Dojo：'Hitch' 延迟类型范围的正确方法

Question

我在通过以下 Dojo 小部件的异步结构传递范围时遇到困难：

function callDef(){
//This function has the scope I need
        var deferred = new Deferred();
//try to hitch 'this' to function2
    DojoBaseLang.hitch(this,deferred.resolve(function2(1)));
    deferred.then(DojoBaseLang.hitch(this, function(callback) {
        callback.then(
            function (desiredResult) {
                //How to hitch callDef initial scope to function3?
                function3(desiredResult);
            },
            function (err) {
                // Do something when the process errors out
                console.log(err);
           })
           }),
    function (err) {
        // Do something when the process errors out
        console.log(err);
    }
);
function function2(variable){
//callDef scope not passed by hitch :(
    var dataStucture;
    //deferredFunction is a function which returns type Deferred
     return deferredFunction(hierarchyTableQuery, function(dataSet){
         //some iterative maniupulations will be performed on dataStructure here
         dataStructure = dataSet;

     }).then(function (){
         return dataStructure;
     });
}

function function3(variable){
    //need a way to also have scope in this method
    //doing other stuff
}

如您所见，callDef 首先调用 function2，returns 延迟，完成执行，然后将 function2 的 dataStructure 对象的结果传递给 function3。就 Deferred/Async 行为而言，这一切都很好，问题是被调用的 dojo/_base/lang.hitch 函数没有像通常那样将作用域从一个函数传递到另一个函数，在本例中是从 callDef至 function2。我还想将相同的范围传递给 function3。我的 require 语句是正确的，我还有其他非异步 .hitch 调用在同一个 widget/file 中成功。

感谢您的帮助

Answer 1

您可能正在寻找

…
deferred.resolve(DojoBaseLang.hitch(this,function2));
deferred.then(DojoBaseLang.hitch(this, function(callback) {
    callback(1).then(
        DojoBaseLang.hitch(this,function3),
        function (err) {
… // rest of the code

Dojo：'Hitch' 延迟类型范围的正确方法

Dojo: Correct way to 'Hitch' scope of deferred types

javascript

dojo

scope

asynchronous