Dojo:纠正'延迟'延迟类型范围的方法

时间:2016-10-12 18:50:58

标签: javascript asynchronous scope dojo

我在通过以下Dojo小部件的异步结构传递范围时遇到了困难:

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,返回延迟,完成执行,然后将结果从function2的dataStructure对象传递到function3。这一切在延迟/异步行为方面都很好,问题是被调用的dojo/_base/lang.hitch函数没有像往常那样将范围从函数传递给函数,在这种情况下从callDef到{ {1}}。我还希望将相同的范围传递给function2。我的require语句是正确的,我有其他非同步function3调用,它们在同一个小部件/文件中成功。

感谢您的帮助

1 个答案:

答案 0 :(得分:2)

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