npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

publisher-subscriber-pattern

v2.0.4

Published

Publisher subscriber pattern that can be used with different event emitters including browser window

Downloads

8

Readme

About

  • Javascript implementation of publisher subscriber pattern
  • Can be used with various event emitters including browser's window object
  • Provides Publisher class

Installation

npm i publisher-subscriber-pattern

Example

The example uses the browser's window object as emitterInstance. Other valid emitter instances can be also used.

import { Publisher } from 'publisher-subscriber-pattern';

const publisher = new Publisher(window, 'addEventListener','removeEventListener');

Publisher's subscribe method returns function, which can be used later to unsubscribe from the publisher's event.

const unsubscribe = publisher.subscribe('scroll', (event) => {});

// ...foo code...

unsubscribe();

There is also a method unsubscribeAll for unsubscribing all subscribers from all emitter's events.

publisher.unsubscribeAll();

API

Publisher

  • Parameters: emitterInstance, addListenerMethodName, removeListenerMethodName
  • Methods: subscribe, unsubscribeAll, eventSubscribersCount, subscribersCount

Parameters

emitterInstance

  • Object, which exposes addListener and removeListener methods
  • Behind the scenes, the emitterInstance is bound to addListener and removeListener methods as this (see Function.prototype.bind)

addListenerMethodName, removeListenerMethodName

  • Names of methods (strings), which are exposed by emitterInstance and, which add and remove event listeners, respectively

Methods

subscribe

  • Required parameters: eventName, eventCallback

  • Optional parameter: subscriberInstance, which will be bound to the eventCallback argument as this (see Function.prototype.bind)

  • Method subscribes eventCallback to eventName, so whenever event occurs the eventCallback is called

  • Returns function for unsubscribing from the event

unsubscribeAll

  • Unsubscribes all publisher's eventCallbacks from all emitter's eventNames

eventSubscriberCount

  • Required parameter: eventName
  • Returns number of subscribers' eventCallbacks subscribed to publisher's eventName

subscribersCount

  • Returns number of subscriber's eventCallbacks subscribed to all publisher's eventNames

Dependencies

Production dependencies

  • Package has no production dependencies

Main development dependencies

  • Typescript
  • Jasmine, chai, sinon
  • Babel
  • Node (EventEmitter)