# -*- coding: utf-8 -*-
import re
from watson.validators import abc
[docs]class Length(abc.Validator):
"""Validates the length of a string.
Example:
.. code-block:: python
validator = Length(1, 10)
validator('Test') # True
validator('Testing maximum') # raises ValueError
"""
[docs] def __init__(self, min=-1, max=-1,
message='"{value}" does not meet the required length'):
"""Initializes the validator.
Min, max, length are interpolated into the message.
Args:
min (int): The minimum length of the string.
max (int): The maximum length of the string.
message (string): The message to be used if the validator fails.
"""
self.message = message
if max > -1 and min > max:
raise ValueError('Min cannot be greater than max')
self.min = int(min)
self.max = int(max)
def __call__(self, value, **kwargs):
valid = True
message = None
if not value:
raise ValueError(self.message.format(
min=self.min,
max=self.max,
value=value,
length=0))
str_len = len(value)
if (self.min > -1 and str_len < self.min) or (self.max > -1 and str_len > self.max):
valid = False
message = self.message.format(
min=self.min,
max=self.max,
value=value,
length=str_len)
if not valid:
raise ValueError(message)
return valid
[docs]class Required(abc.Validator):
"""Validates whether or not a value exists.
Example:
.. code-block:: python
validator = Required()
validator('Test') # True
validator('') # raises ValueError
"""
[docs] def __init__(self, message='Value is required'):
self.message = message
def __call__(self, value, **kwargs):
if not value:
raise ValueError(self.message.format(value=value))
return True
[docs]class RegEx(abc.Validator):
"""Validates a value based on a regular expression.
Example:
.. code-block:: python
validator = RegEx('Match')
validator('Match') # True
validator('Other') # raises ValueError
"""
[docs] def __init__(self, regex, flags=0,
message='"{value}" does not match pattern "{pattern}"'):
if isinstance(regex, str):
regex = re.compile(regex, flags)
self.regex = regex
self.message = message
def __call__(self, value, **kwargs):
if not self.regex.match(value):
raise ValueError(
self.message.format(
value=value,
pattern=self.regex.pattern))
[docs]class Csrf(abc.Validator):
"""Validates a csrf token.
Example:
.. code-block:: python
validator = Csrf()
validator('submitted token')
"""
[docs] def __init__(self, token=None,
message='Cross-Site request forgery attempt detected, invalid token specified "{token}"'):
self.token = token
self.message = message
def __call__(self, value, **kwargs):
if value != self.token:
raise ValueError(self.message.format(token=value))