Why is setInterval in an Angular service only firing one time?

Question

I need to fetch updates from a server every few minutes so I'm using setInterval inside my DeliveriesService. Here is the relevant part of my `deliveries.service.ts` ``` import { Injectable, OnInit } from '@angular/core'; import { Subject } from 'rxjs/Subject'; import { Http } from '@angular/http'; import { Delivery, Product } from './delivery'; @Injectable() export class DeliveriesService implements OnInit { private fetchUrl = 'https://my.url'; private getInt; public deliveries$ = new Subject>(); constructor(private http: Http) { } ngOnInit() { this.startUpdate(); } startUpdate(): void { console.log('starting delivery fetch'); this.getInt = setInterval(this.fetchDeliveries(), 5 * 60 * 1000); } stopUpdate(): void { clearInterval(this.getInt); } updateNow(): void { this.stopUpdate(); this.startUpdate(); } fetchDeliveries(): void { console.log('updating deliveries'); this.http.get(this.fetchUrl) .map(res => { // do stuff, process data, etc. }).subscribe(); } } ``` The fi…

Accepted Answer

You need to pass the function reference to be executed instead of passing the return value of the function and use `.bind()` to set context

```
setInterval(this.fetchDeliveries.bind(this), 5 * 60 * 1000);
```

OR

```
setInterval(()=> this.fetchDeliveries(), 5 * 60 * 1000);
```

If you need to pass additional parameter to `fetchDeliveries`

```
setInterval(this.fetchDeliveries.bind(this), 5 * 60 * 1000, param1, param2);

this.fetchDeliveries(param1, param2){..}
```

Why is setInterval in an Angular service only firing one time?

Solution

Problem

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