RxJS Samples

observable-interval.js

import * as Rx from 'rxjs';
import { setInterval } from 'timers';

const mockInterval = Rx.Observable.create(obs => {
  let i = 0;
  setInterval(function() {
    i = i + 1;
    obs.next(i);
  }, 500);
});

const result = mockInterval
  .do(o => o) //?
  .mergeMap(x =>
    x === 13 ?
      Rx.Observable.throw('Thirteens are bad') :
      Rx.Observable.of('a', 'b', 'c')
  )
  .catch(() => {
    console.log('error caught');
    return Rx.Observable.of('catch & toss');
  })
  ;

result.subscribe(
  x => console.log(x),
  e => console.error(e)
); //?

rxjs-delayed-interceptor.js

import * as Rx from 'rxjs';

const delayedWithPromise = value => {
  return new Promise(
    resolve => setTimeout(() => { resolve(value); }, 5000)
  );
};

const delayedWithObservable = value => {
  return new Rx.Observable(observer => {
    setTimeout(() => { observer.next(value); }, 5000);
  });
};

const logMessage = (msg, value = null) => {
  const now = new Date(Date.now());
  const time = `${now.getHours()}:${now.getSeconds()}`;
  const fullMsg = `${time} - ${msg} = ${value}}`;
  return console.log(fullMsg);
};

Rx.Observable.of('Delayed by Promise!')
  .do(value => logMessage('Starting delayed promise ...'))
  .concatMap(value => delayedWithObservable(value))
  .subscribe(value => logMessage('Delayed Promise', value));

Rx.Observable.of('Delayed by Observable!')
  .do(value => logMessage('Starting delayed observable ...'))
  .concatMap(value => delayedWithObservable(value))
  .subscribe(value => logMessage('Delayed Observable', value));

simple-subject.js

import * as Rx from 'rxjs';

const subject = new Rx.Subject();

subject.subscribe(r => {
  console.log(r);
});

subject.next('hello');
subject.next('goodbye');
subject.complete()
subject.next('me again');