Countdown Timer in Angular 6

Question

Hi I am trying to get an example of a countdown timer I found searching on Stack found here: Time CountDown in angular 2

This is my code:

import { Component, ElementRef, OnInit, OnDestroy } from '@angular/core';
import { Observable, Subscription, interval  } from 'rxjs';

@Component({
  selector: 'app-timer',
  templateUrl: './timer.component.html',
  styleUrls: ['./timer.component.css']
})
export class TimerComponent implements OnInit {
  private future: Date;
  private futureString: string;
  private diff: number;
  private $counter: Observable<number>;
  private subscription: Subscription;
  private message: string;

  constructor(elm: ElementRef) {
      this.futureString = elm.nativeElement.getAttribute('inputDate');
  }

  dhms(t) {
      let days, hours, minutes, seconds;
      days = Math.floor(t / 86400);
      t -= days * 86400;
      hours = Math.floor(t / 3600) % 24;
      t -= hours * 3600;
      minutes = Math.floor(t / 60) % 60;
      t -= minutes * 60;
      seconds = t % 60;

      return [
          days + 'd',
          hours + 'h',
          minutes + 'm',
          seconds + 's'
      ].join(' ');
  }

  ngOnInit() {
      this.future = new Date(this.futureString);
      this.$counter = Observable.interval(1000).map((x) => {
          this.diff = Math.floor((this.future.getTime() - new Date().getTime()) / 1000);
          return x;
      });

      this.subscription = this.$counter
          .subscribe((x) => this.message = this.dhms(this.diff));
  }
}

Getting the following error:

timer/timer.component.ts(44,34): error TS2339: Property 'interval' does not exist on type 'typeof Observable'.

I have tried every measure of importing I could find on Google but nothing has worked. I also updated to the latest version of rxjs and still nothing. Any help would be greatly appreciated.

I believe I may have some kind of versioning issue or something. Really stumped.

npm ERR! peer dep missing: [email protected] - 3, required by [email protected]
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npm ERR! missing: [email protected], required by [email protected]

Answer 1

Simply write:

import { interval } from 'rxjs';
import { map } from 'rxjs/operators'

interval(1000).pipe(
  map((x) => { /* your code here */ })
);

In RxJS 6+ there's no Observable.interval function.

Answer 2

From Rxjs 6.0 you have to import interval from rxjs/observable/interval.

And you have to use pipe operator to execute infinite number of operator sequentially.

import { interval } from 'rxjs';
import { map } from 'rxjs/operators'

this.$counter = interval(1000).pipe(
   map((x) => {
      this.diff = Math.floor((this.future.getTime() - new Date().getTime()) / 1000);
      return x;
  });
)

Reference: https://github.com/ReactiveX/rxjs/blob/master/doc/pipeable-operators.md#build-your-own-operators-easily