尝试在此 trello.get 代码中获得正确的 JavaScript 变量范围

Question

我一直在努力在这段代码中正确设置变量 'listName' 范围 ...

var loadedAtriskopps = function(opps) {
    var listName = 'empty';
    $.each(opps.cards, function(index, opp) {
        Trello.get(
            '/cards/' + opp.id + '/list?fields=name', {fields: "id, name"}, function(list, err) {
                var listName = list.name;
                console.log(listName); //this returns the correct value
            });
        console.log(listName); //this returns 'empty'
        var opp = $("<div class='row'><div class='col-xs-6'><p class='output'>" + opp.name + "</b><br>On List: " + listName + " </p></div>    </div>");
        $('#opps').append(opp)
    });
};

在 Trello.get 函数内部它 returns 正确，但在它外部则不然。经过数小时的研究，仍然无法解决问题。

更新：

根据建议，尝试了此代码：

 var loadedAtriskopps = function(opps) {
    var listName = 'empty';
    $.each(opps.cards, function(index, opp) {
        console.log(opp.name); // returns correct value
        Trello.get('/cards/' + opp.id + '/list?fields=name', {fields: "id, name"})
              .success(function(list) {
                listName = list.name;
                console.log(listName); // // returns correct value
                // next line errors "Uncaught TypeError: Cannot read property 'name' of undefined" but listName is correct
                var opp = $("<div class='row'><div class='col-xs-6'><p class='output'>" + opp.name + "</b><br>On List: " + listName + " </p></div>    </div>");
                $('#opps').append(opp);
              })
              .error(function(err) {
                console.log("An error: " + err);
              });
    });
};

似乎我在成功回调中丢失了 opp 对象的定义。

解决方案：

 var loadedAtriskopps = function(opps) {
    var listName = 'empty';
    $.each(opps.cards, function(index, opp) {
        Trello.get('/cards/' + opp.id + '/list?fields=name', {fields: "id, name"})
              .success(function(list) {
                listName = list.name;
                var card = $("<div class='row'><div class='col-xs-6'><p class='output'>" + opp.name + "</b><br>On List: " + listName + " </p></div>    </div>");
                $('#opps').append(card);
              })
              .error(function(err) {
                console.log("An error: " + err);
              });
    });
};

谢谢达伦和安迪！

Answer 1

我认为您需要将 post-ajax 操作移至成功回调中。这应该确保您在之后具有实际值 ，ajax 具有 listName 的值。

尝试在此 trello.get 代码中获得正确的 JavaScript 变量范围

Trying to get the JavaScript variable scope correct in this trello.get code

javascript

jquery

scope

trello