useSubscription

Subscribes to an observable and delegates emissions to the given callback or observer. Does not cause re-renders.

Useful for side effects: logging, analytics, syncing external state, etc.

Signature

function useSubscription<T>(
  observable: Observable<T>,
  observer: ((value: T) => void) | Partial<Observer<T>>,
): MutableRefObject<Subscription | null>;

Parameters

Parameter	Type	Description
observable	Observable<T>	The observable to subscribe to.
observer	((value: T) => void) | Partial<Observer<T>>	A callback for next, or an object with next, error, complete handlers.

Returns

MutableRefObject<Subscription | null> — a ref to the underlying RxJS Subscription for manual control if needed.

Example

Short form — only next:

useSubscription(clicks$, (value) => {
  console.log('clicked:', value);
});

Full observer:

useSubscription(data$, {
  next: (value) => console.log(value),
  error: (err) => console.error(err),
  complete: () => console.log('done'),
});

Live demo

Log (0 events):