嵌套 JSON 对象：在 CSV 导出中删除对源级 JSON 的引用

Question

我正在构建一个将以下格式的 JSON 转换为 CSV 的应用程序：

[
{
    "_type":  "End",
    "_source": {
        "timestamp_milli": 1499696661704,
        "timestamp": "2017-07-10T14:24:21.704Z",
        "country": "United States",
        "country-code": "US"
    }
},
{
    "_type": "Info",
    "_source": {
        "timestamp_milli": 1499696614807,
        "timestamp": "2017-07-10T14:23:34.807Z",
        "country": "United States",
        "country-code": "US"
    }
},
{
    "_type": "Menu",
    "_source": {
        "timestamp_milli": 1499696578167,
        "timestamp": "2017-07-10T14:22:58.167Z",
        "country": "United States",
        "country-code": "US"
    }
}
]

现在我正在使用 jsonexport npm 包，它为上述 JSON 文档生成一个 CSV 文件，格式如下：

_type,_source.timestamp_milli,_source.timestamp,_source.country,_source.country-code
End,1499696661704,2017-07-10T14:24:21.704Z,United States,US
Info,1499696614807,2017-07-10T14:23:34.807Z,United States,US
Menu,1499696578167,2017-07-10T14:22:58.167Z,United States,US

我一直在尝试删除“_source”。生成的 .csv 文件的标题中的文本。 JSON 文档将始终具有相同的结构，但“_source”中的元素会根据用户输入而改变。我正在尝试在不对 JSON 中的任何键进行硬编码的情况下完成此操作。

有人可以帮我找出使用 node.js 解决此问题的最佳方法吗？我有几个不同的想法是从 JSON 文档中删除“_source”级别，或者修剪“_source”。在将 csv 文件中的文本返回给浏览器之前。

Answer 1

[
    {
        "_type" : "End",
        "_source" : {
            "timestamp_milli" : 1499696661704,
            "timestamp" : "2017-07-10T14:24:21.704Z",
            "country" : "United States",
            "country-code" : "US"
        }
    },
    {
        "_type" : "Info",
        "_source" : {
            "timestamp_milli" : 1499696614807,
            "timestamp" : "2017-07-10T14:23:34.807Z",
            "country" : "United States",
            "country-code" : "US"
        }
    },
    {
        "_type" : "Menu",
        "_source" : {
            "timestamp_milli" : 1499696578167,
            "timestamp" : "2017-07-10T14:22:58.167Z",
            "country" : "United States",
            "country-code" : "US"
        }
    }
].map((item) => {
    // assign nested properties from _source
    Object.assign(item, item._source);
    // remove _source from item
    delete item._source;
});