Source code for halogen.validators

"""Halogen basic type validators."""

from halogen import exceptions


[docs]class Validator(object): """Base validator."""
[docs] @classmethod def validate(cls, value): """Validate the value. :param value: Value to validate. :raises: :class:`halogen.exception.ValidationError` exception when value is invalid. """
[docs]class LessThanEqual(Validator): """Less than or equal.""" value_err = u"{0} is bigger than {1}" def __init__(self, value, value_err=None): """Less than or equal validator constructor. :param value: Comparison value (constant or collable). :param value_err: ValidationError message if length is greater than value. """ self.value = value if value_err is not None: self.value_err = value_err
[docs] def validate(self, value): compare_value = self.value() if callable(self.value) else self.value if value > compare_value: raise exceptions.ValidationError(self.value_err.format(value, compare_value)) return True
[docs]class GreatThanEqual(Validator): """Greater than or equal.""" value_err = u"{0} is smaller than {1}" def __init__(self, value, value_err=None): """Greater than or equal validator constructor. :param value: Comparison value (constant or collable). :param value_err: ValidationError message if length is less than value. """ self.value = value if value_err is not None: self.value_err = value_err
[docs] def validate(self, value): compare_value = self.value() if callable(self.value) else self.value if value < compare_value: raise exceptions.ValidationError(self.value_err.format(value, compare_value)) return True
[docs]class Length(Validator): """Length validator that checks the length of a List-like type.""" min_err = "Length is less than {0}" max_err = "Length is greater than {0}" def __init__(self, min_length=None, max_length=None, min_err=None, max_err=None): """Length validator constructor. :param min_length: Minimum length (constant or collable), optional. :param max_length: Maximum length (constant or collable), optional. :param min_err: ValidationError message if length is less than minimal value. :param max_err: ValidationError message if length is greater than maximal value. """ self.min_length = min_length self.max_length = max_length if min_err is not None: self.min_err = min_err if max_err is not None: self.max_err = max_err
[docs] def validate(self, value): """Validate the length of a list. :param value: List of values. :raises: :class:`halogen.exception.ValidationError` exception when length of the list is less than minimum or greater than maximum. """ try: length = len(value) except TypeError: length = 0 if self.min_length is not None: min_length = self.min_length() if callable(self.min_length) else self.min_length if length < min_length: raise exceptions.ValidationError(self.min_err.format(min_length)) if self.max_length is not None: max_length = self.max_length() if callable(self.max_length) else self.max_length if length > max_length: raise exceptions.ValidationError(self.max_err.format(max_length))
[docs]class Range(object): """Range validator. Validator which succeeds if the value it is passed is greater or equal to ``min`` and less than or equal to ``max``. If ``min`` is not specified, or is specified as ``None``, no lower bound exists. If ``max`` is not specified, or is specified as ``None``, no upper bound exists. """ min_err = u"{val} is less than minimum value {min}" max_err = u"{val} is greater than maximum value {max}" def __init__(self, min=None, max=None, min_err=None, max_err=None): """Range validator constructor. :param min: Minimal value of range (constant or collable), optional. :param max: Maximal value of range (constant or collable), optional. :param min_err: ValidationError message if value is less than minimal value of range. :param max_err: ValidationError message if value is greater than maximal value of range. """ self.min = min self.max = max if min_err is not None: self.min_err = min_err if max_err is not None: self.max_err = max_err
[docs] def validate(self, value): """Validate value. :param value: Value which should be validated. :raises: :class:`halogen.exception.ValidationError` exception when either if value less than min in case when min is not None or if value greater than max in case when max is not None. """ if self.min is not None: min_value = self.min() if callable(self.min) else self.min if value < min_value: raise exceptions.ValidationError(self.min_err.format(val=value, min=min_value)) if self.max is not None: max_value = self.max() if callable(self.max) else self.max if value > max_value: raise exceptions.ValidationError(self.max_err.format(val=value, max=max_value))