import re
from mongoengine import StringField


class RegexField(StringField):
    def __init__(self, regex, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.regex = re.compile(regex)

    def validate(self, value, clean=True):
        if not self.regex.fullmatch(value):
            self.error('The given string does not match the regex for this field')