Custom Types

To build a custom type object you can inherit from Type and implement functions load(data, **kwargs) and dump(value, **kwargs):

from lollipop.types import MISSING, String
try:
    from urlparse import urlparse, urljoin
except ImportError:
    from urllib.parse import urlparse, urljoin

class URL(String):
    def load(self, data, *args, **kwargs):
        loaded = super(URL, self).load(data, *args, **kwargs)
        return urlparse(loaded)

    def dump(self, value, *args, **kwargs):
        dumped = urljoin(value)
        return super(URL, self).dump(dumped, *args, **kwargs)

Other variant is to take existing type and extend it with some validations while allowing users to add more validations:

from lollipop import types, validators

EMAIL_REGEXP = r"(^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$)"

class Email(types.String):
    def __init__(self, *args, **kwargs):
        super(Email, self).__init__(*args, **kwargs)
        self.validators.insert(0, validators.Regexp(EMAIL_REGEXP))

To simplify creating new types by adding validators to existing types there is a helper function - validated_type():

Email = validated_type(
    String, 'Email',
    validate=Regexp('(^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$)',
                    error='Invalid email')
)

Ipv4Address = validated_type(
    String, 'Ipv4Address',
    # regexp simplified for demo purposes
    validate=Regexp('^\d+\.\d+\.\d+\.\d+$', error='Invalid IP address')
)

Percentage = validated_type(Integer, validate=Range(0, 100))