CancelableOperation then()

in lib/src/cancelable_operation.dart [149:177]

28 lines of code
8 McCabe index (conditional complexity)


  CancelableOperation<R> then<R>(FutureOr<R> Function(T) onValue,
      {FutureOr<R> Function(Object, StackTrace)? onError,
      FutureOr<R> Function()? onCancel,
      bool propagateCancel = false}) {
    final completer =
        CancelableCompleter<R>(onCancel: propagateCancel ? cancel : null);

    valueOrCancellation().then((T? result) {
      if (!completer.isCanceled) {
        if (isCompleted && !isCanceled) {
          assert(result is T);
          completer.complete(Future.sync(() => onValue(result as T)));
        } else if (onCancel != null) {
          completer.complete(Future.sync(onCancel));
        } else {
          completer._cancel();
        }
      }
    }, onError: (Object error, StackTrace stackTrace) {
      if (!completer.isCanceled) {
        if (onError != null) {
          completer.complete(Future.sync(() => onError(error, stackTrace)));
        } else {
          completer.completeError(error, stackTrace);
        }
      }
    });
    return completer.operation;
  }