Django - Models extension Vs User Profile
I want add some custom fields like following
1. ssn
2. is_manager
3. manager
I have 2 choices -
Extend AbstractBaseUser
OR
Create User profile based on signal and have OnetoOne field.
Which one is better, future proof, DB migration friendly and maintainable ?
The Django documentation answers this question in detail:
If you wish to store information related to User, you can use a OneToOneField to a model containing the fields for additional information. This one-to-one model is often called a profile model, as it might store non-auth related information about a site user.
In your case, the added fields do not seem to be authentication related, so your best bet is to use the user profile method. Substituting a custom user model is overkill for such purposes.
Related
A great greetings community
My question is related with the kind of manage users and the schema users in Django, In beginning I ask to you apologize just in case that my questions can will be too "newbies" or without sense, I am starting to related me with the Django Users schemas and their different possibilities of work in the projects.
I have the following situation.
I am building an application in which I will have three differents user types:
Medical
Patient
Physiotherapist
I am using the default Django authentication scheme (django.contrib.auth).
Initially, I did think in this scheme of entities in which the User table is the auth_user table in where Django save the users created:
I have the is_patient, is_medical and is_physiotherapist fields like boolean attributes in the User table.
Like a particular detail I understand that in the Django default model User is not possible modify or add attributes or fields.
This is an important and powerful reason to I cannot add the is_patient, is_medical and is_physiotherapist boolean fields in User table.
A classic recommendation is extend the User model with a Userprofile table in which I add fields or attributes to User Model through of OneToOne relationship. A basic sample is such as follow:
Is of this way that I get that my users in Django can have the field photo and upload one in a given moment ...
Taking advantage of the previous,
The following schema can be suited or can be an alternative for manage user roles (patient, medical and physiotherapist user types) ?
I will have relationships between:
User medical and user patients
user physiotherapist and user patients
and so between them and other tables ...
With this approach these relationships don't will be affected?
The different users will be saved between the Users and UserProfile table.
Is this a good practice in the scalability sense? My tables could be crash or my database?
In addition, I also have seen other alternatives such as:
Role Table/Model
I will have a role table/model independent or separate and that this can be related with the Django User model (One User can will have many roles by example)
This approach can be useful when I want store exclusive information about of a role in specia?
Django Permissions and Authorization
I ignore or unknown the granularity grade that let will me work. Of a single way I have been see that the permissions and authorizations system let will me work with create and edit and remove operations ....
Here, can I see the groups creation?
For example a medical group and allocate them permissions and linked this permissions to the users that compose the group ? Is this another good alternative?
This option seem more single although I don't know if an user could make some operations according to the group privileges that have ... I don't know if this thinking is correct/right
AUTH_USER_MODEL Creating a Custom User model
My requirements for patient, medical and physiotherapist users, require build a custom user model?
In this situation, especially if you want to store different infos for Patients, Medics and Physiotherapists you can create a Model for each and have a OneToOne field for each to the User model.
class Medic(models.Model):
user = models.OneToOneField(User, primary_key=True)
# other fields
class Physio(models.Model):
user = models.OneToOneField(User, primary_key=True)
# other fields
class Patient(models.Model):
user = models.OneToOneField(User, primary_key=True)
# other fields
This way you can give different permissions/roles implicitly in your application logic for each type of user (and still use the groups and permissions that Django offers if you need them for special cases, eg ChiefMedical...).
You will have to define some methods for your application logic like
def user_is_patient(user):
...
If you follow this path it is a good idea to have good tests to make sure that you don't get unexpected things like a user who is a Medic and a Physio...
Django lets you subclass the user model as well. Under the covers it would do the same thing as the code above, so it is probably better to do it explicitly as shown above (this way it is less probable that you access attributes that don't exist in that object!)
Taking advantage of the previous, The following schema can be suited or can be an alternative for manage user roles (patient, medical and physiotherapist user types) ?
The schema you show isn't great because it makes you store the information for all user types in the same table (and with the same fields). For example, Medics and Physios will have a blood type field type like Patients which will probably not be defined.
The different users will be saved between the Users and UserProfile table. Is this a good practice in the scalability sense? My tables could be crash or my database?
There should be no scalability problems with this solution (as long as you don't have millions new entries writes every day) and you can always optimise the database at a further point. However, you will have to make sure that your app doesn't accept 'forbidden' entries (e.g. users with no Medic, Physio or Patient profile)
Here, can I see the groups creation? For example a medical group and allocate them permissions and linked this permissions to the users that compose the group ? Is this another good alternative? This option seem more single although I don't know if an user could make some operations according to the group privileges that have ... I don't know if this thinking is correct/right
You can (should) use Django's permission system to give permissions to your users. You can use them to give different rights to users of the same type (for example Medics that have more permissions than others... or have groups for chief physios...)
Django lets you assign permissions to a group.
But I don't think groups can replace the custom models for each user, since you want to store information for them. Having custom models and groups would be redundant and make your app harder to maintain.
My requirements for patient, medical and physiotherapist users, require build a custom user model?
This option wouldn't be great (unless it is your only option) because your app won't be reusable and you might have problems with some packages as well.
You can create a custom User model or not, in any case, you could have three separate models for storing pertinent data, depending on whether the user is patient, medical, physiotherapist, or any combination of these.
If your permissions scheme is determined solely by the role (patient, medical, physiotherapist) then you don't need to use Django's permissions system, because you know the role(s) of any user and you can, in the worst scenario, hardcode authorization rules.
I gave a glance at question's comments and I view some issues:
()
I realized that your user model does not match with the original data model since having get_medical_profile, get_patient_profile and get_physiotherapist_profile functions inside user model, with that you are assuming that any user could have multiple profiles at the same time, which isn't reflected neither in your profile models (Medical, Patient and Physiotherapist) using OneToOneField nor in original data model of the question, it's an important thing about abstraction and class-responsibility. The requirement (according the model below) seems to say "one user can have only one profile".
So.. I think this can be solved in a straightforward and clean way, you don't need to involve in overall authentication esquema like groups and permissions or adding additional attributes to user model:
class UserProfile(models.Model):
user = models.OneToOneField(User)
# common fields shared by medical, patient and physiotherapist profiles
class MedicalUser(models.Model):
profile = models.OneToOneField(UserProfile)
# medical fields here
class PatientUser(models.Model):
profile = models.OneToOneField(UserProfile)
# patient fields here
class PhysiotherapistUser(models.Model):
profile = models.ForeignKey(UserProfile)
# patient fields here
As you see, you can have a profile which contains common fields shared by all profiles. and each profile has an specific model.
In addition, you can check if user is medical by this small function below, then if there is no an medical profile associated with profile then it will raise exception and it means it's a profile unspecified:
def is_medical_profile(profile):
try:
profile.medical_user
return True
except:
return False
You can also use it in your templates (as a custom template tag) in this way:
{% if profile | is_medical_profile %}
With this approach you don't need to setup AUTH_USER_MODEL
I hope this improves your solution.
Additional notes:
Just in case you decide to have a custom user model, setup settings.AUTH_USER_MODEL and use it for foreign keys to User.
On a piece of text of awesome book Two scoops of Django says:
From Django 1.5 onwards, the official preferred way to attach
ForeignKey, OneToOneField, or ManyToManyField to User
Therefore, your user profile model would change as follows:
from django.conf import settings
from django.db import models
class UserProfile(models.Model):
user = models.OneToOneField(settings.AUTH_USER_MODEL)
Yes, it looks a bit strange, but that's what the official Django docs advice.
#geoom #Ire #lorenzo-peña I 've created an user through Django admin site and I checked their attributes (is_medical, is_patient, is_physiotherapist) via python shell
In [6]: User.objects.filter(username='agarcial').values('is_medical','is_patient','is_physiotherapist')
Out[6]: [{'is_physiotherapist': True, 'is_patient': True, 'is_medical': True}]
For the moment in my views.py I am doing that an user sign in only when this be one of three user types (medical, patient or physiotherapist)
# Create your views here.
class ProfileView(LoginRequiredMixin, TemplateView):
template_name = 'profile.html'
def get_context_data(self, **kwargs):
self.request.session['Hi'] = True
context = super(ProfileView, self).get_context_data(**kwargs)
is_auth = False
name = None
# Check if in the request goes the user
user = self.request.user
# Check about of possible cases (For now is one profile)
if user.is_medical:
#if self.request.user.is_authenticated():
print (user.is_medical)
is_auth = True
profile=user.get_medical_profile()
#name = self.request.user.username
data = {
'is_auth':is_auth,
'profile':profile,
}
context.update({'userprofile':profile, 'data':data})
elif user.is_patient:
print (user.is_patient)
is_auth=True
profile=user.get_patient_profile()
data = {
'is_auth':is_auth,
'profile':profile,
}
context.update({'userprofile':profile,'data':data})
elif user.is_physiotherapist:
print (user.is_physiotherapist)
is_auth=True
profile=user.get_physiotherapist_profile()
data = {
'is_auth':is_auth,
'profile':profile,
}
context.update({'userprofile':profile,'data':data})
return context
def get_userprofile(self):
return self.request.user.userprofile
If I check the other possible combinations (User patient,medical and physiotherapist) this could work?
I think create groups for (Medicals, Patients, Physiotherapists) and binding users for the authorization topic, although I should review other things for authorization process such as django guardian for example?
How about this?
Probably some of you would tell that is a recurrent topic, but after reading many articles, it still seems very ambiguous to me. My question is about the best way to use and to extend the User model preserving the authentication (and others) mechanisms available in Django. However, I prefer to describe my design:
There are users (Patients) that can sign up providing basic info (first name, last name, birth date, gender, email, password). Preferably, email should replace the username.
When a Patient is in the application, it can register a new Patient (imagine a member of the family), but email and password are not required because they won't log into the system.
For the first part, Django doc propose to extend User with a OneToOne relation to a Profile. However, to replace username by email they propose then to create a custom User extending from an AbstractUser, as well as an associated UserManager. The second requirement is like doing a one-to-many relation from users to users. So, according to Django, which should be the best strategy: creating a completely new user model and the one-to-many user-user adding an specific attribute that distinguish between main users and family members? OR extending Django User with a Profile and then a one-to-many relation profile-profile? Which option preserves the best the benefits of Django user authentication and model administration?
Thank you for any comment, suggestion, example.
First, if you want to use email as username, use the Django custom user functionnality. It works well.
Then, note that it's not because you created your own User that you can't extend it with a Profile.
So, a good solution could be :
Create a Django custom User without trying to add specific fields to it (the one and only purpose here is to use email to log instead of username).
Create a PatientProfile class that have a one-to-one relatioship (blank=True) with User class.
This way, a patient that can log in will be related to a User instance and will use this instance for this purpose. On the other hand, the patient who can't log in won't be related to any User instance.
In the end, there's no problem to use OneToMany relationship with PatientProfile for what's you want to do.
In Django you have some naturally defined User class. My app also has a User class defined (they dont conflict, that's not the question)
My question is, since these two User classes conceptually represent the same thing (well, users) then it would be natural to integrate them. That is, have a single User class that contains all methods and variables of both classes.
What is the best way to achieve this?
There are (at least) two possibilities:
1) Use the 'custom user' functionality of Django (since Django 1.5), or
2) Use a OneToOneField to the django.contrib.auth User from your own user class.
The first allows you to customize more, but you might get some problems if you try to use third-party-apps that are either not ready for custom users or need specific properties of the stock User. For example, Django Guardian doesn't work if you remove the User-Group relationship.
The second is less intrusive, but doesn't allow you to customize the existing fields of User. Also, you need to manually create the instance of your own user class at registration time.
You should read the documentation about Extending the existing User model.
If you wish to store information related to User, you can use a one-to-one relationship to a model containing the fields for additional information. This one-to-one model is often called a profile model, as it might store non-auth related information about a site user. For example you might create an Employee (note: called MyUser below) model:
from django.contrib.auth.models import User
class MyUser(models.Model):
user = models.OneToOneField(User)
newfield1 = models.CharField(...)
AUTH_USER_MODEL = 'myapp.MyUser'
Django 1.5+ allows us to add custom fields to a User. I want to use this fact, but I don't necessarily know what is good practice. Here is a situation I am confused on how to handle the models.
Given the option to add fields to User, if a project only has one type of User, lets say a Student model, can I simply add student-specific fields to User? I am new to Django, but I believe the alternative would be to set up general User settings, and create a Student model, and a one-to-one unique field in it call user.
Should you ever expand a Django User's fields to mimic that of a model, even if the project is guaranteed only to have one type of user?
If you only have one type of user and are using Django 1.5+, I would recommend taking advantage of the new AbstractUser. Extending Django's default user
As an example where you want to add date of birth and favorite color:
#myusers/models.py
from django.contrib.auth.models import AbstractUser
from django.db import models
class MyUser(AbstractUser):
dob = models.DateField()
favorite_color = models.CharField(max_length=32, default='Blue')
If you need more flexibility you can extend the AbstractBaseUser instead of AbstractUser, but for most basic cases you should only need AbstractUser.
Also note that in either case, you'll need to reference your user model by using settings.AUTH_USER_MODEL.
Using out example above and assuming the app it was defined in is called myusers:
#settings.py
AUTH_USER_MODEL = 'myusers.MyUser'
The method you mention of creating a Student model with a one-to-one field to the User model still works, but is not as clean (there are still cases where it makes sense if you have multiple kinds of users).
I don't normally like to reference books in answers, but I found that Two Scoops of Django's, Chapter 16 on the User model gave a much clearer explanation of where the different options are appropriate than the current version of the online Django docs. The book is overall a very useful intro to Django and was written based on 1.5. You'd have to buy the book or find someone who has it, though... (FYI: I don't get any money recommending this).
You could also take a look at this SO question/answer: https://stackoverflow.com/a/14104748/307293
You shouldn't touch the django contributed User model (from the authentication framework). This will break upgrades and you do not know what other consequences it might have.
There are two basic ways to do this:
If you just need to store additional information about a user, but don't need to change how the authentication/authorization mechanism works, create a model and add a OneToOneField to the User model. In this model, store any other miscellaneous information.
If you want to change how authentication works you can create your own User model and have django use that (1.5+ only).
I have a field Foo with a ForeignKey that points to User. I need to create filter in the admin that only displays User that have at least one Foo. This would be easy with the development version of Django, but I am stuck with the 1.3.
I have seen here how to add a custom filter using the undocumented FilterSpec class. My problem is that it requires to modify the User model. I could inherit from User, but I already ave a setup where additional data is put into a Profile model wiith a one-to.one link to User.
Is there a less intrusive way to add a custom filter to the User model?
You can actually use the foreign key relation backwards in an ORM query.
User.objects.filter(foo__isnull=False)