python-telegram-bot/telegram/ext/typehandler.py

88 lines
3.4 KiB
Python

#!/usr/bin/env python
#
# A library that provides a Python interface to the Telegram Bot API
# Copyright (C) 2015-2022
# Leandro Toledo de Souza <devs@python-telegram-bot.org>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser Public License for more details.
#
# You should have received a copy of the GNU Lesser Public License
# along with this program. If not, see [http://www.gnu.org/licenses/].
"""This module contains the TypeHandler class."""
from typing import Callable, Type, TypeVar, Union
from telegram.utils.defaultvalue import DefaultValue, DEFAULT_FALSE
from .handler import Handler
from .utils.types import CCT
RT = TypeVar('RT')
UT = TypeVar('UT')
class TypeHandler(Handler[UT, CCT]):
"""Handler class to handle updates of custom types.
Warning:
When setting ``run_async`` to :obj:`True`, you cannot rely on adding custom
attributes to :class:`telegram.ext.CallbackContext`. See its docs for more info.
Args:
type (:obj:`type`): The ``type`` of updates this handler should process, as
determined by ``isinstance``
callback (:obj:`callable`): The callback function for this handler. Will be called when
:attr:`check_update` has determined that an update should be processed by this handler.
Callback signature: ``def callback(update: Update, context: CallbackContext)``
The return value of the callback is usually ignored except for the special case of
:class:`telegram.ext.ConversationHandler`.
strict (:obj:`bool`, optional): Use ``type`` instead of ``isinstance``.
Default is :obj:`False`
run_async (:obj:`bool`): Determines whether the callback will run asynchronously.
Defaults to :obj:`False`.
Attributes:
type (:obj:`type`): The ``type`` of updates this handler should process.
callback (:obj:`callable`): The callback function for this handler.
strict (:obj:`bool`): Use ``type`` instead of ``isinstance``. Default is :obj:`False`.
run_async (:obj:`bool`): Determines whether the callback will run asynchronously.
"""
__slots__ = ('type', 'strict')
def __init__(
self,
type: Type[UT], # pylint: disable=redefined-builtin
callback: Callable[[UT, CCT], RT],
strict: bool = False,
run_async: Union[bool, DefaultValue] = DEFAULT_FALSE,
):
super().__init__(
callback,
run_async=run_async,
)
self.type = type # pylint: disable=assigning-non-slot
self.strict = strict # pylint: disable=assigning-non-slot
def check_update(self, update: object) -> bool:
"""Determines whether an update should be passed to this handlers :attr:`callback`.
Args:
update (:obj:`object`): Incoming update.
Returns:
:obj:`bool`
"""
if not self.strict:
return isinstance(update, self.type)
return type(update) is self.type # pylint: disable=unidiomatic-typecheck