remitter

remitter

A TypeScript friendly event emitter with easy re-emitting events.

Install

npm add remitter

Usage

import { Remitter } from "remitter";

interface EventConfig {
  event1: string;
  event2: void;
}

const remitter = new Remitter<EventConfig>();

const disposer = remitter.on("event1", value => {
  console.log("event1", value);
});

remitter.count("event1"); // 1

remitter.emit("event1", "hello"); // logs "event1 hello"

remitter.emit("event2"); // nothing logs

disposer();
remitter.emit("event1", "world"); // nothing logs

remitter.clear("event2"); // remove all listeners for event2
remitter.count(); // 0

remitter.destroy(); // removes all listeners and dispose tapped events

Tap

You may tap into other events which will be lazy-executed when listener count of an event name grows from 0 to 1 and be disposed when listener count drops from 1 to 0.

remitter.remit("event1", () => {
  const handler = e => {
    remitter.emit("event1", e.value + 1);
  };
  otherEvent.addListener(handler);
  return () => {
    otherEvent.removeListener(handler);
  };
});

The callback function can also be a pure function.

const tapToOtherEvent = remitter => {
  const handler = e => {
    remitter.emit("event1", e.value + 1);
  };
  otherEvent.addListener(handler);
  return () => {
    otherEvent.removeListener(handler);
  };
};

remitter.remit("event1", tapToOtherEvent);

Acknowledgment

Huge thanks to @recursivefunk for giving away the NPM package name remitter.