Files
seedPass/src/seedpass/core/pubsub.py
2025-07-18 17:02:05 -04:00

28 lines
1.0 KiB
Python

from collections import defaultdict
from typing import Callable, Dict, List, Any
class PubSub:
"""Simple in-process event bus using the observer pattern."""
def __init__(self) -> None:
self._subscribers: Dict[str, List[Callable[..., None]]] = defaultdict(list)
def subscribe(self, event: str, callback: Callable[..., None]) -> None:
"""Register ``callback`` to be invoked when ``event`` is published."""
self._subscribers[event].append(callback)
def unsubscribe(self, event: str, callback: Callable[..., None]) -> None:
"""Unregister ``callback`` from ``event`` notifications."""
if callback in self._subscribers.get(event, []):
self._subscribers[event].remove(callback)
def publish(self, event: str, *args: Any, **kwargs: Any) -> None:
"""Notify all subscribers of ``event`` passing ``*args`` and ``**kwargs``."""
for callback in list(self._subscribers.get(event, [])):
callback(*args, **kwargs)
# Global bus instance for convenience
bus = PubSub()