"""
The MIT License (MIT)
Copyright (c) 2015-present 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.
"""
from __future__ import annotations
import inspect
import discord
from discord import app_commands
from discord.utils import maybe_coroutine, _to_kebab_case
from typing import (
Any,
Callable,
ClassVar,
Coroutine,
Dict,
Generator,
Iterable,
List,
Optional,
TYPE_CHECKING,
Sequence,
Tuple,
TypeVar,
Union,
)
from ._types import _BaseCommand, BotT
if TYPE_CHECKING:
from typing_extensions import Self
from discord.abc import Snowflake
from discord._types import ClientT
from .bot import BotBase
from .context import Context
from .core import Command
__all__ = (
'CogMeta',
'Cog',
'GroupCog',
)
FuncT = TypeVar('FuncT', bound=Callable[..., Any])
MISSING: Any = discord.utils.MISSING
class CogMeta(type):
"""A metaclass for defining a cog.
Note that you should probably not use this directly. It is exposed
purely for documentation purposes along with making custom metaclasses to intermix
with other metaclasses such as the :class:`abc.ABCMeta` metaclass.
For example, to create an abstract cog mixin class, the following would be done.
.. code-block:: python3
import abc
class CogABCMeta(commands.CogMeta, abc.ABCMeta):
pass
class SomeMixin(metaclass=abc.ABCMeta):
pass
class SomeCogMixin(SomeMixin, commands.Cog, metaclass=CogABCMeta):
pass
.. note::
When passing an attribute of a metaclass that is documented below, note
that you must pass it as a keyword-only argument to the class creation
like the following example:
.. code-block:: python3
class MyCog(commands.Cog, name='My Cog'):
pass
Attributes
-----------
name: :class:`str`
The cog name. By default, it is the name of the class with no modification.
description: :class:`str`
The cog description. By default, it is the cleaned docstring of the class.
.. versionadded:: 1.6
command_attrs: :class:`dict`
A list of attributes to apply to every command inside this cog. The dictionary
is passed into the :class:`Command` options at ``__init__``.
If you specify attributes inside the command attribute in the class, it will
override the one specified inside this attribute. For example:
.. code-block:: python3
class MyCog(commands.Cog, command_attrs=dict(hidden=True)):
@commands.command()
async def foo(self, ctx):
pass # hidden -> True
@commands.command(hidden=False)
async def bar(self, ctx):
pass # hidden -> False
group_name: Union[:class:`str`, :class:`~discord.app_commands.locale_str`]
The group name of a cog. This is only applicable for :class:`GroupCog` instances.
By default, it's the same value as :attr:`name`.
.. versionadded:: 2.0
group_description: Union[:class:`str`, :class:`~discord.app_commands.locale_str`]
The group description of a cog. This is only applicable for :class:`GroupCog` instances.
By default, it's the same value as :attr:`description`.
.. versionadded:: 2.0
group_nsfw: :class:`bool`
Whether the application command group is NSFW. This is only applicable for :class:`GroupCog` instances.
By default, it's ``False``.
.. versionadded:: 2.0
group_auto_locale_strings: :class:`bool`
If this is set to ``True``, then all translatable strings will implicitly
be wrapped into :class:`~discord.app_commands.locale_str` rather
than :class:`str`. Defaults to ``True``.
.. versionadded:: 2.0
group_extras: :class:`dict`
A dictionary that can be used to store extraneous data.
This is only applicable for :class:`GroupCog` instances.
The library will not touch any values or keys within this dictionary.
.. versionadded:: 2.1
"""
__cog_name__: str
__cog_description__: str
__cog_group_name__: Union[str, app_commands.locale_str]
__cog_group_description__: Union[str, app_commands.locale_str]
__cog_group_nsfw__: bool
__cog_group_auto_locale_strings__: bool
__cog_group_extras__: Dict[Any, Any]
__cog_settings__: Dict[str, Any]
__cog_commands__: List[Command[Any, ..., Any]]
__cog_app_commands__: List[Union[app_commands.Group, app_commands.Command[Any, ..., Any]]]
__cog_listeners__: List[Tuple[str, str]]
def __new__(cls, *args: Any, **kwargs: Any) -> Self:
name, bases, attrs = args
if any(issubclass(base, app_commands.Group) for base in bases):
raise TypeError(
'Cannot inherit from app_commands.Group with commands.Cog, consider using commands.GroupCog instead'
)
# If name='...' is given but not group_name='...' then name='...' is used for both.
# If neither is given then cog name is the class name but group name is kebab case
try:
cog_name = kwargs.pop('name')
except KeyError:
cog_name = name
try:
group_name = kwargs.pop('group_name')
except KeyError:
group_name = _to_kebab_case(name)
else:
group_name = kwargs.pop('group_name', cog_name)
attrs['__cog_settings__'] = kwargs.pop('command_attrs', {})
attrs['__cog_name__'] = cog_name
attrs['__cog_group_name__'] = group_name
attrs['__cog_group_nsfw__'] = kwargs.pop('group_nsfw', False)
attrs['__cog_group_auto_locale_strings__'] = kwargs.pop('group_auto_locale_strings', True)
attrs['__cog_group_extras__'] = kwargs.pop('group_extras', {})
description = kwargs.pop('description', None)
if description is None:
description = inspect.cleandoc(attrs.get('__doc__', ''))
attrs['__cog_description__'] = description
attrs['__cog_group_description__'] = kwargs.pop('group_description', description or '\u2026')
commands = {}
cog_app_commands = {}
listeners = {}
no_bot_cog = 'Commands or listeners must not start with cog_ or bot_ (in method {0.__name__}.{1})'
new_cls = super().__new__(cls, name, bases, attrs, **kwargs)
for base in reversed(new_cls.__mro__):
for elem, value in base.__dict__.items():
if elem in commands:
del commands[elem]
if elem in listeners:
del listeners[elem]
is_static_method = isinstance(value, staticmethod)
if is_static_method:
value = value.__func__
if isinstance(value, _BaseCommand):
if is_static_method:
raise TypeError(f'Command in method {base}.{elem!r} must not be staticmethod.')
if elem.startswith(('cog_', 'bot_')):
raise TypeError(no_bot_cog.format(base, elem))
commands[elem] = value
elif isinstance(value, (app_commands.Group, app_commands.Command)) and value.parent is None:
if is_static_method:
raise TypeError(f'Command in method {base}.{elem!r} must not be staticmethod.')
if elem.startswith(('cog_', 'bot_')):
raise TypeError(no_bot_cog.format(base, elem))
cog_app_commands[elem] = value
elif inspect.iscoroutinefunction(value):
try:
getattr(value, '__cog_listener__')
except AttributeError:
continue
else:
if elem.startswith(('cog_', 'bot_')):
raise TypeError(no_bot_cog.format(base, elem))
listeners[elem] = value
new_cls.__cog_commands__ = list(commands.values()) # this will be copied in Cog.__new__
new_cls.__cog_app_commands__ = list(cog_app_commands.values())
listeners_as_list = []
for listener in listeners.values():
for listener_name in listener.__cog_listener_names__:
# I use __name__ instead of just storing the value so I can inject
# the self attribute when the time comes to add them to the bot
listeners_as_list.append((listener_name, listener.__name__))
new_cls.__cog_listeners__ = listeners_as_list
return new_cls
def __init__(self, *args: Any, **kwargs: Any) -> None:
super().__init__(*args)
@classmethod
def qualified_name(cls) -> str:
return cls.__cog_name__
def _cog_special_method(func: FuncT) -> FuncT:
func.__cog_special_method__ = None
return func
class Cog(metaclass=CogMeta):
"""The base class that all cogs must inherit from.
A cog is a collection of commands, listeners, and optional state to
help group commands together. More information on them can be found on
the :ref:`ext_commands_cogs` page.
When inheriting from this class, the options shown in :class:`CogMeta`
are equally valid here.
"""
__cog_name__: str
__cog_description__: str
__cog_group_name__: Union[str, app_commands.locale_str]
__cog_group_description__: Union[str, app_commands.locale_str]
__cog_settings__: Dict[str, Any]
__cog_commands__: List[Command[Self, ..., Any]]
__cog_app_commands__: List[Union[app_commands.Group, app_commands.Command[Self, ..., Any]]]
__cog_listeners__: List[Tuple[str, str]]
__cog_is_app_commands_group__: ClassVar[bool] = False
__cog_app_commands_group__: Optional[app_commands.Group]
__discord_app_commands_error_handler__: Optional[
Callable[[discord.Interaction, app_commands.AppCommandError], Coroutine[Any, Any, None]]
]
def __new__(cls, *args: Any, **kwargs: Any) -> Self:
# For issue 426, we need to store a copy of the command objects
# since we modify them to inject `self` to them.
# To do this, we need to interfere with the Cog creation process.
self = super().__new__(cls)
cmd_attrs = cls.__cog_settings__
# Either update the command with the cog provided defaults or copy it.
# r.e type ignore, type-checker complains about overriding a ClassVar
self.__cog_commands__ = tuple(c._update_copy(cmd_attrs) for c in cls.__cog_commands__) # type: ignore
lookup = {cmd.qualified_name: cmd for cmd in self.__cog_commands__}
# Register the application commands
children: List[Union[app_commands.Group, app_commands.Command[Self, ..., Any]]] = []
if cls.__cog_is_app_commands_group__:
group = app_commands.Group(
name=cls.__cog_group_name__,
description=cls.__cog_group_description__,
nsfw=cls.__cog_group_nsfw__,
auto_locale_strings=cls.__cog_group_auto_locale_strings__,
parent=None,
guild_ids=getattr(cls, '__discord_app_commands_default_guilds__', None),
guild_only=getattr(cls, '__discord_app_commands_guild_only__', False),
default_permissions=getattr(cls, '__discord_app_commands_default_permissions__', None),
extras=cls.__cog_group_extras__,
)
else:
group = None
self.__cog_app_commands_group__ = group
# Update the Command instances dynamically as well
for command in self.__cog_commands__:
setattr(self, command.callback.__name__, command)
parent = command.parent
if parent is not None:
# Get the latest parent reference
parent = lookup[parent.qualified_name] # type: ignore
# Update our parent's reference to our self
parent.remove_command(command.name) # type: ignore
parent.add_command(command) # type: ignore
if hasattr(command, '__commands_is_hybrid__') and parent is None:
app_command: Optional[Union[app_commands.Group, app_commands.Command[Self, ..., Any]]] = getattr(
command, 'app_command', None
)
if app_command:
group_parent = self.__cog_app_commands_group__
app_command = app_command._copy_with(parent=group_parent, binding=self)
# The type checker does not see the app_command attribute even though it exists
command.app_command = app_command # type: ignore
if self.__cog_app_commands_group__:
children.append(app_command) # type: ignore # Somehow it thinks it can be None here
if Cog._get_overridden_method(self.cog_app_command_error) is not None:
error_handler = self.cog_app_command_error
else:
error_handler = None
self.__discord_app_commands_error_handler__ = error_handler
for command in cls.__cog_app_commands__:
copy = command._copy_with(parent=self.__cog_app_commands_group__, binding=self)
# Update set bindings
if copy._attr:
setattr(self, copy._attr, copy)
if isinstance(copy, app_commands.Group):
copy.__discord_app_commands_error_handler__ = error_handler
for command in copy._children.values():
if isinstance(command, app_commands.Group):
command.__discord_app_commands_error_handler__ = error_handler
children.append(copy)
self.__cog_app_commands__ = children
if self.__cog_app_commands_group__:
self.__cog_app_commands_group__.module = cls.__module__
mapping = {cmd.name: cmd for cmd in children}
if len(mapping) > 25:
raise TypeError('maximum number of application command children exceeded')
self.__cog_app_commands_group__._children = mapping # type: ignore # Variance issue
return self
def get_commands(self) -> List[Command[Self, ..., Any]]:
r"""Returns the commands that are defined inside this cog.
This does *not* include :class:`discord.app_commands.Command` or :class:`discord.app_commands.Group`
instances.
Returns
--------
List[:class:`.Command`]
A :class:`list` of :class:`.Command`\s that are
defined inside this cog, not including subcommands.
"""
return [c for c in self.__cog_commands__ if c.parent is None]
def get_app_commands(self) -> List[Union[app_commands.Command[Self, ..., Any], app_commands.Group]]:
r"""Returns the app commands that are defined inside this cog.
Returns
--------
List[Union[:class:`discord.app_commands.Command`, :class:`discord.app_commands.Group`]]
A :class:`list` of :class:`discord.app_commands.Command`\s and :class:`discord.app_commands.Group`\s that are
defined inside this cog, not including subcommands.
"""
return [c for c in self.__cog_app_commands__ if c.parent is None]
@property
def qualified_name(self) -> str:
""":class:`str`: Returns the cog's specified name, not the class name."""
return self.__cog_name__
@property
def description(self) -> str:
""":class:`str`: Returns the cog's description, typically the cleaned docstring."""
return self.__cog_description__
@description.setter
def description(self, description: str) -> None:
self.__cog_description__ = description
def walk_commands(self) -> Generator[Command[Self, ..., Any], None, None]:
"""An iterator that recursively walks through this cog's commands and subcommands.
Yields
------
Union[:class:`.Command`, :class:`.Group`]
A command or group from the cog.
"""
from .core import GroupMixin
for command in self.__cog_commands__:
if command.parent is None:
yield command
if isinstance(command, GroupMixin):
yield from command.walk_commands()
def walk_app_commands(self) -> Generator[Union[app_commands.Command[Self, ..., Any], app_commands.Group], None, None]:
"""An iterator that recursively walks through this cog's app commands and subcommands.
Yields
------
Union[:class:`discord.app_commands.Command`, :class:`discord.app_commands.Group`]
An app command or group from the cog.
"""
for command in self.__cog_app_commands__:
yield command
if isinstance(command, app_commands.Group):
yield from command.walk_commands()
@property
def app_command(self) -> Optional[app_commands.Group]:
"""Optional[:class:`discord.app_commands.Group`]: Returns the associated group with this cog.
This is only available if inheriting from :class:`GroupCog`.
"""
return self.__cog_app_commands_group__
def get_listeners(self) -> List[Tuple[str, Callable[..., Any]]]:
"""Returns a :class:`list` of (name, function) listener pairs that are defined in this cog.
Returns
--------
List[Tuple[:class:`str`, :ref:`coroutine <coroutine>`]]
The listeners defined in this cog.
"""
return [(name, getattr(self, method_name)) for name, method_name in self.__cog_listeners__]
@classmethod
def _get_overridden_method(cls, method: FuncT) -> Optional[FuncT]:
"""Return None if the method is not overridden. Otherwise returns the overridden method."""
return getattr(method.__func__, '__cog_special_method__', method)
@classmethod
def listener(cls, name: str = MISSING) -> Callable[[FuncT], FuncT]:
"""A decorator that marks a function as a listener.
This is the cog equivalent of :meth:`.Bot.listen`.
Parameters
------------
name: :class:`str`
The name of the event being listened to. If not provided, it
defaults to the function's name.
Raises
--------
TypeError
The function is not a coroutine function or a string was not passed as
the name.
"""
if name is not MISSING and not isinstance(name, str):
raise TypeError(f'Cog.listener expected str but received {name.__class__.__name__} instead.')
def decorator(func: FuncT) -> FuncT:
actual = func
if isinstance(actual, staticmethod):
actual = actual.__func__
if not inspect.iscoroutinefunction(actual):
raise TypeError('Listener function must be a coroutine function.')
actual.__cog_listener__ = True
to_assign = name or actual.__name__
try:
actual.__cog_listener_names__.append(to_assign)
except AttributeError:
actual.__cog_listener_names__ = [to_assign]
# we have to return `func` instead of `actual` because
# we need the type to be `staticmethod` for the metaclass
# to pick it up but the metaclass unfurls the function and
# thus the assignments need to be on the actual function
return func
return decorator
def has_error_handler(self) -> bool:
""":class:`bool`: Checks whether the cog has an error handler.
.. versionadded:: 1.7
"""
return not hasattr(self.cog_command_error.__func__, '__cog_special_method__')
def has_app_command_error_handler(self) -> bool:
""":class:`bool`: Checks whether the cog has an app error handler.
.. versionadded:: 2.1
"""
return not hasattr(self.cog_app_command_error.__func__, '__cog_special_method__')
@_cog_special_method
async def cog_load(self) -> None:
"""|maybecoro|
A special method that is called when the cog gets loaded.
Subclasses must replace this if they want special asynchronous loading behaviour.
Note that the ``__init__`` special method does not allow asynchronous code to run
inside it, thus this is helpful for setting up code that needs to be asynchronous.
.. versionadded:: 2.0
"""
pass
@_cog_special_method
async def cog_unload(self) -> None:
"""|maybecoro|
A special method that is called when the cog gets removed.
Subclasses must replace this if they want special unloading behaviour.
.. versionchanged:: 2.0
This method can now be a :term:`coroutine`.
"""
pass
@_cog_special_method
def bot_check_once(self, ctx: Context[BotT]) -> bool:
"""A special method that registers as a :meth:`.Bot.check_once`
check.
This function **can** be a coroutine and must take a sole parameter,
``ctx``, to represent the :class:`.Context`.
"""
return True
@_cog_special_method
def bot_check(self, ctx: Context[BotT]) -> bool:
"""A special method that registers as a :meth:`.Bot.check`
check.
This function **can** be a coroutine and must take a sole parameter,
``ctx``, to represent the :class:`.Context`.
"""
return True
@_cog_special_method
def cog_check(self, ctx: Context[BotT]) -> bool:
"""A special method that registers as a :func:`~discord.ext.commands.check`
for every command and subcommand in this cog.
This function **can** be a coroutine and must take a sole parameter,
``ctx``, to represent the :class:`.Context`.
"""
return True
@_cog_special_method
def interaction_check(self, interaction: discord.Interaction[ClientT], /) -> bool:
"""A special method that registers as a :func:`discord.app_commands.check`
for every app command and subcommand in this cog.
This function **can** be a coroutine and must take a sole parameter,
``interaction``, to represent the :class:`~discord.Interaction`.
.. versionadded:: 2.0
"""
return True
@_cog_special_method
async def cog_command_error(self, ctx: Context[BotT], error: Exception) -> None:
"""|coro|
A special method that is called whenever an error
is dispatched inside this cog.
This is similar to :func:`.on_command_error` except only applying
to the commands inside this cog.
This **must** be a coroutine.
Parameters
-----------
ctx: :class:`.Context`
The invocation context where the error happened.
error: :class:`CommandError`
The error that happened.
"""
pass
@_cog_special_method
async def cog_app_command_error(self, interaction: discord.Interaction, error: app_commands.AppCommandError) -> None:
"""|coro|
A special method that is called whenever an error within
an application command is dispatched inside this cog.
This is similar to :func:`discord.app_commands.CommandTree.on_error` except
only applying to the application commands inside this cog.
This **must** be a coroutine.
Parameters
-----------
interaction: :class:`~discord.Interaction`
The interaction that is being handled.
error: :exc:`~discord.app_commands.AppCommandError`
The exception that was raised.
"""
pass
@_cog_special_method
async def cog_before_invoke(self, ctx: Context[BotT]) -> None:
"""|coro|
A special method that acts as a cog local pre-invoke hook.
This is similar to :meth:`.Command.before_invoke`.
This **must** be a coroutine.
Parameters
-----------
ctx: :class:`.Context`
The invocation context.
"""
pass
@_cog_special_method
async def cog_after_invoke(self, ctx: Context[BotT]) -> None:
"""|coro|
A special method that acts as a cog local post-invoke hook.
This is similar to :meth:`.Command.after_invoke`.
This **must** be a coroutine.
Parameters
-----------
ctx: :class:`.Context`
The invocation context.
"""
pass
async def _inject(self, bot: BotBase, override: bool, guild: Optional[Snowflake], guilds: Sequence[Snowflake]) -> Self:
cls = self.__class__
# we'll call this first so that errors can propagate without
# having to worry about undoing anything
await maybe_coroutine(self.cog_load)
# realistically, the only thing that can cause loading errors
# is essentially just the command loading, which raises if there are
# duplicates. When this condition is met, we want to undo all what
# we've added so far for some form of atomic loading.
for index, command in enumerate(self.__cog_commands__):
command.cog = self
if command.parent is None:
try:
bot.add_command(command)
except Exception as e:
# undo our additions
for to_undo in self.__cog_commands__[:index]:
if to_undo.parent is None:
bot.remove_command(to_undo.name)
try:
await maybe_coroutine(self.cog_unload)
finally:
raise e
# check if we're overriding the default
if cls.bot_check is not Cog.bot_check:
bot.add_check(self.bot_check)
if cls.bot_check_once is not Cog.bot_check_once:
bot.add_check(self.bot_check_once, call_once=True)
# while Bot.add_listener can raise if it's not a coroutine,
# this precondition is already met by the listener decorator
# already, thus this should never raise.
# Outside of, memory errors and the like...
for name, method_name in self.__cog_listeners__:
bot.add_listener(getattr(self, method_name), name)
# Only do this if these are "top level" commands
if not self.__cog_app_commands_group__:
for command in self.__cog_app_commands__:
# This is already atomic
bot.tree.add_command(command, override=override, guild=guild, guilds=guilds)
return self
async def _eject(self, bot: BotBase, guild_ids: Optional[Iterable[int]]) -> None:
cls = self.__class__
try:
for command in self.__cog_commands__:
if command.parent is None:
bot.remove_command(command.name)
if not self.__cog_app_commands_group__:
for command in self.__cog_app_commands__:
guild_ids = guild_ids or command._guild_ids
if guild_ids is None:
bot.tree.remove_command(command.name)
else:
for guild_id in guild_ids:
bot.tree.remove_command(command.name, guild=discord.Object(id=guild_id))
for name, method_name in self.__cog_listeners__:
bot.remove_listener(getattr(self, method_name), name)
if cls.bot_check is not Cog.bot_check:
bot.remove_check(self.bot_check)
if cls.bot_check_once is not Cog.bot_check_once:
bot.remove_check(self.bot_check_once, call_once=True)
finally:
try:
await maybe_coroutine(self.cog_unload)
except Exception:
pass
class GroupCog(Cog):
"""Represents a cog that also doubles as a parent :class:`discord.app_commands.Group` for
the application commands defined within it.
This inherits from :class:`Cog` and the options in :class:`CogMeta` also apply to this.
See the :class:`Cog` documentation for methods.
Decorators such as :func:`~discord.app_commands.guild_only`, :func:`~discord.app_commands.guilds`,
and :func:`~discord.app_commands.default_permissions` will apply to the group if used on top of the
cog.
Hybrid commands will also be added to the Group, giving the ability to categorize slash commands into
groups, while keeping the prefix-style command as a root-level command.
For example:
.. code-block:: python3
from discord import app_commands
from discord.ext import commands
@app_commands.guild_only()
class MyCog(commands.GroupCog, group_name='my-cog'):
pass
.. versionadded:: 2.0
"""
__cog_is_app_commands_group__: ClassVar[bool] = True