onStart method

@override Future<bool> onStart()

Callback when this executor is started. Returns true if successfully started, false otherwise.

Implementation

@override
Future<bool> onStart() async {
  debug(
      '$runtimeType - ${taskControl.taskName} hasBeenScheduledUntil: ${taskControl.hasBeenScheduledUntil}');
  final from = taskControl.hasBeenScheduledUntil ?? DateTime.now();
  final to = DateTime.now().add(const Duration(days: 15)); // 15 days ahead
  // get all the instances where the task should be scheduled in the given range
  final schedule = triggerExecutor.getSchedule(from, to);

  if (schedule.isEmpty) {
    // Stop since the schedule is empty and there is not more to schedule.
    stop();
  } else {
    info(
        '$runtimeType Buffering ${schedule.length} app tasks ($schedule) for task ${taskExecutor.task.name}');

    Iterator<DateTime> it = schedule.iterator;
    DateTime current = DateTime.now();
    while (it.moveNext()) {
      current = it.current;
      AppTaskController().buffer(
        taskExecutor,
        taskControl,
        triggerTime: current,
      );
    }

    // Now stop since the schedule has all been enqueued.
    stop();

    // .. but start again when the scheduled time has passed.
    // This in the case where the app keeps running in the background
    var duration = current.millisecondsSinceEpoch -
        DateTime.now().millisecondsSinceEpoch;

    Timer(Duration(milliseconds: duration), () => start());
  }

  return true;
}