anki/pylib/anki/hooks.py

92 lines
2.5 KiB
Python

# Copyright: Ankitects Pty Ltd and contributors
# License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
# pylint: disable=invalid-name
"""
Tools for extending Anki.
A hook takes a function that does not return a value.
A filter takes a function that returns its first argument, optionally
modifying it.
"""
from __future__ import annotations
import decorator
# You can find the definitions in ../tools/genhooks.py
from anki.hooks_gen import *
# Legacy hook handling
##############################################################################
_hooks: dict[str, list[Callable[..., Any]]] = {}
def runHook(hook: str, *args: Any) -> None:
"Run all functions on hook."
hookFuncs = _hooks.get(hook, None)
if hookFuncs:
for func in hookFuncs:
try:
func(*args)
except:
hookFuncs.remove(func)
raise
def runFilter(hook: str, arg: Any, *args: Any) -> Any:
hookFuncs = _hooks.get(hook, None)
if hookFuncs:
for func in hookFuncs:
try:
arg = func(arg, *args)
except:
hookFuncs.remove(func)
raise
return arg
def addHook(hook: str, func: Callable) -> None:
"Add a function to hook. Ignore if already on hook."
if not _hooks.get(hook, None):
_hooks[hook] = []
if func not in _hooks[hook]:
_hooks[hook].append(func)
def remHook(hook: Any, func: Any) -> None:
"Remove a function if is on hook."
hook = _hooks.get(hook, [])
if func in hook:
hook.remove(func)
# Monkey patching
##############################################################################
# Please only use this for prototyping or for when hooks are not practical,
# as add-ons that use monkey patching are more likely to break when Anki is
# updated.
#
# If you call wrap() with pos='around', the original function will not be called
# automatically but can be called with _old().
def wrap(old: Any, new: Any, pos: str = "after") -> Callable:
"Override an existing function."
def repl(*args: Any, **kwargs: Any) -> Any:
if pos == "after":
old(*args, **kwargs)
return new(*args, **kwargs)
elif pos == "before":
new(*args, **kwargs)
return old(*args, **kwargs)
else:
return new(_old=old, *args, **kwargs)
def decorator_wrapper(f: Any, *args: Any, **kwargs: Any) -> Any:
return repl(*args, **kwargs)
return decorator.decorator(decorator_wrapper)(old)