everAll function Null safety

Worker everAll(
  1. List<RxInterface> listeners,
  2. WorkerCallback callback,
  3. {dynamic condition = true,
  4. Function? onError,
  5. void onDone(
      )?,
    1. bool? cancelOnError}
    )

    Similar to ever, but takes a list of listeners, the condition for the callback is common to all listeners, and the callback is executed to each one of them. The Worker is common to all, so worker.dispose() will cancel all streams.

    Implementation

    Worker everAll(
      List<RxInterface> listeners,
      WorkerCallback callback, {
      dynamic condition = true,
      Function? onError,
      void Function()? onDone,
      bool? cancelOnError,
    }) {
      final evers = <StreamSubscription>[];
      for (var i in listeners) {
        final sub = i.listen(
          (event) {
            if (_conditional(condition)) callback(event);
          },
          onError: onError,
          onDone: onDone,
          cancelOnError: cancelOnError,
        );
        evers.add(sub);
      }
    
      Future<void> cancel() {
        for (var i in evers) {
          i.cancel();
        }
        return Future.value(() {});
      }
    
      return Worker(cancel, '[everAll]');
    }