retry

signature: retry(number: number): Observable

Retry an observable sequence a specific number of times should an error occur.

:bulb: Useful for retrying HTTP requests!

:bulb: If you only want to retry in certain cases, check out retryWhen!

:bulb: For non error cases check out repeat!

Examples

Example 1: Retry 2 times on error

( StackBlitz | jsBin | jsFiddle )

// RxJS v6+
import { interval, of, throwError } from 'rxjs';
import { mergeMap, retry } from 'rxjs/operators';

//emit value every 1s
const source = interval(1000);
const example = source.pipe(
  mergeMap(val => {
    //throw error for demonstration
    if (val > 5) {
      return throwError('Error!');
    }
    return of(val);
  }),
  //retry 2 times on error
  retry(2)
);
/*
  output:
  0..1..2..3..4..5..
  0..1..2..3..4..5..
  0..1..2..3..4..5..
  "Error!: Retried 2 times then quit!"
*/
const subscribe = example.subscribe({
  next: val => console.log(val),
  error: val => console.log(`${val}: Retried 2 times then quit!`)
});

Additional Resources

• retry

  :newspaper: - Official docs

• Error handling operator: retry and retryWhen

  :video_camera: :dollar: - André Staltz

:file_folder: Source Code: https://github.com/ReactiveX/rxjs/blob/master/src/internal/operators/retry.ts