nonebot2/nonebot/handler.py
2021-11-21 15:46:48 +08:00

123 lines
4.5 KiB
Python

"""
事件处理函数
============
该模块实现事件处理函数的封装,以实现动态参数等功能。
"""
import asyncio
from contextlib import AsyncExitStack
from typing import Any, Dict, List, Type, Callable, Optional
from nonebot.utils import get_name, run_sync
from nonebot.dependencies import (Param, Dependent, DependsWrapper,
get_dependent, solve_dependencies,
get_parameterless_sub_dependant)
class Handler:
"""事件处理器类。支持依赖注入。"""
def __init__(self,
func: Callable[..., Any],
*,
name: Optional[str] = None,
dependencies: Optional[List[DependsWrapper]] = None,
allow_types: Optional[List[Type[Param]]] = None,
dependency_overrides_provider: Optional[Any] = None):
"""
:说明:
装饰一个函数为事件处理器。
:参数:
* ``func: Callable[..., Any]``: 事件处理函数。
* ``name: Optional[str]``: 事件处理器名称。默认为函数名。
* ``dependencies: Optional[List[DependsWrapper]]``: 额外的非参数依赖注入。
* ``allow_types: Optional[List[Type[Param]]]``: 允许的参数类型。
* ``dependency_overrides_provider: Optional[Any]``: 依赖注入覆盖提供者。
"""
self.func = func
"""
:类型: ``Callable[..., Any]``
:说明: 事件处理函数
"""
self.name = get_name(func) if name is None else name
"""
:类型: ``str``
:说明: 事件处理函数名
"""
self.allow_types = allow_types or []
"""
:类型: ``List[Type[Param]]``
:说明: 事件处理器允许的参数类型
"""
self.dependencies = dependencies or []
"""
:类型: ``List[DependsWrapper]``
:说明: 事件处理器的额外依赖
"""
self.sub_dependents: Dict[Callable[..., Any], Dependent] = {}
if dependencies:
for depends in dependencies:
self.cache_dependent(depends)
self.dependency_overrides_provider = dependency_overrides_provider
self.dependent = get_dependent(func=func, allow_types=self.allow_types)
def __repr__(self) -> str:
return (
f"<Handler {self.name}({', '.join(map(str, self.dependent.params))})>"
)
def __str__(self) -> str:
return repr(self)
async def __call__(self,
*,
_stack: Optional[AsyncExitStack] = None,
_dependency_cache: Optional[Dict[Callable[..., Any],
Any]] = None,
**params) -> Any:
values, _ = await solve_dependencies(
_dependent=self.dependent,
_stack=_stack,
_sub_dependents=[
self.sub_dependents[dependency.dependency] # type: ignore
for dependency in self.dependencies
],
_dependency_overrides_provider=self.dependency_overrides_provider,
_dependency_cache=_dependency_cache,
**params)
if asyncio.iscoroutinefunction(self.func):
return await self.func(**values)
else:
return await run_sync(self.func)(**values)
def cache_dependent(self, dependency: DependsWrapper):
if not dependency.dependency:
raise ValueError(f"{dependency} has no dependency")
if dependency.dependency in self.sub_dependents:
raise ValueError(f"{dependency} is already in dependencies")
sub_dependant = get_parameterless_sub_dependant(
depends=dependency, allow_types=self.allow_types)
self.sub_dependents[dependency.dependency] = sub_dependant
def prepend_dependency(self, dependency: DependsWrapper):
self.cache_dependent(dependency)
self.dependencies.insert(0, dependency)
def append_dependency(self, dependency: DependsWrapper):
self.cache_dependent(dependency)
self.dependencies.append(dependency)
def remove_dependency(self, dependency: DependsWrapper):
if not dependency.dependency:
raise ValueError(f"{dependency} has no dependency")
if dependency.dependency in self.sub_dependents:
del self.sub_dependents[dependency.dependency]
if dependency in self.dependencies:
self.dependencies.remove(dependency)