是否可以重置jQuery延迟对象状态? [英] Is it possible to reset a jQuery deferred object state?

问题描述

是否可以将已解析的jQuery对象重置为未解析"状态，并重新开始其初始化和回调?

Is it possible to reset a resolved jQuery object to an 'unresolved' state and kick off it's initialization and callbacks all over again?

我正在做的特定事情是我在本地文件系统api上有一个jQuery延迟包装器.从那里我为我关心的事情建立了更高级别的递延:

The specific thing I'm doing is that I have a jQuery deferred wrapper over the local file system api. From there I build up higher level deferreds for the things I care about:

var getFs = defFs.requestQuota(PERSISTENT, 1024*1024)
              .pipe (bytes) -> defFs.requestFs(PERSISTENT, bytes)

var getCacheContents = getFs.pipe (fileSystem) -> 
      defFs.getDirectory('Cache', fileSystem.root).pipe (dir) ->
          defFs.readEntries(dir)

现在大多数时候，当我调用getCacheContents时，我不介意返回的备忘值，实际上，我更喜欢它.但是，当我想写入高速缓存时，我真的很希望能够重置该管道，并使其在下次访问时重新选择并重新扫描高速缓存.

Now most of the time, when I call getCacheContents I don't mind the memo-ized values being returned, in fact I prefer it. But, on the occasion when I want to write to the cache I really would like the ability to reset that pipe and have it re-select and rescan the cache next time its accessed.

我可以从$ .Callbacks中拼凑出一些东西，但是基于延迟的解决方案确实是理想的选择.

I could cobble something together from $.Callbacks but a deferred-based solution would really be ideal.

推荐答案

否. Promise由定义定义，它只能解析一次-从unresolved到或rejected.您将无法使用jQuery的Deferred s.

No. A Promise is by definition a thing that resolves only once - from unresolved to fulfilled OR to rejected. You will not be able to do this with jQuery's Deferreds.

您实际要搜索的是信号.他们将被解雇不止一次，但要提供类似的界面.周围有一些实现，您可以退出 js-signals 或

What you are actually searching for are Signals. They are to be fired more than once, but provide a similiar interface. There are some implementations around, you might ceck out js-signals or wire.js.

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