Javascript 通过url和httpRequest解析云代码循环

我只想在我的“警报”对象中做一个简单的循环，其中包含一个url和一个单词。 对于每个警报，我都执行一个httpRequest来检查响应html代码中是否存在该单词。我是的，我把状态设置为真

我还想每次更新“updatedTo”列，即使在响应html代码中找不到该词，但我不知道为什么

我写了这个云代码，但它不起作用，或者它有时只在我只有单词present的项目时起作用

    Parse.Cloud.job("updateStatus", function(request, status) {
    Parse.Cloud.useMasterKey();
    var counter = 0;
    var AlertItem = Parse.Object.extend("Alert");
    var query = new Parse.Query(AlertItem);
    query.each(function(alert) {
            var alertTitle = alert.get("title");
            var alertUrl = alert.get("url");
            var alertStatus = alert.get("status");
            var alertWords = alert.get("research");
            console.log("Alert : " + alertTitle + " - Check if : " + alertWords + " is on : " + alertUrl)

            promise = promise.then(function() {
                    return Parse.Cloud.httpRequest({
                        url: alertUrl,
                        headers: {
                            'user-agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10) AppleWebKit/600.1.25 (KHTML, like Gecko) Version/8.0 Safari/600.1.25'
                        },
                    }).then(function(httpResponse) {
                            console.log("We succeded to access to the website");
                            var htmlCode = httpResponse.text;
                            if (htmlCode.indexOf(alertWords) >= 0) {
                                if (alertStatus == false) {
                                    alert.set("status", true);
                                    console.log("new status:true");
                                    return alert.save();
                                }
                            } else {
                                alert.set("status", false);
                                console.log("new status:false");
                                //I do this to updated the "updatedTo" field, but it doesn't work
                                return alert.save();
                            }
                            // You need to return a Promise here if non of the above condition meet.
                        },
                        function(error) {
                            console.error('Request failed with response code ' + httpResponse.headers.Location);
                            // You need to return a rejected promise here.
                        }
                    });
            });
        return promise;
    }).then(function() {
    status.success('Status updated');
    // Set the job's success status
}, function(error) {
    // Set the job's error status
    status.error("Uh oh, something went wrong.");
});
});

查询。每个（回调、选项）都来自文档

迭代查询的每个结果，为每个结果调用回调。如果回调返回一个承诺，则迭代将不会继续，直到该承诺得到满足。如果回调返回一个被拒绝的承诺，那么迭代将因该错误而停止。项目按未指定的顺序处理。查询不能有任何排序顺序，也不能使用“限制”或“跳过”

Parse.Cloud.job("updateStatus", function(request, status) {
    Parse.Cloud.useMasterKey();
    var counter = 0;
    var AlertItem = Parse.Object.extend("Alert");
    var query = new Parse.Query(AlertItem);
    query.each(function(alert) {
        var alertTitle = alert.get("title");
        var alertUrl = alert.get("url");
        var alertStatus = alert.get("status");
        var alertWords = alert.get("research");
        console.log("Alert : " + alertTitle + " - Check if : " + alertWords + " is on : " + alertUrl)


        return Parse.Cloud.httpRequest({
            url: alertUrl,
            headers: {
                'user-agent': 'A user classic agent'
            },
            success: function(httpResponse) {
                console.log("We succeded to access to the website");
                var htmlCode = httpResponse.text;
                if (htmlCode.indexOf(alertWords) >= 0) {
                    if (alertStatus == false) {
                        alert.set("status", true);
                        console.log("new status:true");
                        return alert.save();
                    }
                } else {
                    alert.set("status", false);
                    console.log("new status:false");
                    //I do this to updated the "updatedTo" field, but it doesn't work
                    return alert.save();
                }
                // You need to return a Promise here if non of the above condition meet.
            },
            error: function(httpResponse) {
                console.error('Request failed with response code ' + httpResponse.headers.Location);
                // You need to return a rejected promise here.
            }
        });
    }).then(function() {
        status.success('Status updated');
        // Set the job's success status
    }, function(error) {
        // Set the job's error status
        status.error("Uh oh, something went wrong.");
    });
});

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因此，在任何帮助下，这都很困难，但我最终找到了另一个接近我需要的职位，我对其进行了调整，我成功地使用了它，它在承诺方面非常有效：）：

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嗨，非常感谢你的回答！我承认我是javascript的初学者，我很难理解什么是承诺。我阅读了文档，似乎Promise避免了一次调用就能获得成功的方法，但我在这里没有使用任何Promise。我在这里有点迷路了…我编辑了我的代码，但我真的不明白我能用它做什么，提前谢谢你的解释…有什么帮助吗？谢谢：）！

var _ = require('underscore.js')

Parse.Cloud.job("updateStatus", function(request, response) {

var alerts = Parse.Object.extend("Alert");
var query = new Parse.Query(alerts);
query.equalTo("status", false);

query.find().then(function(alerts) {

    var promise = Parse.Promise.as();

    _.each(alerts, function(alert) {

        var alertUrl = alert.get("url");
        ...

        promise = promise.then(function() {
            return Parse.Cloud.httpRequest({
                url: alertUrl
                }).then(function(httpResponse) {
                    ...
                }, 
                function(error) {
                    ...
                });
            });
    });

    return promise;

}).then(function() {
    response.success("All status updated with success !");
}, 
function (error) {
    response.error("Error: " + error.code + " " + error.message);
});
});