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mirror of https://github.com/netbox-community/netbox.git synced 2024-05-10 07:54:54 +00:00

108 lines
3.9 KiB
Python

from django.core.exceptions import ValidationError
from django.core import validators
# NOTE: As this module may be imported by configuration.py, we cannot import
# anything from NetBox itself.
class IsEmptyValidator:
"""
Employed by CustomValidator to enforce required fields.
"""
message = "This field must be empty."
code = 'is_empty'
def __init__(self, enforce=True):
self._enforce = enforce
def __call__(self, value):
if self._enforce and value not in validators.EMPTY_VALUES:
raise ValidationError(self.message, code=self.code)
class IsNotEmptyValidator:
"""
Employed by CustomValidator to enforce prohibited fields.
"""
message = "This field must not be empty."
code = 'not_empty'
def __init__(self, enforce=True):
self._enforce = enforce
def __call__(self, value):
if self._enforce and value in validators.EMPTY_VALUES:
raise ValidationError(self.message, code=self.code)
class CustomValidator:
"""
This class enables the application of user-defined validation rules to NetBox models. It can be instantiated by
passing a dictionary of validation rules in the form {attribute: rules}, where 'rules' is a dictionary mapping
descriptors (e.g. min_length or regex) to values.
A CustomValidator instance is applied by calling it with the instance being validated:
validator = CustomValidator({'name': {'min_length: 10}})
site = Site(name='abcdef')
validator(site) # Raises ValidationError
:param validation_rules: A dictionary mapping object attributes to validation rules
"""
VALIDATORS = {
'min': validators.MinValueValidator,
'max': validators.MaxValueValidator,
'min_length': validators.MinLengthValidator,
'max_length': validators.MaxLengthValidator,
'regex': validators.RegexValidator,
'required': IsNotEmptyValidator,
'prohibited': IsEmptyValidator,
}
def __init__(self, validation_rules=None):
self.validation_rules = validation_rules or {}
assert type(self.validation_rules) is dict, "Validation rules must be passed as a dictionary"
def __call__(self, instance):
# Validate instance attributes per validation rules
for attr_name, rules in self.validation_rules.items():
assert hasattr(instance, attr_name), f"Invalid attribute '{attr_name}' for {instance.__class__.__name__}"
attr = getattr(instance, attr_name)
for descriptor, value in rules.items():
validator = self.get_validator(descriptor, value)
try:
validator(attr)
except ValidationError as exc:
# Re-package the raised ValidationError to associate it with the specific attr
raise ValidationError({attr_name: exc})
# Execute custom validation logic (if any)
self.validate(instance)
def get_validator(self, descriptor, value):
"""
Instantiate and return the appropriate validator based on the descriptor given. For
example, 'min' returns MinValueValidator(value).
"""
if descriptor not in self.VALIDATORS:
raise NotImplementedError(
f"Unknown validation type for {self.__class__.__name__}: '{descriptor}'"
)
validator_cls = self.VALIDATORS.get(descriptor)
return validator_cls(value)
def validate(self, instance):
"""
Custom validation method, to be overridden by the user. Validation failures should
raise a ValidationError exception.
"""
return
def fail(self, message, field=None):
"""
Raise a ValidationError exception. Associate the provided message with a form/serializer field if specified.
"""
if field is not None:
raise ValidationError({field: message})
raise ValidationError(message)