我怎么能叫在angularjs循环第二顺序的承诺设计模式的方法？ [英] How can I call the second sequential promise design pattern method in a loop in angularjs?

问题描述

新建angularjs和尝试的承诺模式的第一次 -

New to angularjs and trying out the promise pattern for the first time -

我有一个服务工具里面，我有这种方法 -

I have a service utility inside which I have this method -

this.getData= function(url){
        var defer = $q.defer();

        $http({method: 'GET', url: url}).
            success(function(data, status){
                defer.resolve(data);
            })
            .error(function(data, status) {
                defer.reject(status);
            });

        return defer.promise;
    };

现在我的控制器内，我打电话的方法称为A（）

Now inside my controller, I am calling a method called A()

   var A = function () {
    $scope.myobjectArray = [];


    return utility.getData("some url").then(funciton(data)
    {

        for (i = 0; i < data.length; i++) {
            $scope.myobjectArray.push(data[i].attribute1, new Array());

        }

    }
    ).
    then(function () {

        return getTheSecondAttributeArray();
    }).catch(function (status) {
//display error

    });


};

var getTheSecondAttributeArray = function () {

    for (i = 0; i < $scope.myObjectArray.length; i++) {
        var secondAttributeArray = [];
        var currentType = $scope.myObjectArray[i];
        utility.getData("some url").then(function (response) {
            for (j = 0; j < response.length; j++) {
//some response manipulation
                secondAttributeArray.push(response[j].text);
            }
        currentType.secondAttribute = secondAttributeArray;
        }).catch(function () {//catch error, display message
        })

    }
}

不过，它看起来像的$ scope.myobjectArray（第n-1元）的最后一个元素才刚刚填充。此外，这最后一个元素包含secondAttributeArray是所有secondAttributes为$ scope.myobjectArray的所有对象级联阵列。

However, it looks like that the last element of the $scope.myobjectArray (n-1th element) is only getting populated. Also, the secondAttributeArray that this last element contains is a concatenated array of all secondAttributes for all objects of the $scope.myobjectArray.

想不通我有什么可以改变这里。

Cannot figure out what can I change here.

编辑：

当我试图访问$ scope.myObjectArray [J]。'然后'函数里，故称$ scope.myObjectArray [J]是不确定的。 - >所以我创建了一个currentType可变的，并且$ scope.myObjectArray [J]。它和那是'，那么'函数内部很方便。奇怪！

When I tried accessing $scope.myObjectArray[j] inside the 'then' function, it said $scope.myObjectArray[j] was undefined. --> And so I created a currentType variable and assigned $scope.myObjectArray[j] to it and that was easily accessible inside the 'then' function. Weird!

另外，我看到只有$ scope.myObjectArray的最后一个对象获取价值，而不是休息。阵列中的其余对象是空

Also, I see that only the last object of the $scope.myObjectArray gets values and not the rest. The rest of the objects in the array are empty

任何帮助是AP preciated。

Any help is appreciated.

var myObject = function(firstattribute, secondAttribute){

this.firstattribute = firstattribute;
this.secondAttribute = secondAttribute;
}

由蜂巢（ Angularjs $ q.all ）这里的解释是，我面对的东西。我只得到了最后的循环中的数据。

The explanation here by Beehive (Angularjs $q.all) is something that I am facing. I only get the last loop's data.

推荐答案

这个问题是所有功能关闭。当获取数据返回时，你的currentType是最后一个，因为对于j循环已经结束。所以，你需要做的是移动code从 utility.getData 开始传递 currentType 和 seccondAttributeArray 这样的关闭将包含它们作为函数参数，而不是改变他们的对j循环的进展。

The issue is all in function closures. When the get data returns, your currentType is the last one because the for j loop ended already. So what you need to do is move the code starting from utility.getData to a separate method passing the parameters of the currentType and the seccondAttributeArray so the closure will contain them as parameters of the function and not change them as the for j loop progresses.

for (i = 0; i < $scope.myObjectArray.length; i++) { 
  var secondAttributeArray = []; 
  var currentType = $scope.myObjectArray[i];
  fillSecondAttributeArray($scope, secondAttributeArray, currentType);
 }

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