yorm.bases.Converter

Complexity

Total Complexity

3

Size/Duplication

Total Lines	17
Duplicated Lines	0 %

Test Coverage

Coverage

100%

3 Methods

Rating	Name	Duplication	Size	Complexity
A	Converter.to_data()	0	4	1
A	Converter.to_value()	0	4	1
A	Converter.create_default()	0	4	1

"""Converter classes."""

from abc import ABCMeta, abstractclassmethod, abstractmethod

from .. import common
from . import Mappable


log = common.logger(__name__)


class Converter(metaclass=ABCMeta):
    """Base class for attribute converters."""

    @abstractclassmethod
    def create_default(cls):
        """Create a default value for an attribute."""
        raise NotImplementedError(common.OVERRIDE_MESSAGE)

    @abstractclassmethod
    def to_value(cls, data):
        """Convert loaded data to an attribute's value."""
        raise NotImplementedError(common.OVERRIDE_MESSAGE)

    @abstractclassmethod
    def to_data(cls, value):
        """Convert an attribute to data optimized for dumping."""
        raise NotImplementedError(common.OVERRIDE_MESSAGE)


class Container(Mappable, Converter, metaclass=ABCMeta):
    """Base class for mutable attribute converters."""

    @classmethod
    def create_default(cls):
        return cls.__new__(cls)

    @classmethod
    def to_value(cls, data):
        value = cls.create_default()
        value.update_value(data, strict=False)
        return value

    @abstractmethod
    def update_value(self, data, strict):  # pragma: no cover (abstract method)
        """Update the attribute's value from loaded data."""
        raise NotImplementedError(common.OVERRIDE_MESSAGE)

    def format_data(self):
        """Format the attribute to data optimized for dumping."""
        return self.to_data(self)