python-telegram-bot/telegram/ext/conversationhandler.py
Jannes Höke 10bdf8212c Add pass_user_data and pass_chat_data to Handler (#436)
* initial commit for user_data

* add chat_data and use defaultdict

* fix chat_data copy-paste error

* add test for user_data and chat_data

* fix case where chat is None

* remove braces from import line
2016-10-25 19:28:34 +02:00

204 lines
8.3 KiB
Python

#!/usr/bin/env python
#
# A library that provides a Python interface to the Telegram Bot API
# Copyright (C) 2015-2016
# 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 ConversationHandler """
import logging
from telegram import Update
from telegram.ext import Handler
from telegram.utils.helpers import extract_chat_and_user
from telegram.utils.promise import Promise
class ConversationHandler(Handler):
"""
A handler to hold a conversation with a user by managing four collections of other handlers.
The first collection, a ``list`` named ``entry_points``, is used to initiate the conversation,
for example with a ``CommandHandler`` or ``RegexHandler``.
The second collection, a ``dict`` named ``states``, contains the different conversation steps
and one or more associated handlers that should be used if the user sends a message when the
conversation with them is currently in that state. You will probably use mostly
``MessageHandler`` and ``RegexHandler`` here.
The third collection, a ``list`` named ``fallbacks``, is used if the user is currently in a
conversation but the state has either no associated handler or the handler that is associated
to the state is inappropriate for the update, for example if the update contains a command, but
a regular text message is expected. You could use this for a ``/cancel`` command or to let the
user know their message was not recognized.
The fourth, optional collection of handlers, a ``list`` named ``timed_out_behavior`` is used if
the wait for ``run_async`` takes longer than defined in ``run_async_timeout``. For example,
you can let the user know that they should wait for a bit before they can continue.
To change the state of conversation, the callback function of a handler must return the new
state after responding to the user. If it does not return anything (returning ``None`` by
default), the state will not change. To end the conversation, the callback function must
return ``CallbackHandler.END`` or ``-1``.
Args:
entry_points (list): A list of ``Handler`` objects that can trigger the start of the
conversation. The first handler which ``check_update`` method returns ``True`` will be
used. If all return ``False``, the update is not handled.
states (dict): A ``dict[object: list[Handler]]`` that defines the different states of
conversation a user can be in and one or more associated ``Handler`` objects that
should be used in that state. The first handler which ``check_update`` method returns
``True`` will be used.
fallbacks (list): A list of handlers that might be used if the user is in a conversation,
but every handler for their current state returned ``False`` on ``check_update``.
The first handler which ``check_update`` method returns ``True`` will be used. If all
return ``False``, the update is not handled.
allow_reentry (Optional[bool]): If set to ``True``, a user that is currently in a
conversation can restart the conversation by triggering one of the entry points.
run_async_timeout (Optional[float]): If the previous handler for this user was running
asynchronously using the ``run_async`` decorator, it might not be finished when the
next message arrives. This timeout defines how long the conversation handler should
wait for the next state to be computed. The default is ``None`` which means it will
wait indefinitely.
timed_out_behavior (Optional[list]): A list of handlers that might be used if
the wait for ``run_async`` timed out. The first handler which ``check_update`` method
returns ``True`` will be used. If all return ``False``, the update is not handled.
"""
END = -1
def __init__(self,
entry_points,
states,
fallbacks,
allow_reentry=False,
run_async_timeout=None,
timed_out_behavior=None):
self.entry_points = entry_points
""":type: list[telegram.ext.Handler]"""
self.states = states
""":type: dict[str: telegram.ext.Handler]"""
self.fallbacks = fallbacks
""":type: list[telegram.ext.Handler]"""
self.allow_reentry = allow_reentry
self.run_async_timeout = run_async_timeout
self.timed_out_behavior = timed_out_behavior
""":type: list[telegram.ext.Handler]"""
self.conversations = dict()
""":type: dict[(int, int): str]"""
self.current_conversation = None
self.current_handler = None
self.logger = logging.getLogger(__name__)
def check_update(self, update):
if not isinstance(update, Update):
return False
chat, user = extract_chat_and_user(update)
key = (chat.id, user.id) if chat else (None, user.id)
state = self.conversations.get(key)
# Resolve promises
if isinstance(state, tuple) and len(state) is 2 and isinstance(state[1], Promise):
self.logger.debug('waiting for promise...')
old_state, new_state = state
new_state.result(timeout=self.run_async_timeout)
if new_state.done.is_set():
self.update_state(new_state.result(), key)
state = self.conversations.get(key)
else:
for candidate in (self.timed_out_behavior or []):
if candidate.check_update(update):
# Save the current user and the selected handler for handle_update
self.current_conversation = key
self.current_handler = candidate
return True
else:
return False
self.logger.debug('selecting conversation %s with state %s' % (str(key), str(state)))
handler = None
# Search entry points for a match
if state is None or self.allow_reentry:
for entry_point in self.entry_points:
if entry_point.check_update(update):
handler = entry_point
break
else:
if state is None:
return False
# Get the handler list for current state, if we didn't find one yet and we're still here
if state is not None and not handler:
handlers = self.states.get(state)
for candidate in (handlers or []):
if candidate.check_update(update):
handler = candidate
break
# Find a fallback handler if all other handlers fail
else:
for fallback in self.fallbacks:
if fallback.check_update(update):
handler = fallback
break
else:
return False
# Save the current user and the selected handler for handle_update
self.current_conversation = key
self.current_handler = handler
return True
def handle_update(self, update, dispatcher):
new_state = self.current_handler.handle_update(update, dispatcher)
self.update_state(new_state, self.current_conversation)
def update_state(self, new_state, key):
if new_state == self.END:
if key in self.conversations:
del self.conversations[key]
else:
pass
elif isinstance(new_state, Promise):
self.conversations[key] = (self.conversations.get(key), new_state)
elif new_state is not None:
self.conversations[key] = new_state