Using Django 2.2 I added a custom clean() method to a model.
class MyModel(Model):
employees = models.ManyToManyField(Employee)
def clean(self):
raise ValidationError({'non_field_errors': _("Error message here.")})
super().clean()
I am showing this model in the Django admin using an InlineModelAdmin, TabularInline to be precise, code looks like this:
class MyModelInline(BaseModelTabularInline):
model = MyModel.employees.through
And in EmployeeAdmin:
#admin.register(Employee)
class EmployeeAdmin(BaseModelAdmin):
inlines = (MyModelInline)
I've hidden some code, don't know if my employer would like me to share it. But when I now try to save an instance of MyModel using the InlineModelAdmin, I get an error 'MyModelForm' has no field named 'non_field_errors'.
Can anyone tell me how to have this field available, so that I can display potential validation errors (coming from MyModel.clean())
PS.
I notice that raising ValidationErrors for other fields (that are on my model) works perfecly, example:
raise ValidationError({'confidential_level': _("Error message.")})
Use __all__ or better, from django.core.exceptions import NON_FIELD_ERRORS and use that (which by default is "__all__")
I wrote a custom validator, which will raise ValidationError if given field value is negative.
def validate_positive(value):
if value < 0:
raise ValidationError(
_('%(value) is negative number'),
params = {'value': value}
)
i added this to my model field via the field’s validators argument
class Book(models.Model):
user = models.ForeignKey(User,on_delete=models.CASCADE)
title = models.CharField(max_length=50)
price = models.IntegerField(default=0,validators=[validate_positive])
quantity = models.IntegerField(default=0,validators=[validate_positive])
But while creating object it's not raising any error if price is less than zero.
I don't know where i am doing wrong and i am new to django.
I am using Django 1.9.
Please help me .
Validators are used for forms, not for creating an object. If you're creating an object outside of a form then you need to provide an alternative way to validate input.
The easiest way to do this is to call the model's full_clean method before saving as shown in the docs
from django.core.exceptions import ValidationError
try:
article.full_clean()
except ValidationError as e:
# Do something based on the errors contained in e.message_dict.
# Display them to a user, or handle them programmatically.
pass
This is similar to what would happen from a form, and would call any validators on your model fields.
I ran into the same issue. So the validators only work when you are using Forms and Model Form to fill it.
You can validate the validators in the shell though.
python manage.py shell
>>>from app.models import Book
>>>Book.price.field.run_validators(value=<undesirable value>)
This would raise a validation error so you can be sure your validation is working.
I don't understand this behaviour. Let's say I open a Django shell and type:
from django.contrib.auth.models import User
user = User.objects.create(username="toto", email="titi")
Why does Django let me create this user (with an invalid email) without raising an error?
I have the same "no verification behaviour" creating a user in a POST in my API created with tastypie.
The question is:
As Django does not seem to check this by itself, where am I supposed to perform this kind of verifications sothat I don't have to write them several times (since a user can be created in several ways like website, API, etc.)?
Thanks.
Django doesn't implicitly do any validation if you just call .create() or .save() - you need to explicitly use model validation, or save the object via a
ModelForm. Your example with model validation would look like this:
user = User(username="toto", email="titi")
try:
user.full_clean()
except ValidationError as e:
# handle the error...
pass
user.save()
Or using a ModelForm:
class UserForm(forms.ModelForm):
class Meta:
model = User
f = UserForm(dict(username="toto", email="titi"))
if f.is_valid():
user = f.save()
else:
# handle error, ...
pass
Both model validation and ModelForms invoke the model field's validators, so in the case of the User's email, no additional work is needed for validation. If you need to do custom validation, you can do this in the ModelForm class - it is common to have a forms.py file in the app as a central place for Forms and ModelForms.
The same goes for Tastypie - the default configuration assumes the data submitted is valid. You can override this with the FormValidation class, which uses a Django Form or ModelForm for its validation. A full example would look something like this:
class UserResource(ModelResource):
class Meta:
queryset = User.objects.all()
validation = FormValidation(form_class=UserForm) # UserForm from above
# more options here....
I am new in Django and even after trying thoroughly to find an answer for this question, I couldn't find any. =/
I am using UserCretionForm to create my users and I wanted to know a couple of things:
1 - How can I manage this form's properties? (e.g. I don't want to show the tips like "Required. 30 charact..." or "Enter the same password as above, for verification.")
2 - I want to make it show other customized fields. How can I do it? (please, try to be clear where I have to write the codes you'll show me as I am not an expert =D ). (e.g. Here in Brazil we have some national info I need to store. That is why I need these fields.)
Thanks in advance! (Y)
Changing the default validator messages
You can change the error messages for the default validators via the error_messages argument to a form field.
To find out which validators exist per field, check here: https://docs.djangoproject.com/en/dev/ref/forms/fields/#built-in-field-classes
class MyForm(UserCreationForm):
def __init__(self, *args, **kwargs):
super(MyForm, self).__init__(*args, **kwargs)
self.fields['username'].error_messages = {'invalid': 'foobar'}
self.fields['password1'].error_messages = {'required': 'required, man'}
Adding new fields to an existing form
If you want to add new fields, you'd add them via subclassing (which is just python).
If you subclass UserCreationForm and add a field to it, you end up with a new form class that simply has the original's fields and your new ones.
class MyForm(UserCreationForm):
extra_field = forms.CharField()
Overriding the admin form
If you are trying to override the UserCreationForm that the admin site uses by default, you'll have to register a new ModelAdmin for the User moder.
from django.contrib import admin
from django.contrib.auth.admin import UserAdmin
from django.contrib.auth.models import User
from foo import MyNewUserCreationForm
class NewUserAdmin(UserAdmin):
add_form = MyNewUserCreationForm
admin.site.unregister(User)
admin.site.register(User, NewUserAdmin)
I need to patch the standard User model of contrib.auth by ensuring the email field entry is unique:
User._meta.fields[4].unique = True
Where is best place in code to do that?
I want to avoid using the number fields[4]. It's better to user fields['email'], but fields is not dictionary, only list.
Another idea may be to open a new ticket and upload a patch with new parameter inside settings.py:
AUTH_USER_EMAIL_UNIQUE = True
Any suggestions on the most correct way to achieve email address uniqueness in the Django User model?
Caution:
The code below was written for an older version of Django (before Custom
User Models were introduced). It contains a race condition, and
should only be used with a Transaction Isolation Level of SERIALIZABLE
and request-scoped transactions.
Your code won't work, as the attributes of field instances are read-only. I fear it might be a wee bit more complicated than you're thinking.
If you'll only ever create User instances with a form, you can define a custom ModelForm that enforces this behavior:
from django import forms
from django.contrib.auth.models import User
class UserForm(forms.ModelForm):
class Meta:
model = User
def clean_email(self):
email = self.cleaned_data.get('email')
username = self.cleaned_data.get('username')
if email and User.objects.filter(email=email).exclude(username=username).exists():
raise forms.ValidationError(u'Email addresses must be unique.')
return email
Then just use this form wherever you need to create a new user.
BTW, you can use Model._meta.get_field('field_name') to get fields by name, rather than by position. So for example:
# The following lines are equivalent
User._meta.fields[4]
User._meta.get_field('email')
UPDATE
The Django documentation recommends you use the clean method for all validation that spans multiple form fields, because it's called after all the <FIELD>.clean and <FIELD>_clean methods. This means that you can (mostly) rely on the field's value being present in cleaned_data from within clean.
Since the form fields are validated in the order they're declared, I think it's okay to occasionally place multi-field validation in a <FIELD>_clean method, so long as the field in question appears after all other fields it depends on. I do this so any validation errors are associated with the field itself, rather than with the form.
What about using unique_together in a "different" way? So far it works for me.
class User(AbstractUser):
...
class Meta(object):
unique_together = ('email',)
Simply use below code in models.py of any app
from django.contrib.auth.models import User
User._meta.get_field('email')._unique = True
In settings module:
# Fix: username length is too small,email must be unique
from django.contrib.auth.models import User, models
User._meta.local_fields[1].__dict__['max_length'] = 75
User._meta.local_fields[4].__dict__['_unique'] = True
It's amazing, but I found a best solution for me!
django-registration have form with checking uniqueness of email field: RegistrationFormUniqueEmail
example of usage here
Your form should look something like this.
def clean_email(self):
email = self.cleaned_data.get('email')
username = self.cleaned_data.get('username')
print User.objects.filter(email=email).count()
if email and User.objects.filter(email=email).count() > 0:
raise forms.ValidationError(u'This email address is already registered.')
return email
To ensure a User, no matter where, be saved with a unique email, add this to your models:
#receiver(pre_save, sender=User)
def User_pre_save(sender, **kwargs):
email = kwargs['instance'].email
username = kwargs['instance'].username
if not email: raise ValidationError("email required")
if sender.objects.filter(email=email).exclude(username=username).count(): raise ValidationError("email needs to be unique")
Note that this ensures non-blank email too. However, this doesn't do forms validation as would be appropriated, just raises an exception.
Django has a Full Example on its documentation on how to substitute and use a Custom User Model, so you can add fields and use email as username.
One possible way to do this is to have a pre-save hook on the User object and reject the save of the email already exists in the table.
I think that the correct answer would assure that uniqueness check was placed inside the database (and not on the django side). Because due to timing and race conditions you might end with duplicate emails in the database despite having for example pre_save that does proper checks.
If you really need this badly I guess you might try following approach:
Copy User model to your own app, and change field email to be unique.
Register this user model in the admin app (using admin class from django.contrib.auth.admin)
Create your own authentication backend that uses your model instead of django one.
This method won't make email field unique at the database level, but it's worth trying.
Use a custom validator:
from django.core.exceptions import ValidationError
from django.contrib.auth.models import User
def validate_email_unique(value):
exists = User.objects.filter(email=value)
if exists:
raise ValidationError("Email address %s already exists, must be unique" % value)
Then in forms.py:
from django.contrib.auth.models import User
from django.forms import ModelForm
from main.validators import validate_email_unique
class UserForm(ModelForm):
#....
email = forms.CharField(required=True, validators=[validate_email_unique])
#....
Add the below function in any of the models.py file. Then run makemigrations and migrate. Tested on Django1.7
def set_email_as_unique():
"""
Sets the email field as unique=True in auth.User Model
"""
email_field = dict([(field.name, field) for field in MyUser._meta.fields])["email"]
setattr(email_field, '_unique', True)
#this is called here so that attribute can be set at the application load time
set_email_as_unique()
Since version 1.2 (May 11th, 2015) there has been a way to dynamically import any chosen registration form using the settings option REGISTRATION_FORM.
So, one could use something like this:
REGISTRATION_FORM = 'registration.forms.RegistrationFormUniqueEmail'
This is documented here.
And here's the link to the changelog entry.
Django does not allow direct editing User object but you can add pre_save signal and achieve unique email. for create signals u can follow https://docs.djangoproject.com/en/2.0/ref/signals/. then add the following to your signals.py
#receiver(pre_save, sender=User)
def check_email(sender,instance,**kwargs):
try:
usr = User.objects.get(email=instance.email)
if usr.username == instance.username:
pass
else:
raise Exception('EmailExists')
except User.DoesNotExist:
pass
Add somewhere this:
User._meta.get_field_by_name('email')[0]._unique = True
and then execute SQL similar to this:
ALTER TABLE auth_user ADD UNIQUE (email);
The first answer here is working for me when I'm creating new users, but it fails when I try to edit a user, since I am excluding the username from the view. Is there a simple edit for this that will make the check independent of the username field?
I also tried including the username field as a hidden field (since I don't want people to edit it), but that failed too because django was checking for duplicate usernames in the system.
(sorry this is posted as an answer, but I lack the creds to post it as a comment. Not sure I understand Stackoverflow's logic on that.)
You can use your own custom user model for this purpose. You can use email as username or phone as username , can have more than one attribute.
In your settings.py you need to specify below settings
AUTH_USER_MODEL = 'myapp.MyUser'.
Here is the link that can help you .
https://docs.djangoproject.com/en/1.8/topics/auth/customizing/#auth-custom-user
from an User inherited model, redefine the attribute correctly. It should work, as is it's not usefull to have that in django core because it's simple to do.
I went to \Lib\site-packages\django\contrib\auth\models
and in class AbstractUser(AbstractBaseUser, PermissionsMixin):
I changed email to be:
email = models.EmailField(_('email address'), **unique=True**, blank=True)
With this if you try to register with email address already present in the database you will get message: User with this Email address already exists.