publisher-subscriber-pattern

About

• Javascript implementation of publisher subscriber pattern
• Can be used with different event emitters including browser window
• Provides Publisher class

API

Publisher

• Takes arguments: emitterInstance, addEventListener and removeEventListener
• Exposes methods: subscribe, unsubscribeAll and eventSubscribersCount
• Has property: subscribersCount

Arguments

emitterInstance

• Object that will be bound to addEventListener and removeEventListener as this (see Function.prototype.bind)

addEventListener and removeEventListener

• Methods exposed by emitterInstance which add and remove event listeners, respectively

Methods

subscribe

• Requires two arguments: eventName and eventCallback
• Accepts optional argument: subscriberInstance that will be bound to eventCallback as this
• Subscribes eventCallback to eventName, so whenever event occurs the eventCallback is called (with subscriberInstance as this, if provided)

unsubscribeAll

• Unsubscribes all eventCallbacks from all eventNames
• Runs removeEventListener of emitterInstance fro all eventNames

eventSubscriberCount

• Requires argument: eventName
• Returns number of eventCallbacks subscribed to the evenName

Properties

subscribersCount

• Returns number of eventCallbacks subscribed to all evenNames

Stack

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