Update Ajax url after retrywhen

Question

In retrywhen, i able to re-execute http request upon failure just like example at RxJs Observables: run retryWhen after some more async requests. I would like ajax(..) to re-input new option once it fails. Let say I would like to change header or url after first time http request fail. Any example?

Answer 1

All what retryWhen does is that it re-subscribes to its source Observable. What this means is up to you.

For example you can use Observable.defer() to return a different Observable on every re-subscription:

let retries = 0;

Observable.defer(() => {
    if (retries++ === 3) {
      return Observable.of('whatever');
    }
    return this.http.get(...);
  })
  .retryWhen((errors: Observable) => errors)
  .subscribe(...);

Similarly you could use for example Observable.create().