django-extra-field-validation

Table of Contents

Background

Installation

pip install django-extra-field-validation

Usage

Require all fields

from django.db import models
from extra_validator import FieldValidationMixin
class TestModel(FieldValidationMixin, models.Model):
 amount = models.DecimalField(max_digits=5, decimal_places=2, null=True, blank=True)
 fixed_price = models.DecimalField(max_digits=7, decimal_places=2, null=True, blank=True)
 percentage = models.DecimalField(max_digits=3, decimal_places=0, null=True, blank=True)
 REQUIRED_FIELDS = ['amount'] # Always requires an amount to create the instance.

In [1]: from decimal import Decimal
In [2]: from demo.models import TestModel
In [3]: TestModel.objects.create(fixed_price=Decimal('3.00'))
---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
...
ValueError: {'amount': ValidationError([u'Please provide a value for: "amount".'])}

Require at least one field in a collection

from django.db import models
from extra_validator import FieldValidationMixin
class TestModel(FieldValidationMixin, models.Model):
 amount = models.DecimalField(max_digits=5, decimal_places=2, null=True, blank=True)
 fixed_price = models.DecimalField(max_digits=7, decimal_places=2, null=True, blank=True)
 percentage = models.DecimalField(max_digits=3, decimal_places=0, null=True, blank=True)
 REQUIRED_TOGGLE_FIELDS = [
 ['amount', 'fixed_price', 'percentage'], # Require only one of the following fields.
 ]

In [1]: from decimal import Decimal
In [2]: from demo.models import TestModel
In [3]: TestModel.objects.create(amount=Decimal('2.50'), fixed_price=Decimal('3.00'))
---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
...
ValueError: {'fixed_price': ValidationError([u'Please provide only one of: Amount, Fixed price, Percentage'])}

Optionally require at least one field in a collection

from django.db import models
from extra_validator import FieldValidationMixin
class TestModel(FieldValidationMixin, models.Model):
 amount = models.DecimalField(max_digits=5, decimal_places=2, null=True, blank=True)
 fixed_price = models.DecimalField(max_digits=7, decimal_places=2, null=True, blank=True)
 percentage = models.DecimalField(max_digits=3, decimal_places=0, null=True, blank=True)
 OPTIONAL_TOGGLE_FIELDS = [
 ['fixed_price', 'percentage'] # Optionally validates that only fixed price/percentage are provided when present.
 ]

In [1]: from decimal import Decimal
In [2]: from demo.models import TestModel
In [3]: first_obj = TestModel.objects.create(amount=Decimal('2.0'))
In [4]: second_obj = TestModel.objects.create(amount=Decimal('2.0'), fixed_price=Decimal('3.00'))
In [5]: third_obj = TestModel.objects.create(amount=Decimal('2.0'), fixed_price=Decimal('3.00'), percentage=Decimal('10.0'))
---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
...
ValueError: {'percentage': ValidationError([u'Please provide only one of: Fixed price, Percentage'])}

Conditionally require all fields

from django.db import models
from django.conf import settings
from extra_validator import FieldValidationMixin
class TestModel(FieldValidationMixin, models.Model):
 user = models.ForeignKey(settings.AUTH_USER_MODEL)
 amount = models.DecimalField(max_digits=5, decimal_places=2, null=True, blank=True)
 fixed_price = models.DecimalField(max_digits=7, decimal_places=2, null=True, blank=True)
 percentage = models.DecimalField(max_digits=3, decimal_places=0, null=True, blank=True)
 CONDITIONAL_REQUIRED_FIELDS = [
 (
 lambda instance: instance.user.is_active, ['amount', 'percentage'],
 ),
 ]

In [1]: from decimal import Decimal
in [2]: from django.contrib.auth import get_user_model
In [3]: from demo.models import TestModel
In [4]: user = get_user_model().objects.create(username='test', is_active=True)
In [5]: first_obj = TestModel.objects.create(user=user, amount=Decimal('2.0'))
---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
...
ValueError: {u'percentage': ValidationError([u'Please provide a value for: "percentage"'])}

Conditionally require at least one field in a collection

from django.db import models
from django.conf import settings
from extra_validator import FieldValidationMixin
class TestModel(FieldValidationMixin, models.Model):
 user = models.ForeignKey(settings.AUTH_USER_MODEL)
 amount = models.DecimalField(max_digits=5, decimal_places=2, null=True, blank=True)
 fixed_price = models.DecimalField(max_digits=7, decimal_places=2, null=True, blank=True)
 percentage = models.DecimalField(max_digits=3, decimal_places=0, null=True, blank=True)
 CONDITIONAL_REQUIRED_TOGGLE_FIELDS = [
 (
 lambda instance: instance.user.is_active, ['fixed_price', 'percentage', 'amount'],
 ),
 ]

In [1]: from decimal import Decimal
in [2]: from django.contrib.auth import get_user_model
In [3]: from demo.models import TestModel
In [4]: user = get_user_model().objects.create(username='test', is_active=True)
In [5]: first_obj = TestModel.objects.create(user=user)
---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
...
ValueError: {'__all__': ValidationError([u'Please provide a valid value for any of the following fields: Fixed price, Percentage, Amount'])}
In [6]: second_obj = TestModel.objects.create(user=user, amount=Decimal('2'), fixed_price=Decimal('2'))
---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
...
ValueError: {'__all__': ValidationError([u'Please provide only one of the following fields: Fixed price, Percentage, Amount'])}

Model Attributes

# A list of required fields
REQUIRED_FIELDS = []
# A list of fields with at most one required.
REQUIRED_TOGGLE_FIELDS = []
# A list of field with at least one required.
REQUIRED_MIN_FIELDS = []
# Optional list of fields with at most one required.
OPTIONAL_TOGGLE_FIELDS = []
# Conditional field required list of tuples the condition a boolean or a callable.
# [(lambda user: user.is_admin, ['first_name', 'last_name'])] : Both 'first_name' or 'last_name'
# If condition is True ensure that all fields are set
CONDITIONAL_REQUIRED_FIELDS = []
# [(lambda user: user.is_admin, ['first_name', 'last_name'])] : Either 'first_name' or 'last_name'
# If condition is True ensure that at most one field is set
CONDITIONAL_REQUIRED_TOGGLE_FIELDS = []
# [(lambda user: user.is_admin, ['first_name', 'last_name'])] : At least 'first_name' or 'last_name' provided or both
# If condition is True ensure that at least one field is set
CONDITIONAL_REQUIRED_MIN_FIELDS = []
# [(lambda user: user.is_admin, ['first_name', 'last_name'])] : Both 'first_name' and 'last_name' isn't provided
# If condition is True ensure none of the fields are provided
CONDITIONAL_REQUIRED_EMPTY_FIELDS = []

License

TODO's