@homie-rocks/bus
v0.1.0
Published
A small synchronous event bus for games: one handler set (Bus) or one set per event type (KeyedBus). The game supplies the event types; a handler that throws never stops the others.
Readme
@homie-rocks/bus
A small synchronous event bus for games, in two dispatch shapes. Bus<E> keeps
one handler set and hands every event to every subscriber; KeyedBus<M> keeps
one set per event type, so an event with no listeners costs one Map lookup.
Neither knows an event name: the game declares its own union or map and passes
it as the type parameter. A handler that throws is logged and the others still
run. There is no queue, no async delivery and no priority.
Part of Homie's open game engine: the packages the Homie games are built on.
Install
npm install --save-exact @homie-rocks/[email protected]Use
import { Bus } from '@homie-rocks/bus/Bus.js';
import { KeyedBus } from '@homie-rocks/bus/KeyedBus.js';
type GameEvent = { type: 'lap'; n: number } | { type: 'crash'; speed: number };
const bus = new Bus<GameEvent>();
const off = bus.on((e) => { if (e.type === 'lap') console.log('lap', e.n); });
bus.emit({ type: 'lap', n: 2 });
off();
type Events = { step: { dt: number }; reset: { seed: number } };
const keyed = new KeyedBus<Events>();
keyed.on('step', ({ dt }) => { /* runs 60 times a second */ });
keyed.once('reset', ({ seed }) => console.log('reset', seed));
keyed.emit('reset', { seed: 7 });There is no barrel file: import the module you need.
Modules
| module | what it does |
|---|---|
| Bus.js | Bus<E>: one handler set; on returns an Unsubscribe, emit dispatches in subscription order |
| KeyedBus.js | KeyedBus<M>: handlers per event type, with on, once, emit and clear |