Source code for bokeh.core.property.either
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# Copyright (c) 2012 - 2018, Anaconda, Inc. All rights reserved.
#
# Powered by the Bokeh Development Team.
#
# The full license is in the file LICENSE.txt, distributed with this software.
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''' Provide the Either property.
The Either property is used to construct properties that an accept any of
multiple possible types.
'''
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# Boilerplate
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from __future__ import absolute_import, division, print_function, unicode_literals
import logging
log = logging.getLogger(__name__)
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# Imports
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# Standard library imports
# External imports
# Bokeh imports
from ...util.string import nice_join
from .bases import DeserializationError, ParameterizedProperty
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# Globals and constants
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__all__ = (
'Either',
)
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# General API
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[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, **kwargs):
self._type_params = list(map(self._validate_type_param, (tp1, tp2) + type_params))
help = kwargs.get("help")
def choose_default():
return self._type_params[0]._raw_default()
default = kwargs.get("default", choose_default)
super(Either, self).__init__(default=default, help=help)
self.alternatives = []
for tp in self._type_params:
self.alternatives.extend(tp.alternatives)
# TODO (bev) get rid of this?
def __or__(self, other):
return self.__class__(*(self.type_params + [other]), default=self._default, help=self.help)
def __str__(self):
return "%s(%s)" % (self.__class__.__name__, ", ".join(map(str, self.type_params)))
@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)
except DeserializationError:
pass
else:
raise DeserializationError("%s couldn't deserialize %s" % (self, json))
def transform(self, value):
for param in self.type_params:
try:
return param.transform(value)
except ValueError:
pass
raise ValueError("Could not transform %r" % value)
def validate(self, value, detail=True):
super(Either, self).validate(value, detail)
if not (value is None or any(param.is_valid(value) for param in self.type_params)):
msg = "" if not detail else "expected an element of either %s, got %r" % (nice_join(self.type_params), value)
raise ValueError(msg)
# TODO (bev) implement this
# def _may_have_unstable_default(self):
# return any(tp._may_have_unstable_default() for tp in self.type_params)
def _sphinx_type(self):
return self._sphinx_prop_link() + "( %s )" % ", ".join(x._sphinx_type() for x in self.type_params)
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# Dev API
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# Private API
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# Code
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