RX.JS Observer concept demo

rxjs.demo.js

import {Observable} from "rxjs";
import {Subject} from "rxjs";

// import {Observable} from "rxjs/Observable";
// import "rxjs/add/operator/map";
// import "rxjs/add/operator/filter";

let numbers = [1, 5, 10, 15];
let arrSource = Observable.from(numbers);

let contextCounter = 1;
let source = Observable.create(observer => {

    let index = 0;
    let contextId = contextCounter++;
    let produceValue = () => {
        console.log(`context [${contextId}] produce: ${numbers[index]}`);
        observer.next(numbers[index++]);
        if(index < numbers.length) {
            setTimeout(produceValue, 1000);
        }
        else {
            observer.complete();
        } 
    }

    produceValue();
});

let observer1 = {next: (x) => console.log(`observer1 got ${x}`)};
let observer2 = {next: (x) => console.log(`observer2 got ${x}`)};
let subj = new Subject();


console.log("subscribe sample");
source.subscribe(observer1);
source.subscribe(observer2);


/*
console.log("subj sample");

subj.subscribe(observer1);
subj.subscribe(observer2);
source.subscribe(subj);
*/

/*
console.log("multicasted sample");

let multicastedSource = source.multicast(subj);

multicastedSource.subscribe(observer1);
multicastedSource.connect();
multicastedSource.subscribe(observer2);
*/