python-telegram-bot/telegram/ext/conversationhandler.py
Joscha Götzer ac59f2f37c Added methods to generate the original markdown/html string from entities contained in Message (#507)
* Added methods to generate the original markdown/html formatted string from the entities contained in an update

* Added

* Moved the html/markdown parsing methods to `Message`

* Moved extract_* methods from helpers to the appropriate location

* Refactored text_markdown and text_html

* Refactored text_markdown and text_html for efficiency

* Fixed method call in conversationhandler

* Fixed method call in handler

* Fixed `make test` command on windows systems

* Improved method documentation
2017-01-20 20:13:58 +01:00

206 lines
8.5 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.promise import Promise
class ConversationHandler(Handler):
"""
A handler to hold a conversation with a single user by managing four collections of other
handlers. Note that neither posts in Telegram Channels, nor group interactions with multiple
users are managed by instances of this class.
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):
# Ignore messages in channels
if not isinstance(update, Update) or update.channel_post:
return False
chat, user = update.extract_chat_and_user()
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