Base validator class

validator.py

import abc

from django.core.exceptions import ValidationError


class BaseValidator(abc.ABC):
    """
    Base validator class for collect and run validations.

    Every method starting with 'validate_' will be considered validation.
    The validation method must fail with an error. Examlpe:

    >>> class MyValidator(BaseValidator):
    ...     def validate_something(self):
    ...         raise ValidationError()
    ...
    >>> errors = MyValidator().validate(raise_exceptions=True)
    """

    def __init__(self, *args, **kwargs):
        self.errors = []

    def _get_validators(self):
        return [
            getattr(self, attr)
            for attr in dir(self) if attr.startswith('validate_')
        ]

    def validate(self, raise_exceptions=False):
        for validation in self._get_validators():
            try:
                validation()
            except ValidationError as error:
                self.errors.append(error)

        if self.errors and raise_exceptions:
            raise ValidationError(self.errors)

        return self.errors

    def is_valid(self):
        return not self.errors

    @property
    def errors_dict(self):
        return [
            {key: messages}
            for error in self.errors
            for key, messages in error.message_dict.items()
        ]