# -*- coding: utf-8 -*-
"""
The MIT License (MIT)
Copyright (c) 2015-2017 Rapptz
Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the "Software"),
to deal in the Software without restriction, including without limitation
the rights to use, copy, modify, merge, publish, distribute, sublicense,
and/or sell copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.
"""
import asyncio
import discord
import inspect
import importlib
import sys
import traceback
import re
from .core import GroupMixin, Command, command
from .view import StringView
from .context import Context
from .errors import CommandNotFound, CommandError
from .formatter import HelpFormatter
def when_mentioned(bot, msg):
"""A callable that implements a command prefix equivalent
to being mentioned, e.g. ``@bot ``."""
guild = msg.guild
if guild is not None:
return '{0.me.mention} '.format(guild)
return '{0.user.mention} '.format(bot)
def when_mentioned_or(*prefixes):
"""A callable that implements when mentioned or other prefixes provided.
Example
--------
.. code-block:: python
bot = commands.Bot(command_prefix=commands.when_mentioned_or('!'))
See Also
----------
:func:`when_mentioned`
"""
def inner(bot, msg):
r = list(prefixes)
r.append(when_mentioned(bot, msg))
return r
return inner
_mentions_transforms = {
'@everyone': '@\u200beveryone',
'@here': '@\u200bhere'
}
_mention_pattern = re.compile('|'.join(_mentions_transforms.keys()))
@asyncio.coroutine
def _default_help_command(ctx, *commands : str):
"""Shows this message."""
bot = ctx.bot
destination = ctx.message.author if bot.pm_help else ctx.message.channel
def repl(obj):
return _mentions_transforms.get(obj.group(0), '')
# help by itself just lists our own commands.
if len(commands) == 0:
pages = bot.formatter.format_help_for(ctx, bot)
elif len(commands) == 1:
# try to see if it is a cog name
name = _mention_pattern.sub(repl, commands[0])
command = None
if name in bot.cogs:
command = bot.cogs[name]
else:
command = bot.commands.get(name)
if command is None:
yield from destination.send(bot.command_not_found.format(name))
return
pages = bot.formatter.format_help_for(ctx, command)
else:
name = _mention_pattern.sub(repl, commands[0])
command = bot.commands.get(name)
if command is None:
yield from destination.send(bot.command_not_found.format(name))
return
for key in commands[1:]:
try:
key = _mention_pattern.sub(repl, key)
command = command.commands.get(key)
if command is None:
yield from destination.send(bot.command_not_found.format(key))
return
except AttributeError:
yield from destination.send(bot.command_has_no_subcommands.format(command, key))
return
pages = bot.formatter.format_help_for(ctx, command)
if bot.pm_help is None:
characters = sum(map(lambda l: len(l), pages))
# modify destination based on length of pages.
if characters > 1000:
destination = ctx.message.author
for page in pages:
yield from destination.send(page)
class BotBase(GroupMixin):
def __init__(self, command_prefix, formatter=None, description=None, pm_help=False, **options):
super().__init__(**options)
self.command_prefix = command_prefix
self.extra_events = {}
self.cogs = {}
self.extensions = {}
self._checks = []
self._before_invoke = None
self._after_invoke = None
self.description = inspect.cleandoc(description) if description else ''
self.pm_help = pm_help
self.command_not_found = options.pop('command_not_found', 'No command called "{}" found.')
self.command_has_no_subcommands = options.pop('command_has_no_subcommands', 'Command {0.name} has no subcommands.')
if options.pop('self_bot', False):
self._skip_check = lambda x, y: x != y
else:
self._skip_check = lambda x, y: x == y
self.help_attrs = options.pop('help_attrs', {})
self.help_attrs['pass_context'] = True
if 'name' not in self.help_attrs:
self.help_attrs['name'] = 'help'
if formatter is not None:
if not isinstance(formatter, HelpFormatter):
raise discord.ClientException('Formatter must be a subclass of HelpFormatter')
self.formatter = formatter
else:
self.formatter = HelpFormatter()
# pay no mind to this ugliness.
self.command(**self.help_attrs)(_default_help_command)
# internal helpers
def dispatch(self, event_name, *args, **kwargs):
super().dispatch(event_name, *args, **kwargs)
ev = 'on_' + event_name
for event in self.extra_events.get(ev, []):
coro = self._run_event(event, event_name, *args, **kwargs)
discord.compat.create_task(coro, loop=self.loop)
@asyncio.coroutine
def close(self):
for extension in tuple(self.extensions):
try:
self.unload_extension(extension)
except:
pass
for cog in tuple(self.cogs):
try:
self.remove_cog(cog)
except:
pass
yield from super().close()
@asyncio.coroutine
def on_command_error(self, exception, context):
"""|coro|
The default command error handler provided by the bot.
By default this prints to ``sys.stderr`` however it could be
overridden to have a different implementation.
This only fires if you do not specify any listeners for command error.
"""
if self.extra_events.get('on_command_error', None):
return
if hasattr(context.command, "on_error"):
return
print('Ignoring exception in command {}'.format(context.command), file=sys.stderr)
traceback.print_exception(type(exception), exception, exception.__traceback__, file=sys.stderr)
# global check registration
def check(self, func):
"""A decorator that adds a global check to the bot.
A global check is similar to a :func:`check` that is applied
on a per command basis except it is run before any command checks
have been verified and applies to every command the bot has.
.. warning::
This function must be a *regular* function and not a coroutine.
Similar to a command :func:`check`\, this takes a single parameter
of type :class:`Context` and can only raise exceptions derived from
:exc:`CommandError`.
Example
---------
.. code-block:: python
@bot.check
def whitelist(ctx):
return ctx.message.author.id in my_whitelist
"""
self.add_check(func)
return func
def add_check(self, func):
"""Adds a global check to the bot.
This is the non-decorator interface to :meth:`check`.
Parameters
-----------
func
The function that was used as a global check.
"""
self._checks.append(func)
def remove_check(self, func):
"""Removes a global check from the bot.
This function is idempotent and will not raise an exception
if the function is not in the global checks.
Parameters
-----------
func
The function to remove from the global checks.
"""
try:
self._checks.remove(func)
except ValueError:
pass
def can_run(self, ctx):
return all(f(ctx) for f in self._checks)
def before_invoke(self, coro):
"""A decorator that registers a coroutine as a pre-invoke hook.
A pre-invoke hook is called directly before the command is
called. This makes it a useful function to set up database
connections or any type of set up required.
This pre-invoke hook takes a sole parameter, a :class:`Context`.
.. note::
The :meth:`before_invoke` and :meth:`after_invoke` hooks are
only called if all checks and argument parsing procedures pass
without error. If any check or argument parsing procedures fail
then the hooks are not called.
Parameters
-----------
coro
The coroutine to register as the pre-invoke hook.
Raises
-------
discord.ClientException
The coroutine is not actually a coroutine.
"""
if not asyncio.iscoroutinefunction(coro):
raise discord.ClientException('The error handler must be a coroutine.')
self._before_invoke = coro
return coro
def after_invoke(self, coro):
"""A decorator that registers a coroutine as a post-invoke hook.
A post-invoke hook is called directly after the command is
called. This makes it a useful function to clean-up database
connections or any type of clean up required.
This post-invoke hook takes a sole parameter, a :class:`Context`.
.. note::
Similar to :meth:`before_invoke`\, this is not called unless
checks and argument parsing procedures succeed. This hook is,
however, **always** called regardless of the internal command
callback raising an error (i.e. :exc:`CommandInvokeError`\).
This makes it ideal for clean-up scenarios.
Parameters
-----------
coro
The coroutine to register as the post-invoke hook.
Raises
-------
discord.ClientException
The coroutine is not actually a coroutine.
"""
if not asyncio.iscoroutinefunction(coro):
raise discord.ClientException('The error handler must be a coroutine.')
self._after_invoke = coro
return coro
# listener registration
def add_listener(self, func, name=None):
"""The non decorator alternative to :meth:`listen`.
Parameters
-----------
func : coroutine
The extra event to listen to.
name : Optional[str]
The name of the command to use. Defaults to ``func.__name__``.
Example
--------
.. code-block:: python
async def on_ready(): pass
async def my_message(message): pass
bot.add_listener(on_ready)
bot.add_listener(my_message, 'on_message')
"""
name = func.__name__ if name is None else name
if not asyncio.iscoroutinefunction(func):
raise discord.ClientException('Listeners must be coroutines')
if name in self.extra_events:
self.extra_events[name].append(func)
else:
self.extra_events[name] = [func]
def remove_listener(self, func, name=None):
"""Removes a listener from the pool of listeners.
Parameters
-----------
func
The function that was used as a listener to remove.
name
The name of the event we want to remove. Defaults to
``func.__name__``.
"""
name = func.__name__ if name is None else name
if name in self.extra_events:
try:
self.extra_events[name].remove(func)
except ValueError:
pass
def listen(self, name=None):
"""A decorator that registers another function as an external
event listener. Basically this allows you to listen to multiple
events from different places e.g. such as :func:`discord.on_ready`
The functions being listened to must be a coroutine.
Example
--------
.. code-block:: python
@bot.listen()
async def on_message(message):
print('one')
# in some other file...
@bot.listen('on_message')
async def my_message(message):
print('two')
Would print one and two in an unspecified order.
Raises
-------
discord.ClientException
The function being listened to is not a coroutine.
"""
def decorator(func):
self.add_listener(func, name)
return func
return decorator
# cogs
def add_cog(self, cog):
"""Adds a "cog" to the bot.
A cog is a class that has its own event listeners and commands.
They are meant as a way to organize multiple relevant commands
into a singular class that shares some state or no state at all.
The cog can also have a ``__global_check`` member function that allows
you to define a global check. See :meth:`check` for more info.
More information will be documented soon.
Parameters
-----------
cog
The cog to register to the bot.
"""
self.cogs[type(cog).__name__] = cog
try:
check = getattr(cog, '_{.__class__.__name__}__global_check'.format(cog))
except AttributeError:
pass
else:
self.add_check(check)
members = inspect.getmembers(cog)
for name, member in members:
# register commands the cog has
if isinstance(member, Command):
if member.parent is None:
self.add_command(member)
continue
# register event listeners the cog has
if name.startswith('on_'):
self.add_listener(member)
def get_cog(self, name):
"""Gets the cog instance requested.
If the cog is not found, ``None`` is returned instead.
Parameters
-----------
name : str
The name of the cog you are requesting.
"""
return self.cogs.get(name)
def remove_cog(self, name):
"""Removes a cog from the bot.
All registered commands and event listeners that the
cog has registered will be removed as well.
If no cog is found then ``None`` is returned, otherwise
the cog instance that is being removed is returned.
If the cog defines a special member function named ``__unload``
then it is called when removal has completed. This function
**cannot** be a coroutine. It must be a regular function.
Parameters
-----------
name : str
The name of the cog to remove.
"""
cog = self.cogs.pop(name, None)
if cog is None:
return cog
members = inspect.getmembers(cog)
for name, member in members:
# remove commands the cog has
if isinstance(member, Command):
if member.parent is None:
self.remove_command(member.name)
continue
# remove event listeners the cog has
if name.startswith('on_'):
self.remove_listener(member)
try:
check = getattr(cog, '_{0.__class__.__name__}__global_check'.format(cog))
except AttributeError:
pass
else:
self.remove_check(check)
unloader_name = '_{0.__class__.__name__}__unload'.format(cog)
try:
unloader = getattr(cog, unloader_name)
except AttributeError:
pass
else:
unloader()
del cog
# extensions
def load_extension(self, name):
if name in self.extensions:
return
lib = importlib.import_module(name)
if not hasattr(lib, 'setup'):
del lib
del sys.modules[name]
raise discord.ClientException('extension does not have a setup function')
lib.setup(self)
self.extensions[name] = lib
def unload_extension(self, name):
lib = self.extensions.get(name)
if lib is None:
return
# find all references to the module
# remove the cogs registered from the module
for cogname, cog in self.cogs.copy().items():
if inspect.getmodule(cog) is lib:
self.remove_cog(cogname)
# first remove all the commands from the module
for command in self.commands.copy().values():
if command.module is lib:
command.module = None
if isinstance(command, GroupMixin):
command.recursively_remove_all_commands()
self.remove_command(command.name)
# then remove all the listeners from the module
for event_list in self.extra_events.copy().values():
remove = []
for index, event in enumerate(event_list):
if inspect.getmodule(event) is lib:
remove.append(index)
for index in reversed(remove):
del event_list[index]
try:
func = getattr(lib, 'teardown')
except AttributeError:
pass
else:
try:
func(self)
except:
pass
finally:
# finally remove the import..
del lib
del self.extensions[name]
del sys.modules[name]
# command processing
@asyncio.coroutine
def get_prefix(self, message):
"""|coro|
Retrieves the prefix the bot is listening to
with the message as a context.
Parameters
-----------
message: :class:`discord.Message`
The message context to get the prefix of.
Returns
--------
Union[List[str], str]
A list of prefixes or a single prefix that the bot is
listening for.
"""
prefix = self.command_prefix
if callable(prefix):
ret = prefix(self, message)
if asyncio.iscoroutine(ret):
ret = yield from ret
return ret
else:
return prefix
@asyncio.coroutine
def get_context(self, message, *, cls=Context):
"""|coro|
Returns the invocation context from the message.
This is a more low-level counter-part for :meth:`process_message`
to allow users more fine grained control over the processing.
The returned context is not guaranteed to be a valid invocation
context, :attr:`Context.valid` must be checked to make sure it is.
If the context is not valid then it is not a valid candidate to be
invoked under :meth:`invoke`.
Parameters
-----------
message: :class:`discord.Message`
The message to get the invocation context from.
cls: type
The factory class that will be used to create the context.
By default, this is :class:`Context`. Should a custom
class be provided, it must be similar enough to :class:`Context`\'s
interface.
Returns
--------
:class:`Context`
The invocation context. The type of this can change via the
``cls`` parameter.
"""
view = StringView(message.content)
ctx = cls(prefix=None, view=view, bot=self, message=message)
if self._skip_check(message.author.id, self.user.id):
return ctx
prefix = yield from self.get_prefix(message)
invoked_prefix = prefix
if not isinstance(prefix, (tuple, list)):
if not view.skip_string(prefix):
return ctx
else:
invoked_prefix = discord.utils.find(view.skip_string, prefix)
if invoked_prefix is None:
return ctx
invoker = view.get_word()
ctx.invoked_with = invoker
ctx.prefix = invoked_prefix
ctx.command = self.commands.get(invoker)
return ctx
@asyncio.coroutine
def invoke(self, ctx):
"""|coro|
Invokes the command given under the invocation context and
handles all the internal event dispatch mechanisms.
Parameters
-----------
ctx: :class:`Context`
The invocation context to invoke.
"""
if ctx.command is not None:
self.dispatch('command', ctx)
try:
yield from ctx.command.invoke(ctx)
except CommandError as e:
yield from ctx.command.dispatch_error(e, ctx)
else:
ctx.command_failed = False
self.dispatch('command_completion', ctx)
elif ctx.invoked_with:
exc = CommandNotFound('Command "{}" is not found'.format(ctx.invoked_with))
self.dispatch('command_error', exc, ctx)
@asyncio.coroutine
def process_commands(self, message):
"""|coro|
This function processes the commands that have been registered
to the bot and other groups. Without this coroutine, none of the
commands will be triggered.
By default, this coroutine is called inside the :func:`on_message`
event. If you choose to override the :func:`on_message` event, then
you should invoke this coroutine as well.
This is built using other low level tools, and is equivalent to a
call to :meth:`get_context` followed by a call to :meth:`invoke`.
Parameters
-----------
message : discord.Message
The message to process commands for.
"""
ctx = yield from self.get_context(message)
yield from self.invoke(ctx)
@asyncio.coroutine
def on_message(self, message):
yield from self.process_commands(message)
class Bot(BotBase, discord.Client):
"""Represents a discord bot.
This class is a subclass of :class:`discord.Client` and as a result
anything that you can do with a :class:`discord.Client` you can do with
this bot.
This class also subclasses :class:`GroupMixin` to provide the functionality
to manage commands.
Attributes
-----------
command_prefix
The command prefix is what the message content must contain initially
to have a command invoked. This prefix could either be a string to
indicate what the prefix should be, or a callable that takes in the bot
as its first parameter and :class:`discord.Message` as its second
parameter and returns the prefix. This is to facilitate "dynamic"
command prefixes. This callable can be either a regular function or
a coroutine.
The command prefix could also be a list or a tuple indicating that
multiple checks for the prefix should be used and the first one to
match will be the invocation prefix. You can get this prefix via
:attr:`Context.prefix`.
description : str
The content prefixed into the default help message.
self_bot : bool
If ``True``, the bot will only listen to commands invoked by itself rather
than ignoring itself. If ``False`` (the default) then the bot will ignore
itself. This cannot be changed once initialised.
formatter : :class:`HelpFormatter`
The formatter used to format the help message. By default, it uses a
the :class:`HelpFormatter`. Check it for more info on how to override it.
If you want to change the help command completely (add aliases, etc) then
a call to :meth:`remove_command` with 'help' as the argument would do the
trick.
pm_help : Optional[bool]
A tribool that indicates if the help command should PM the user instead of
sending it to the channel it received it from. If the boolean is set to
``True``, then all help output is PM'd. If ``False``, none of the help
output is PM'd. If ``None``, then the bot will only PM when the help
message becomes too long (dictated by more than 1000 characters).
Defaults to ``False``.
help_attrs : dict
A dictionary of options to pass in for the construction of the help command.
This allows you to change the command behaviour without actually changing
the implementation of the command. The attributes will be the same as the
ones passed in the :class:`Command` constructor. Note that ``pass_context``
will always be set to ``True`` regardless of what you pass in.
command_not_found : str
The format string used when the help command is invoked with a command that
is not found. Useful for i18n. Defaults to ``"No command called {} found."``.
The only format argument is the name of the command passed.
command_has_no_subcommands : str
The format string used when the help command is invoked with requests for a
subcommand but the command does not have any subcommands. Defaults to
``"Command {0.name} has no subcommands."``. The first format argument is the
:class:`Command` attempted to get a subcommand and the second is the name.
"""
pass
class AutoShardedBot(BotBase, discord.AutoShardedClient):
"""This is similar to :class:`Bot` except that it is derived from
:class:`discord.AutoShardedClient` instead.
"""
pass