Ionic RC - Great Angular 2 pipe 'timeAgo'

Question

There is a great pipe posted on here.

I'm trying to make it work with Ionic 2 RC version and getting these three errors:

1. Type 'any' is not a constructor function type
2. Cannot find name 'ChangeDetectorRef'. Parameter 'ref' of constructor from exported class has or is using private name 'ChangeDetectorRef'.

3. Property 'interval' does not exist on type 'typeof Observable'

   import {Pipe, ChangeDetectorRef} from 'angular2/core';
   import {Observable} from 'rxjs/Observable';
   import {AsyncPipe} from 'angular2/common';
   
   
   @Pipe({
       name: 'messageTime',
       pure: false
   })
   export class MessageTimePipe extends AsyncPipe {  //Type 'any' is not a constructor function type
       value:Date;
       timer:Observable<string>;
   
   constructor(ref:ChangeDetectorRef) {  //Cannot find name 'ChangeDetectorRef'. Parameter 'ref' of constructor from exported class has or is using private name 'ChangeDetectorRef'.
       super(ref);
   }
   
   transform(obj:any, args?:any[]):any {
       if (obj instanceof Date) {
           this.value = obj;
   
           if(!this.timer) {
                   this.timer = this.getObservable();
           }
   
           return super.transform(this.timer, args);
       }
   
       return super.transform(obj, args);
   }
   
   private getObservable() {
       return Observable.interval(1000).startWith(0).map( () => {  //Property 'interval' does not exist on type 'typeof Observable'
           var result:string;
           // current time
           let now = new Date().getTime();
   
           // time since message was sent in seconds
           let delta = (now - this.value.getTime()) / 1000;
   
           // format string
           if (delta < 10) {
               result = 'jetzt';
           }
           else if (delta < 60) { 
               // sent in last minute
               result = 'vor ' + Math.floor(delta) + ' Sekunden';
           }
           else if (delta < 3600) { 
               // sent in last hour
               result = 'vor ' + Math.floor(delta / 60) + ' Minuten';
           }
           else if (delta < 86400) { 
               // sent on last day
               result = 'vor ' + Math.floor(delta / 3600) + ' Stunden';
           }
           else { 
               // sent more than one day ago
               result = 'vor ' + Math.floor(delta / 86400) + ' Tagen';
           }
           return result;
       });
   };
   

   }

Any idea on how to solve this?

Edit: I was able to take out error 3/ by using import {Observable} from 'rxjs/Rx';

Answer 1

Use angular 2 moment why do you needs to create something that already exists?

Answer 2

For rxjs 6.*

import { interval } from "rxjs";
const observable = interval(1000);