Install

npm install typed-emitters

Single-event emitter

Create emitter

import { createTypedEmitter } from "typed-emitters";

const emitter =
    createTypedEmitter<
        [string, number] // Multiple args are supported
    >();

// Share the public interface
export const event = this.emitter.source;

emitter.emit("Test string", 1); // Type checking

Listen to events

// The source object allows listening to events but not emitting them

// The type of args is [string, number]
event.addListener((...args) => {
    console.log(args);
});

Multi-event emitter

Create emitter

import { createTypedMultiEmitter } from "typed-emitters";

const emitter =
    createTypedMultiEmitter<{
        'type1': [number],
        'type2' [string, number]
    }>();

// Share the public interface
export const events = this.emitter.source;

emitter.emit("type1", 1); // Type checking
emitter.emit("type2", "Test string", 1); // Type checking

Listen to events

// The source object allows listening to events but not emitting them

// The type of value is number
events.addListener("type1", (value) => {
    console.log(value);
});

// The type of args is [string, number]
events.addListener("type2", (...args) => {
    console.log(args);
});

Unsubscribing

// Option 1
event.removeListener(yourListener);

// Option 2
const dispose = event.addListener((...args) => {
    console.log(args);
});
dispose();

Other

Check if an emitter has any listeners

emitter.checkForListeners();

emitter.checkForListeners("type1");

Removing all listeners

emitter.removeAllListeners();

emitter.removeAllListeners("type1");

Exported types

• TypedEventEmitter<Args>
• TypedEventSource<Args>
• TypedMultiEventEmitter<ArgsByEventName>
• TypedMultiEventSource<ArgsByEventName>