JS 通过深度嵌套的对象减少和分组 JSON答案

【问题标题】：JS Reduce and group JSON by deeply nested objectJS 通过深度嵌套的对象减少和分组 JSON
【发布时间】：2019-07-26 00:30:00
【问题描述】：

我正在通过 REST 提取一个 JSON，其中包含一个包含一些字段和一些嵌套对象的对象数组。

我要创建的是来自嵌套 JSON 对象数组的分组摘要对象，其结构如下：

 var data = [
        {
            "Id": 79,
            "Date": "2019-02-17T00:00:00-07:00",
            "StartTime": 1535385600,
            "EndTime": 1535416200,
            "Slots": [
                {
                    "blnEmptySlot": false,
                    "strType": "B",
                    "intStart": 3600,
                    "intEnd": 5400,
                    "intUnixStart": 1535389200,
                    "intUnixEnd": 1535391000,
                }
            ],
            "OperationalUnit": 3,
            "Created": "2019-01-31T11:23:29+02:00",
            "StartTimeLocalized": "2019-02-17T10:00:00+02:00",
            "EndTimeLocalized": "2019-02-17T19:00:00+02:00",
            "_MetaData": {
                "AttendeeInfo": {
                    "Id": 111,
                    "AttendeeDisplayName": "att_name1",
                    "AttendeeProfile": 406,
                    "Attendee": 406,
                    "Photo": "avatar_path"
                  },
                "OperationalUnitInfo": {
                    "Id": 3,
                    "OperationalUnitName": "op_unit_name",
                    "Company": 1,
                    "CompanyName": "comp_name",
                    "LabelWithCompany": "comp_label"
                },
            }
        },
        {
            "Id": 80,
            "Date": "2019-02-17T00:00:00-07:00",
            "StartTime": 1535385600,
            "EndTime": 1535416200,
            "Slots": [
                {
                    "blnEmptySlot": false,
                    "strType": "B",
                    "intStart": 3600,
                    "intEnd": 5400,
                    "intUnixStart": 1535389200,
                    "intUnixEnd": 1535391000,
                }
            ],
            "OperationalUnit": 3,
            "Created": "2019-01-31T11:23:29+02:00",
            "StartTimeLocalized": "2019-02-17T10:00:00+02:00",
            "EndTimeLocalized": "2019-02-17T19:00:00+02:00",
            "_MetaData": {
                "AttendeeInfo": {
                    "Id": 112,
                    "AttendeeDisplayName": "att_name2",
                    "AttendeeProfile": 407,
                    "Attendee": 407,
                    "Photo": "avatar_path"
                  },
                "OperationalUnitInfo": {
                    "Id": 3,
                    "OperationalUnitName": "op_unit_name",
                    "Company": 1,
                    "CompanyName": "comp_name",
                    "LabelWithCompany": "comp_label"
                },
            }
        }
    ];

总体目的是创建一个包含开始和结束日期时间的事件对象列表、一个 LabelWithCompany 字符串（深层嵌套对象）以及一个按 OperationalUnitName 以及开始和结束时间分组的所有参加者的列表。

例子：

[
    {
        "2019-02-17T00:00:00-08:00": {//Date
            "2019-02-17T10:00:00+02:00": {//StartTimeLocalized
                "2019-02-17T19:00:00+02:00": {//EndTimeLocalized
                    "[NYC] Network - Solutions": {//LabelWithCompany
                        "attendees": [
                            "att_name1",//AttendeeDisplayName
                            "att_name2"  //AttendeeDisplayName    
                        ]
                    }
                }
            }
        }
    }
]

我假设 map 和 reduce 是必要的功能，但我在执行多个嵌套 reduce 时遇到了麻烦。任何其他关于如何将这些对象聚合成包含每个会话的所有参与者的聚合格式的建议。

【问题讨论】：

你从哪里得到'att1'等等，从哪里来的？为什么你有一个数组作为结果集？
你不需要多个reduce，一个就够了。
stackoverflow.com/a/39235590/4928642
请添加反映给定数据的结果。
@NinaScholz 我已经编辑了输入和输出示例。我希望现在更清楚了。

标签： javascript json javascript-objects reducers

【解决方案1】：

您可以使用一些辅助函数来获取嵌套对象的值并设置路径并通过获取键数组来返回最后一个嵌套对象。

然后，您需要获取嵌套结果集的键，以获取推送到结果的值。

const
    getValue = (object, path) => [].concat(path).reduce((o, k) => o[k], object),
    setPath = (object, path) => [].concat(path).reduce((o, k) => o[k] = o[k] || {}, object);

var data = [{ Id: 79, Date: "2018-08-27T00:00:00-07:00", StartTime: 1535385600, EndTime: 1535416200, Slots: [{ blnEmptySlot: false, strType: "B", intStart: 3600, intEnd: 5400, intUnixStart: 1535389200, intUnixEnd: 1535391000 }], OperationalUnit: 3, Created: "2019-01-31T11:23:29+02:00", StartTimeLocalized: "2019-02-17T10:00:00+02:00", EndTimeLocalized: "2019-02-17T19:00:00+02:00", _MetaData: { AttendeeInfo: { Id: 111, AttendeeDisplayName: "att_name1", AttendeeProfile: 406, Attendee: 406, Photo: "avatar_path" }, OperationalUnitInfo: { Id: 3, OperationalUnitName: "op_unit_name", Company: 1, CompanyName: "comp_name", LabelWithCompany: "comp_label" } } }, { Id: 80, Date: "2018-08-27T00:00:00-07:00", StartTime: 1535385600, EndTime: 1535416200, Slots: [{ blnEmptySlot: false, strType: "B", intStart: 3600, intEnd: 5400, intUnixStart: 1535389200, intUnixEnd: 1535391000 }], OperationalUnit: 3, Created: "2019-01-31T11:23:29+02:00", StartTimeLocalized: "2019-02-17T10:00:00+02:00", EndTimeLocalized: "2019-02-17T19:00:00+02:00", _MetaData: { AttendeeInfo: { Id: 112, AttendeeDisplayName: "att_name2", AttendeeProfile: 407, Attendee: 407, Photo: "avatar_path" }, OperationalUnitInfo: { Id: 3, OperationalUnitName: "op_unit_name", Company: 1, CompanyName: "comp_name", LabelWithCompany: "comp_label" } } }],
    keys = ["Date", "StartTimeLocalized", "EndTimeLocalized", ["_MetaData", "OperationalUnitInfo", "LabelWithCompany"]],
    value = ["_MetaData", "AttendeeInfo", "AttendeeDisplayName"],
    result = data.reduce((r, o) => {
        var temp = setPath(r, keys.map(getValue.bind(null, o)));

        temp.attendees = temp.attendees || [];
        temp.attendees.push(getValue(o, value));
        return r;
    }, {});

console.log(result);

.as-console-wrapper { max-height: 100% !important; top: 0; }

【讨论】：

您对如何将其重新格式化为更容易从解析的数据创建谷歌日历事件有什么建议吗？
对不起，我不知道日历 api。
我只是想知道是否可以将 json 输出重新格式化为“移位”数组，这样可以更容易地遍历嵌套对象的层。例如：班次 = [ { 日期：“2019-02-17T00:00:00-08:00”，StartTimeLocalized ：“2019-02-17T10:00:00+02:00”，EndTimeLocalized ：“2019-02-17T19 :00:00+02:00", LabelWithCompany : "[NYC] 网络 - 解决方案", 与会者: [ "att_name1","att_name2" ] }, ANOTHER SHIFT OBJECT, ...]
这看起来像是一个不同的问题。但这是可能的。
我已经把它作为另一个问题发布了，谢谢尼娜！非常感谢您的帮助！

【解决方案2】：

您可以定义一个函数来简化层次结构的创建 (drill)，然后遍历记录，如下所示：

const data = [{"Id": 79,"Date": "2019-02-17T00:00:00-07:00","StartTime": 1535385600,"EndTime": 1535416200,"Slots": [{"blnEmptySlot": false,"strType": "B","intStart": 3600,"intEnd": 5400,"intUnixStart": 1535389200,"intUnixEnd": 1535391000,}],"OperationalUnit": 3,"Created": "2019-01-31T11:23:29+02:00","StartTimeLocalized": "2019-02-17T10:00:00+02:00","EndTimeLocalized": "2019-02-17T19:00:00+02:00","_MetaData": {"AttendeeInfo": {"Id": 111,"AttendeeDisplayName": "att_name1","AttendeeProfile": 406,"Attendee": 406,"Photo": "avatar_path"},"OperationalUnitInfo": {"Id": 3,"OperationalUnitName": "op_unit_name","Company": 1,"CompanyName": "comp_name","LabelWithCompany": "comp_label"},}},{"Id": 80,"Date": "2019-02-17T00:00:00-07:00","StartTime": 1535385600,"EndTime": 1535416200,"Slots": [{"blnEmptySlot": false,"strType": "B","intStart": 3600,"intEnd": 5400,"intUnixStart": 1535389200,"intUnixEnd": 1535391000,}],"OperationalUnit": 3,"Created": "2019-01-31T11:23:29+02:00","StartTimeLocalized": "2019-02-17T10:00:00+02:00","EndTimeLocalized": "2019-02-17T19:00:00+02:00","_MetaData": {"AttendeeInfo": {"Id": 112,"AttendeeDisplayName": "att_name2","AttendeeProfile": 407,"Attendee": 407,"Photo": "avatar_path"},"OperationalUnitInfo": {"Id": 3,"OperationalUnitName": "op_unit_name","Company": 1,"CompanyName": "comp_name","LabelWithCompany": "comp_label"},}}];

const drill = (o, key, ...keys) => key ? drill(o[key] = o[key] || {}, ...keys) : o; 

const result = {};    
for (const e of data) {
    const key = drill(result, e.Date, 
                              e.StartTimeLocalized, 
                              e.EndTimeLocalized, 
                              e._MetaData.OperationalUnitInfo.LabelWithCompany);
    key.attendees = (key.attendees || []).concat(
                              e._MetaData.AttendeeInfo.AttendeeDisplayName);
}

console.log(result);

注意：将输出包装在数组中似乎没有用，但您当然可以这样做。

【讨论】：