@bivarcs/emitter NPM

Emitter

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A generic event emitter class.

Demo

https://bivarcs.github.io/emitter/demo/

const emitter = new Emitter({
  on: [
    ["myevent", (event) => console.log("event:", event)],
  ],
});

emitter.emit("myevent", {
  hoge: "fuga",
});

Installation

Package Manager

npm: npm i @bivarcs/emitter
yarn: yarn add @bivarcs/emitter

CDN

<script src="https://unpkg.com/@bivarcs/emitter/dist/js/emitter.min.js"></script>

Document

API Documentation (via: Typedoc)

Usage

const emitter = new Emitter({
  on: [
    // [type, listener, options?]
    ["test1", (event) => {
      console.log(event.type, event);
    }],
    ["test2", (event) => {
      console.log(event.type, event);
    }, {
      once: false,  // One-time run.
      order: 1,  // Order in events of the same type.
    }],
  ],
});

extends

Please create the extended class as follows.

class Hoge extends Emitter {
  constructor(options) {
    super(options);
  }
}

new Hoge({
  on: [
    // ...
  ],
});

on(), off()

There are also on() and off() methods.

const listener = (event) => {
  console.log(event.type, event);
};

// (type, listener, options?)
emitter.on("test", listener, {
  once: false,
  order: 1,
});

// (type, listener)
emitter.off("test", listener);

emit()

Emit an event.
The second argument is interpreted as {data: value} if it is not an object.

emitter.emit("test1");
/*
The callback is received as the first argument.

{
  type: "test1",
  target: instance,
}
*/

emitter.emit("test2", {
  hoge: "some value1",
  fufa: "some value2",
});
/*
{
  type: "test2",
  target: instance,
  hoge: "some value1",
  fufa: "some value2",
}
*/

emitter.emit("test3", "some value");
/*
{
  type: "test3",
  target: instance,
  data: "some value",
}
*/