Angular 2 Http, Observables and recursive requests

Question

I have a REST endpoint that returns a list of items, max 1000 items at a time. If there are more than 1000 items, the response has HTTP status 206 and there\'s a Nex

Answer 1

I got it working with minor tweaks to KwintenP's example:

// service.ts

getAllItems(): Observable {
  const getRange = (range?: string): Observable => {
    const headers: Headers = new Headers();
    if (range) {
      headers.set('Range', range);
    }

    return this.http.get('http://api/endpoint', { headers });
  };

  return getRange().expand((res: Response) => {
    if (res.status === 206) {
      const nextRange = res.headers.get('Next-Range');

      return getRange(nextRange);
    } else {
      return Observable.empty();
    }
  }).map((res: Response) => res.json());
}

In the component that subscribes to the Observable, I had to add a completed handler:

// component.ts

const temp = [];

service.getAllItems().subscribe(
  items => {
    // page received, push items to temp
    temp.push.apply(temp, items);
  },
  err => {
    // handle error
  },
  () => {
    // completed, expose temp to component
    this.items = temp;
  }
);