onErrorOrNull method

Future<void> onErrorOrNull(
  1. void onError(
    1. dynamic error
    )
)

Executes the provided onError function if the future completes with an error.

onError is the function to be executed when the future completes with an error.

Example usage:

Future<int?>? nullableFuture = Future.error('An error occurred');
var result = await nullableFuture.onError((error) => print(error));
print(result); // prints: 'An error occurred'

Implementation

Future<void> onErrorOrNull(void Function(dynamic error) onError) {
  if (this == null) {
    return Future.value();
  }
  return this!.catchError((error) {
    onError(error);
    return null;
  });
}