js-fast-emitter

Description

js-fast-emitter is a lightweight npm library written in TypeScript that provides event emitter functionality. It allows you to easily manage and trigger events in your JavaScript applications.

Installation

You can install js-fast-emitter using npm:

npm install js-fast-emitter

Usage

To use js-fast-emitter, import the Emitter class from the package:

import Emitter from "js-fast-emitter"

Next, initialize a new instance of Emitter:

const AppEmitter = new Emitter();

Methods

add(eventName: string, listener: Function, options?: { once?: boolean, delay?: number }): void

Adds a listener function for the specified event name.

• eventName (string): The name of the event to listen for.
• listener (Function): The listener function to be called when the event is emitted.
• options (object, optional): Additional options for the listener.
  • once (boolean, optional): If set to true, the listener will trigger once and then be automatically removed. Defaults to false.
  • delay (number, optional): The delay in milliseconds before the listener is triggered. Defaults to 0.

Returns: An object with a remove function that can be used to remove the added listener.

Example:

// Listener triggered only once
AppEmitter.add('myEvent', (data) => {
  console.log('Event emitted:', data);
}, { once: true });

// Listener triggered with a delay of 1000 milliseconds
AppEmitter.add('myEvent', (data) => {
  console.log('Delayed event emitted:', data);
}, { delay: 1000 });

// Assign the listener to a const to remove it
const listener = AppEmitter.add('myEvent', (data) => {
  console.log('Event emitted:', data);
});

// Removing the listener
listener.remove();

emit(eventName: string, params: any): void

Emit a listener function for the specified event name.

• eventName (string): The name of the event to listen for.
• params (any): The listener params when the event is emitted.

Example:

AppEmitter.emit('myEvent', { message: "Hello World!" });

getAllListeners(eventName?: string): Function[]

Returns an array of listener functions for the specified event name. If no event name is provided, it returns all listener functions for all events.

• eventName (string, optional): The name of the event to get the listeners for.

Example:

const listeners = AppEmitter.getAllListeners('myEvent');
console.log(listeners); // [Function]