Source code for bokeh.core.property.constraints
#-----------------------------------------------------------------------------
# Copyright (c) Anaconda, Inc., and Bokeh Contributors.
# All rights reserved.
#
# The full license is in the file LICENSE.txt, distributed with this software.
#-----------------------------------------------------------------------------
""" Various ways for constraining values of other properties.
"""
#-----------------------------------------------------------------------------
# Boilerplate
#-----------------------------------------------------------------------------
from __future__ import annotations
import logging # isort:skip
log = logging.getLogger(__name__)
#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------
# Standard library imports
from typing import Any, TypeVar
# Bokeh imports
from ._sphinx import property_link, register_type_link, type_link
from .bases import (
Init,
Property,
SingleParameterizedProperty,
TypeOrInst,
)
from .singletons import Intrinsic
#-----------------------------------------------------------------------------
# Globals and constants
#-----------------------------------------------------------------------------
__all__ = (
"TypeOfAttr",
)
T = TypeVar("T")
#-----------------------------------------------------------------------------
# General API
#-----------------------------------------------------------------------------
[docs]
class TypeOfAttr(SingleParameterizedProperty[T]):
""" Allows to check if an attribute of an object satisfies the
given type or a collection of types.
"""
def __init__(
self,
type_param: TypeOrInst[Property[T]],
name: str,
type: TypeOrInst[Property[Any]],
*,
default: Init[T] = Intrinsic,
help: str | None = None,
) -> None:
super().__init__(type_param, default=default, help=help)
self._query_name = name
self._query_type = self._validate_type_param(type)
def __call__(self, *, default: Init[T] = Intrinsic, help: str | None = None) -> TypeOfAttr[T]:
""" Clone this property and allow to override ``default`` and ``help``. """
default = self._default if default is Intrinsic else default
help = self._help if help is None else help
prop = self.__class__(self.type_param, self._query_name, self._query_type, default=default, help=help)
prop.alternatives = list(self.alternatives)
prop.assertions = list(self.assertions)
return prop
def __str__(self) -> str:
class_name = self.__class__.__name__
return f"{class_name}({self.type_param}, {self._query_name!r}, {self._query_type})"
def validate(self, value: Any, detail: bool = True) -> None:
super().validate(value, detail)
name = self._query_name
type = self._query_type
try:
attr = getattr(value, name)
except AttributeError:
raise ValueError(f"expected {value!r} to have an attribute '{name}'" if detail else "")
if type.is_valid(attr):
return
raise ValueError(f"expected {value!r} to have an attribute {name!r} of type {type}" if detail else "")
#-----------------------------------------------------------------------------
# Dev API
#-----------------------------------------------------------------------------
#-----------------------------------------------------------------------------
# Private API
#-----------------------------------------------------------------------------
#-----------------------------------------------------------------------------
# Code
#-----------------------------------------------------------------------------
@register_type_link(TypeOfAttr)
def _sphinx_type_link(obj: SingleParameterizedProperty[Any]) -> str:
return f"{property_link(obj)}({type_link(obj.type_param)})"