models.IntegerField(choices=[(0, 'Student'), (1, 'Teacher'), (2, 'Parent')]
# insert all the data for all 3 seperate classes here
class ProxyStudent(SuperUser):
class Meta:
proxy = True
def special_student_method(self):
pass
fetch request.user
and make request.user an instance of SuperUser
student = ProxyStudent()
student.__dict__ = request.user.__dict__

Giving anonymous users the same functionality as registered ones

I'm working on an online store in Django (just a basic shopping cart right now), and I'm planning to add functionality for users to mark items as favorite (just like in stackoverflow). Models for the cart look something like this:
class Cart(models.Model):
user = models.OneToOneField(User)
class CartItem(models.Model):
cart = models.ForeignKey(Cart)
product = models.ForeignKey(Product, verbose_name="produs")
The favorites model would be just a table with two rows: user and product.
The problem is that this would only work for registered users, as I need a user object. How can I also let unregistered users use these features, saving the data in cookies/sessions, and when and if they decides to register, moving the data to their user?
I guess one option would be some kind of generic relations, but I think that's a little to complicated. Maybe having an extra row after user that's a session object (I haven't really used sessions in django until now), and if the User is set to None, use that?
So basically, what I want to ask, is if you've had this problem before, how did you solve it, what would be the best approach?
I haven't done this before but from reading your description I would simply create a user object when someone needs to do something that requires it. You then send the user a cookie which links to this user object, so if someone comes back (without clearing their cookies) they get the same skeleton user object.
This means that you can use your current code with minimal changes and when they want to migrate to a full registered user you can just populate the skeleton user object with their details.
If you wanted to keep your DB tidy-ish you could add a task that deletes all skeleton Users that haven't been used in say the last 30 days.
Seems to me that the easiest way to do this would be to store both the user id or the session id:
class Cart(models.Model):
user = models.ForeignKey(User, null=True)
session = models.CharField(max_length=32, null=True)
Then, when a user registers, you can take their request.session.session_key and update all rows with their new user id.
Better yet, you could define a "UserProxy" model:
class Cart(models.Model):
user = models.ForeignKey(UserProxy)
class UserProxy(models.Model):
user = models.ForeignKey(User, unique=True, null=True)
session = models.CharField(max_length=32, null=True)
So then you just have to update the UserProxy table when they register, and nothing about the cart has to change.
Just save the user data the user table and don't populate then userid/password tables.
if a user registers then you just have to populate those fields.
You will have to have some "cleanup" script run periodically to clear out any users who haven't visited in some arbitrary period. I'd make this cleanup optional. and have a script that can be run serverside (or via a web admin interface) to clear out in case your client wants to do it manually.
remember to deleted all related entries as well as the user entry.
I think you were on the right track thinking about using sessions. I would store a list of Product id's in the users session and then when the user registers, create a cart as you have defined and then add the items. Check out the session docs.
You could allow people that are either not logged in or don't have an account to add items to a 'temp' cart. When the person logs in to either account or creates a new account, add those items to their 'real' cart. Then by just adding a few lines to your 'add item to cart' and login functions, you can use your existing models.

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