Multicasting Operators

Share
ShareReplay

Publish Operator
PublishReplay Operator
PublishLast Operator

Share Operator

Share source among multiple subscribers

Publish Operator

Publish return an ConnectableObservable


        interface ConnectableObservable< T > extends Observable< T > {
            connect() : Subscription
            refCount(): Observable< T >
        }

Like a share Operator not garbage collected & emits data after a call to connect()

-The connect() method returns a Subscription instance that represents the shared underlying subscription. Unsubscribing from it will result in both subscribers no longer receiving any events.

Here

-The refCount() method is named after the garbage collection concept known as ref counting, or reference counting. The point is that it returns an observable sequence that stays connected to the source as long as there’s a least one active subscription. Does this sound familiar? It should because the share() operator we discussed a moment ago is little more than an alias for publish().refCount()

A connectable observable encapsulates the multicasting infrastructure, but does not immediately subscribe to the source. It subscribes to the source when its connect method is called
refCount returns an observable that maintains a reference count of the subscriptions that have been made

publish.refCount !== share cause the latter return a new Subject unlike the first one basically share becomes retriable unlike publish.refCount thus when refCount reach 0 and then a new Subscription coming share will could retry wheras publish.refCount throw the complete of is current complete Subject

PublishReplay Operator

This operator uses several parameters to determine the characteristics of a buffer to maintain

Here

Like a publish Operator but emitted previous values from a certain Buffer side parameter for each Observer Subscription

ShareReplay Operator

Here

Like a share Operator but emitted previous values from a certain Buffer side parameter for each Observer Subscription

PublishLast Operator

Here

Like a Last Operator with Hot Observable Behaviour

Other Multicasting Operators

multicasting => Share source utilizing the provided Subject here
cache
publishBehaviour
multicast => Returns an Observable that emits the results of invoking a specified selector on items emitted by a ConnectableObservable that shares a single subscription to the underlying stream here