如何在RxJS中使用node-walk

Question

Node walk呈现了一个带有这样几个事件的API。

walker.on('file', (root, filestats, next) => {
  // next should be called to goto next file
  next();
});
walker.on('end', () => {
  // the end of the stream
});

如果你从subscriber调用一个函数来通知source去流中的下一个项目，它是反应性的吗?事件不会等待订阅者对它作出反应，对吗?

如何将其转换为Rx Observable

Answer 1

最好是在它周围创建一个包装器:

Rx.Observable.fromWalk = function(root, options, scheduler) {
  scheduler = scheduler || Rx.Scheduler.currentThread;
  return Rx.Observable.create(function(observer) {
    var walker = walk.walk(root, options);
    function fileHandler(x) {
      observer.onNext({stats : x.stats, root : x.root});
      scheduler.scheduleWithState(x, function(s, i) {
        i.next();
      });
    }
    var files = Rx.Observable.fromEvent(walker, 'file', 
      function(arr) {
        return { root : arr[0], stats : arr[1], next : arr[2] };
    });
    var ended = Rx.Observable.fromEvent(walker, 'end');
    return new Rx.CompositeDisposable(
      files.subscribe(fileHandler),
      ended.subscribe(observer.onCompleted.bind(observer))
    );
  });
};

我相应地更新了你的例子

Answer 2

试试Rx.Observable.fromCallback:

var walkerOn = Rx.Observable.fromCallback(walker.on, walker)
var source = walkerOn('file');
var subscription = source.subscribe(observer);