我可以保证在jQuery中返回已填充的对象吗? [英] Can I make a promise return a populated object in jQuery?

问题描述

我对整套Deferred/Promise原则并不陌生，但是在阅读了全部内容之后，我所能找到的是关于如何使用它们返回ajax数据而不是javascript对象的信息.那可能吗?目的是使以下代码起作用:

I am new to the whole set of Deferred/Promise principles, but after reading about it all I can find is about how to use them to return ajax data, not a javascript object. Is that possible? The goal is to make the following code work:

var Binary = function(data){
   this.data = data;
}

var File = function(url){
   this.data = null;
   this.url = url;
   this.getData = function(){ 
      // return either cached version at this.data or fetch it
   }
}

// the  goal is to make the following possible:
var url = "http://www.google.com/humans.txt";
var file = new File(url);
file.getData().done(function(binary){ //binary should be equals to `new Binary(data)`
    alert("we got binary data object with the data being: " + binary.data);
});

推荐答案

我认为类似的方法应该起作用:

I think something like this should work:

this.getData = function(){ 
   var deferred = $.Deferred();
   deferred.resolve(new Binary(this.data));
   return deferred.promise();
};

您将返回一个promise，而不是返回数据本身，在这种情况下，该promise已经被解析，因此done回调可以立即使用您解析它的数据进行调用.

Instead of returning the data itself, you return a promise, which in this case has already been resolved, so the done callback can get called immediately with the data you resolve it with.

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