如何获取延迟处理程序以将值返回给调用函数？ [英] How to get a deferred handler to return a value to the calling function?

问题描述

看下面的例子来了解我想要做的事情：

Look at the below example to understand what I am trying to do:

//Caller.js
callingFunction : function (...)
{
    var a = new Assistant();
    console.log("This object has been returned ", a.showDialog(...));
},

//Assistant.js
showDialog : function (...)
{
    deferred.then(lang.hitch(this, this._showDialog));
    //I want to return someObject to callingFunction
},

_showDialog : function (dialogData)
{
    ...
    ...
    return someObject;
},}

推荐答案

在该功能结束之前，没有什么可以返回的。相反，将回调传递给 showDialog ，并在延迟触发时将其调用回调。

Since it's deferred, there is nothing for it to return before that function ends. Instead, pass a callback into showDialog and have it call that callback when the deferred fires.

请在下面回覆你的评论：

Re your comment below:

你知道我将如何添加一个回调？

Do you know how I would add a callback to that?

自从我使用Dojo以来，它已经是几年了，所以它可能具有使这个更短的功能，但通常的方式将会如下所示：

It's been years since I used Dojo, so it may have features to make this shorter, but the usual way would look like this:

showDialog : function (callback)
{
    deferred.then(lang.hitch(this, function() {
        this._showDialog();
        callback(/*...whatever it is you want to pass back...*/);
    }));
},

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