Skip to content

ziomecka/portfolio-js-publisher

Folders and files

NameName
Last commit message
Last commit date

Latest commit

52a64a9 · Sep 11, 2019

History

80 Commits
Sep 8, 2019
Sep 9, 2019
Sep 7, 2019
Sep 6, 2019
Sep 8, 2019
Sep 6, 2019
Sep 9, 2019
Sep 11, 2019
Sep 6, 2019
Sep 9, 2019
Sep 7, 2019
Sep 7, 2019

Repository files navigation

npm version


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

Dependencies

  • Package has no production dependencies

DevDependencies

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