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作用域时遇到困难:

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
}

正如你所看到的，callDef首先调用function2，返回一个延迟的，完成执行，然后将function2的dataStructure对象的结果传递给function3。在延迟/异步行为方面，这一切都很好，问题是dojo/_base/lang.hitch函数被调用时没有像通常那样将作用域从函数传递到函数，在这种情况下从callDef到function2。我还想将相同的作用域传递给function3。我的require语句是正确的，并且我有其他非异步.hitch调用在相同的小部件/文件中是成功的。

感谢您的帮助

Answer 1

你可能正在寻找

…
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