#-----------------------------------------------------------------------------
# Copyright (c) 2012 - 2021, Anaconda, Inc., and Bokeh Contributors.
# All rights reserved.
#
# The full license is in the file LICENSE.txt, distributed with this software.
#-----------------------------------------------------------------------------
""" Provide the Either property.
The Either property is used to construct properties that an accept any of
multiple possible types.
"""
#-----------------------------------------------------------------------------
# Boilerplate
#-----------------------------------------------------------------------------
from __future__ import annotations
import logging # isort:skip
log = logging.getLogger(__name__)
#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------
# Bokeh imports
from ...util.string import nice_join
from ._sphinx import property_link, register_type_link, type_link
from .bases import DeserializationError, ParameterizedProperty
from .singletons import Intrinsic
#-----------------------------------------------------------------------------
# Globals and constants
#-----------------------------------------------------------------------------
__all__ = (
'Either',
)
#-----------------------------------------------------------------------------
# General API
#-----------------------------------------------------------------------------
[docs]class Either(ParameterizedProperty):
""" Accept values according to a sequence of other property types.
Example:
.. code-block:: python
>>> class EitherModel(HasProps):
... prop = Either(Bool, Int, Auto)
...
>>> m = EitherModel()
>>> m.prop = True
>>> m.prop = 10
>>> m.prop = "auto"
>>> m.prop = 10.3 # ValueError !!
>>> m.prop = "foo" # ValueError !!
"""
def __init__(self, tp1, tp2, *type_params, default=Intrinsic, help=None, serialized=None, readonly=False) -> None:
type_params = list(map(self._validate_type_param, (tp1, tp2) + type_params))
default = default if default is not Intrinsic else type_params[0]._raw_default()
super().__init__(default=default, help=help, serialized=serialized, readonly=readonly)
self._type_params = type_params
for tp in self._type_params:
self.alternatives.extend(tp.alternatives)
def __str__(self) -> str:
class_name = self.__class__.__name__
item_types = ", ".join(str(x) for x in self.type_params)
return f"{class_name}({item_types})"
@property
def type_params(self):
return self._type_params
def from_json(self, json, *, models=None):
for tp in self.type_params:
try:
return tp.from_json(json, models=models)
except DeserializationError:
pass
raise DeserializationError(f"{self} couldn't deserialize {json}")
def transform(self, value):
for param in self.type_params:
try:
return param.transform(value)
except ValueError:
pass
raise ValueError("Could not transform {value!r}")
def validate(self, value, detail=True):
super().validate(value, detail)
if any(param.is_valid(value) for param in self.type_params):
return
msg = "" if not detail else f"expected an element of either {nice_join(self.type_params)}, got {value!r}"
raise ValueError(msg)
def wrap(self, value):
for tp in self.type_params:
value = tp.wrap(value)
return value
# TODO (bev) implement this
# def _may_have_unstable_default(self):
# return any(tp._may_have_unstable_default() for tp in self.type_params)
#-----------------------------------------------------------------------------
# Dev API
#-----------------------------------------------------------------------------
#-----------------------------------------------------------------------------
# Private API
#-----------------------------------------------------------------------------
#-----------------------------------------------------------------------------
# Code
#-----------------------------------------------------------------------------
@register_type_link(Either)
def _sphinx_type_link(obj):
subtypes = ", ".join(type_link(x) for x in obj.type_params)
return f"{property_link(obj)}({subtypes})"