Source code for bokeh.core.property.nullable
#-----------------------------------------------------------------------------
# Copyright (c) 2012 - 2022, Anaconda, Inc., and Bokeh Contributors.
# All rights reserved.
#
# The full license is in the file LICENSE.txt, distributed with this software.
#-----------------------------------------------------------------------------
""" Provide ``Nullable`` and ``NonNullable`` properties. """
#-----------------------------------------------------------------------------
# Boilerplate
#-----------------------------------------------------------------------------
from __future__ import annotations
import logging # isort:skip
log = logging.getLogger(__name__)
#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------
# Standard library imports
from typing import Any, TypeVar, Union
# Bokeh imports
from ...util.deprecation import deprecated
from ._sphinx import property_link, register_type_link, type_link
from .bases import (
Init,
Property,
SingleParameterizedProperty,
TypeOrInst,
)
from .required import Required
from .singletons import Undefined
#-----------------------------------------------------------------------------
# Globals and constants
#-----------------------------------------------------------------------------
__all__ = (
"NonNullable",
"Nullable",
)
T = TypeVar("T")
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# General API
#-----------------------------------------------------------------------------
[docs]class Nullable(SingleParameterizedProperty[Union[T, None]]):
""" A property accepting ``None`` or a value of some other type. """
def __init__(self, type_param: TypeOrInst[Property[T]], *, default: Init[T | None] = None, help: str | None = None) -> None:
super().__init__(type_param, default=default, help=help)
def transform(self, value: Any) -> T | None:
return None if value is None else super().transform(value)
def wrap(self, value: Any) -> Any:
return None if value is None else super().wrap(value)
def validate(self, value: Any, detail: bool = True) -> None:
if value is None:
return
try:
super().validate(value, detail=False)
except ValueError:
pass
else:
return
msg = "" if not detail else f"expected either None or a value of type {self.type_param}, got {value!r}"
raise ValueError(msg)
[docs]class NonNullable(Required[T]):
"""
A property accepting a value of some other type while having undefined default.
.. deprecated:: 3.0.0
Use ``bokeh.core.property.required.Required`` instead.
"""
def __init__(self, type_param: TypeOrInst[Property[T]], *, default: Init[T] = Undefined, help: str | None = None) -> None:
deprecated((3, 0, 0), "NonNullable(Type)", "Required(Type)")
super().__init__(type_param, default=default, help=help)
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# Dev API
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#-----------------------------------------------------------------------------
# Private API
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#-----------------------------------------------------------------------------
# Code
#-----------------------------------------------------------------------------
@register_type_link(Nullable)
@register_type_link(NonNullable)
def _sphinx_type_link(obj: SingleParameterizedProperty[Any]) -> str:
return f"{property_link(obj)}({type_link(obj.type_param)})"