有没有办法在JavaScript中将大对象转换为较小的对象？

Let's say i get from the server the object A

假设我从服务器获取对象A.

    `A = {
  "kind": "books#volume",
  "id": "8Q1wW6Us-O0C",
  "etag": "k2MS/7WPcsY",
  "selfLink": "https://www.googleapis.com/books/v1/volumes/8Q1wW6Us-O0C",
  "volumeInfo": {
    "title": "Years with Frank Lloyd Wright",
    "subtitle": "Apprentice to Genius",
    "authors": [
      "Edgar Tafel"
    ],
    "publisher": "Courier Corporation",
    "publishedDate": "1979",
    "description": "This insightful memoir by a former apprentice presents a revealing portrait of the great American architect, providing illuminating anecdotes about Wright's Prairie home and Oak Park periods, and much more.",
    "industryIdentifiers": [
      {
        "type": "ISBN_10",
        "identifier": "0486248011"
      },
      {
        "type": "ISBN_13",
        "identifier": "9780486248011"
      }
    ],
    "readingModes": {
      "text": false,
      "image": true
    },
    "pageCount": 228,
    "printType": "BOOK",
    "categories": [
      "Architecture"
    ],
    "averageRating": 3.5,
    "ratingsCount": 2,
    "maturityRating": "NOT_MATURE",
    "allowAnonLogging": false,
    "contentVersion": "1.1.1.0.preview.1",
    "imageLinks": {
      "smallThumbnail": "http://books.google.ru/books/content?id=8Q1wW6Us-O0C&printsec=frontcover&img=1&zoom=5&edge=curl&source=gbs_api",
      "thumbnail": "http://books.google.ru/books/content?id=8Q1wW6Us-O0C&printsec=frontcover&img=1&zoom=1&edge=curl&source=gbs_api"
    },
    "previewLink": "http://books.google.ru/books?id=8Q1wW6Us-O0C&printsec=frontcover&hl=&source=gbs_api",
    "infoLink": "http://books.google.ru/books?id=8Q1wW6Us-O0C&hl=&source=gbs_api",
    "canonicalVolumeLink": "http://books.google.ru/books/about/Years_with_Frank_Lloyd_Wright.html?hl=&id=8Q1wW6Us-O0C"
  },
      }

Is there any fast way in JavaScript to create another object from this one based on selected properties?

在JavaScript中是否有任何基于所选属性的快速方法来创建另一个对象?

B = {"id": "8Q1wW6Us-O0C",
     "title": "Years with Frank Lloyd Wright",
     "publishedDate": "1979",
      "pageCount": 228,
      and some other properties}

Don't read this: I am asked to add some details, but I guess this is enough.

不读这个:我被要求添加一些细节,但我想这就足够了。

2 个解决方案

#1

I suggest to store the path of the wanted properties

我建议存储所需属性的路径

wanted = {
    id: 'id',
    title: 'volumeInfo.title',
    publishedDate: 'volumeInfo.publishedDate',
    pageCount: 'volumeInfo.pageCount'
}

and use it with Array#reduce for the value.

并使用Array#reduce作为值。

var data = { "kind": "books#volume", "id": "8Q1wW6Us-O0C", "etag": "k2MS/7WPcsY", "selfLink": "https://www.googleapis.com/books/v1/volumes/8Q1wW6Us-O0C", "volumeInfo": { "title": "Years with Frank Lloyd Wright", "subtitle": "Apprentice to Genius", "authors": ["Edgar Tafel"], "publisher": "Courier Corporation", "publishedDate": "1979", "description": "This insightful memoir by a former apprentice presents a revealing portrait of the great American architect, providing illuminating anecdotes about Wright's Prairie home and Oak Park periods, and much more.", "industryIdentifiers": [{ "type": "ISBN_10", "identifier": "0486248011" }, { "type": "ISBN_13", "identifier": "9780486248011" }], "readingModes": { "text": false, "image": true }, "pageCount": 228, "printType": "BOOK", "categories": ["Architecture"], "averageRating": 3.5, "ratingsCount": 2, "maturityRating": "NOT_MATURE", "allowAnonLogging": false, "contentVersion": "1.1.1.0.preview.1", "imageLinks": { "smallThumbnail": "http://books.google.ru/books/content?id=8Q1wW6Us-O0C&printsec=frontcover&img=1&zoom=5&edge=curl&source=gbs_api", "thumbnail": "http://books.google.ru/books/content?id=8Q1wW6Us-O0C&printsec=frontcover&img=1&zoom=1&edge=curl&source=gbs_api" }, "previewLink": "http://books.google.ru/books?id=8Q1wW6Us-O0C&printsec=frontcover&hl=&source=gbs_api", "infoLink": "http://books.google.ru/books?id=8Q1wW6Us-O0C&hl=&source=gbs_api", "canonicalVolumeLink": "http://books.google.ru/books/about/Years_with_Frank_Lloyd_Wright.html?hl=&id=8Q1wW6Us-O0C" } },
    wanted = { id: 'id', title: 'volumeInfo.title', publishedDate: 'volumeInfo.publishedDate', pageCount: 'volumeInfo.pageCount' },
    result = {};

Object.keys(wanted).forEach(function (k) {
    result[k] = wanted[k].split('.').reduce(function (r, a) {
        return r && r[a];
    }, data);
})

console.log(result);

#2

try this

var selectedProperties = ["id", "title", "publishedDate", "pageCount"];
var B = {};
selectedProperties.forEach( function(key){
   A[key] && (B[key] = A[key]);
});

#1