RxJS Operators

rxjs-operators.md

RxJS Operators

• catch - dealing with errors

delete(id) {
  return this.http.delete(this.url + '/' + id)
          .catch(this.handlerError)
}

• toPromise - use promise instead of observable(the observable is converted to a promise)

delete(id) {
  return this.http.delete(this.url + '/' + id)
          .toPromise()
          .catch(this.handlerError);
}

• retry - will retry the request {n} times

delete(id) {
  return this.http.delete(this.url + '/' + id)
          .retry(3)
          .catch(this.handlerError);
}

• switchMap - when dealing with multiple async operations

// switch from one observable to another
ordersService
  .getAll()
  .switchMap(orders => {
    this.orders = orders;
    return route.queryParamMap // here we're switching to this new observable that gets returned
  })
  .subscribe(params => {
    ....
  })