doOnCancel method Null safety

Stream<T> doOnCancel(FutureOr<void> onCancel())

Invokes the given callback function when the stream subscription is cancelled. Often called doOnUnsubscribe or doOnDispose in other implementations.

Example

final subscription = TimerStream(1, Duration(minutes: 1))
  .doOnCancel(() => print('hi'))
  .listen(null);

subscription.cancel(); // prints 'hi'

Implementation

Stream<T> doOnCancel(FutureOr<void> Function() onCancel) =>
    DoStreamTransformer<T>(onCancel: onCancel).bind(this);