Source code for bokeh.core.property.struct
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# Copyright (c) Anaconda, Inc. All rights reserved.
#
# Powered by the Bokeh Development Team.
#
# The full license is in the file LICENSE.txt, distributed with this software.
#-----------------------------------------------------------------------------
""" Provide the Struct property.
"""
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# Boilerplate
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from __future__ import annotations
import logging # isort:skip
log = logging.getLogger(__name__)
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# Imports
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# Standard library imports
from types import SimpleNamespace
from typing import Any, Generic, TypeVar
# Bokeh imports
from .bases import ParameterizedProperty, Property
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# Globals and constants
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__all__ = (
'Struct',
)
T = TypeVar("T")
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# General API
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class Optional(Generic[T]):
def __init__(self, type_param: Property[T]):
self.type_param = type_param
[docs]
class Struct(ParameterizedProperty[T]):
""" Accept values that are structures.
"""
_fields: dict[str, Property[Any]]
_optional: set[str]
def __init__(self, **fields: Any) -> None:
default = fields.pop("default", None)
help = fields.pop("help", None)
if not fields:
raise ValueError("expected specification of fields, got nothing")
self._fields = {}
self._optional = set()
for name, type in fields.items():
if isinstance(type, Optional):
self._optional.add(name)
type = type.type_param
self._fields[name] = self._validate_type_param(type, help_allowed=True) # XXX
super().__init__(default=default, help=help)
def __eq__(self, other: object) -> bool:
if isinstance(other, self.__class__):
return super().__eq__(other) and self._fields == other._fields and self._optional == other._optional
else:
return False
@property
def type_params(self):
return list(self._fields.values())
def validate(self, value: Any, detail: bool = True):
super().validate(value, detail)
if isinstance(value, SimpleNamespace):
value = value.__dict__
if isinstance(value, dict) and len(value) <= len(self._fields):
for name, type in self._fields.items():
if name not in value:
if name not in self._optional:
break
elif not type.is_valid(value[name]):
break
else:
for name in value.keys():
if name not in self._fields:
break
else:
return
msg = "" if not detail else f"expected an element of {self}, got {value!r}"
raise ValueError(msg)
def __str__(self) -> str:
class_name = self.__class__.__name__
fields = ", ".join(f"{name}={typ}" for name, typ in self._fields.items())
return f"{class_name}({fields})"
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# Dev API
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class struct(SimpleNamespace):
"""
Allow access unnamed struct with attributes and keys.
.. note::
This feature is experimental and may change in the short term.
"""
def __getitem__(self, key: str) -> Any:
return getattr(self, key)
def __setitem__(self, key: str, val: Any) -> None:
setattr(self, key, val)
def __delitem__(self, key: str) -> None:
delattr(self, key)
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# Private API
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# Code
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