Higher-order observables

Higher-order Observables = observables of observables.

Operators to handle higher-order observables:

  • mergeMap (previously flatMap)
    • Creates new observable immediately.
    • Outer and inner observable emissions not guaranteed to be in same order.
  • concatMap
    • Waits for previous observable to complete and then creates new one.
    • Outer and inner observable emissions will be in same order.
  • switchMap
    • Unsubscribes from previous inner observable when new inner observable emission is received.
  • exhaustMap
    • Ignores any new inner observable emissions while the ongoing one is not complete.


Related: AngularAngular

Validators should be pure functions. #spaced
[[Change detection in Angular]]
Initial null problem in AsyncPipe - https://github.com/angular/angular/issues/43727.
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