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EventManager

import EventManager, { type EventMapBlank } from "@arclockproject/common/library/EventManager";

For examples and live demos, see the EventManager guide.

EventManager​

Class · default export

class EventManager<EventMap extends EventMapBlank>

A typed event emitter. EventMap maps each event name to its listener's signature, so dispatch and addListener are type-checked.

Constructor

new EventManager(defaults?: { [key in keyof EventMap]: EventMap[key][] })

Creates an event manager with no listeners, or with defaults.

Parameters

  • defaults? ({ [key in keyof EventMap]: EventMap[key][] }) — Listeners to start with, per event. The arrays are used as they are, not copied, so adding or removing listeners to said array also changes them in EventManager.

Example

const events = new EventManager<{
  pay: (client: string, amount: number) => void;
}>();

events.addListener("pay", (client, amount) => console.log(client, amount));
events.dispatch("pay", "Alex", 100); // logs "Alex 100"

EventManager.addListener()​

EventManager.addListener<k extends keyof EventMap>(type: k, listener: EventMap[k]): EventMap[k]

Adds a listener for type. Adding the same listener twice makes it run twice.

Parameters

  • type (k) — Event name.
  • listener (EventMap[k]) — Function to call when the event is dispatched.

Returns EventMap[k] — listener, so an inline function can be kept for removeListener.

EventManager.removeListener()​

EventManager.removeListener<k extends keyof EventMap>(type: k, listener: EventMap[k]): void

Removes one registration of listener for type. Does nothing if it was not added.

Parameters

  • type (k) — Event name.
  • listener (EventMap[k]) — The same function that was passed to addListener.

EventManager.removeAllListeners()​

EventManager.removeAllListeners<k extends keyof EventMap>(type: k): void

Removes every listener for type.

Parameters

  • type (k) — Event name.

EventManager.removeAll()​

EventManager.removeAll(): void

Removes every listener for every event.

EventManager.dispatch()​

EventManager.dispatch<k extends keyof EventMap>(type: k, ...payload: Parameters<EventMap[k]>): void

Calls every listener for type right away, in the order they were added.

Parameters

  • type (k) — Event name.
  • ...payload (Parameters<EventMap[k]>) — Arguments passed to each listener.

EventMapBlank​

Type

type EventMapBlank

The shape every event map must have: event names mapped to listener functions.

Properties

  • [key: string] ((...any: any) => void)