javascript - 按父 ids 对象 Ramda 分组数组

Question

需要 Ramda 社区的帮助...我有一个对象数组，我需要按“chapter_id”排序，排序后，只需删除“chapter_id”:

const stuff = [
  { id: 1, title: "hello world", chapter_id: "4321" },
  { id: 2, title: "new title", chapter_id: "21" },
  { id: 3, title: "...", chapter_id: "33" },
  { id: 4, title: "huh!?", chapter_id: "14" },
  { id: 5, title: "From Earth", chapter_id: "11" },
  { id: 6, title: "alien", chapter_id: "11" },
  { id: 7, title: "Saturn", chapter_id: "11" },
  { id: 8, title: "Mars:/", chapter_id: "21" },
  { id: 9, title: "damn", chapter_id: "3" },
  { id: 10, title: "test", chapter_id: "11" },
  { id: 11, title: "ramda heeeelp", chapter_id: "31" },
  { id: 12, title: "hello?", chapter_id: "21" }
]

---

结果我想得到这个对象:

{
  "3": [
    {
      "id": "9",
      "title": "damn"
    }
  ],
  "11": [
    {
      "id": "5",
      "title": "From Earth"
    },
    {
      "id": "6",
      "title": "alien"
    },
    {
      "id": "7",
      "title": "Saturn"
    },
    {
      "id": "10",
      "title": "test"
    }
  ],
  "14": [
    {
      "id": "4",
      "title": "huh!?"
    }
  ],
  "21": [
    {
      "id": "2",
      "title": "new title"
    },
    {
      "id": "8",
      "title": "Mars:/"
    },
    {
      "id": "12",
      "title": "hello?"
    }
  ],
  "31": [
    {
      "id": "11",
      "title": "ramda heeeelp"
    }
  ],
  "33": [
    {
      "id": "3",
      "title": "..."
    }
  ],
  "4321": [
    {
      "id": "1",
      "title": "hello world"
    }
  ]
}

我是如何挣扎的:

let object = {};

map(({ chapter_id }) => {
  const composed = compose(
    map(evolve({ id: toString })), //here id is converted to a string
    filter(c => c.chapter_id === chapter_id),
  );
  object[chapter_id] = composed(stuff)
}, stuff);

我的结果:

{
  "3": [
    {
      "id": "9",
      "title": "damn",
      "chapter_id": "3" //Dissoc this
    }
  ],
  "11": [
    {
      "id": "5",
      "title": "From Earth",
      "chapter_id": "11" //dissoc this
    },
    {
      "id": "6",
      "title": "alien",
      "chapter_id": "11"  //and this
    },
    {
      "id": "7",
      "title": "Saturn",
      "chapter_id": "11" //and this
    },
    {
      "id": "10",
      "title": "test",
      "chapter_id": "11" //and this
    }
  ],
  "14": [
    {
      "id": "4",
      "title": "huh!?",
      "chapter_id": "14" //and this
    }
  ],
  "21": [
    {
      "id": "2",
      "title": "new title",
      "chapter_id": "21" //and this
    },
    {
      "id": "8",
      "title": "Mars:/",
      "chapter_id": "21" //and this
    },
    {
      "id": "12",
      "title": "hello?",
      "chapter_id": "21" //and this
    }
  ],
  "31": [
    {
      "id": "11",
      "title": "ramda heeeelp",
      "chapter_id": "31" //and this!!!!!!
    }
  ],
  "33": [
    {
      "id": "3",
      "title": "...",
      "chapter_id": "33" //and this..
    }
  ],
  "4321": [
    {
      "id": "1",
      "title": "hello world",
      "chapter_id": "4321" //and this:(
    }
  ]
}

它有效，但我无法从每个对象中分离“chapter_id”，有人知道如何解决这个问题吗？ :Δ

Answer 1

使用 Ramda，您可以按 key 分组，然后映射组，并从所有对象中分离 key:

const { pipe, groupBy, prop, map, dissoc } = R;

const fn = key => pipe(
  groupBy(prop(key)), // group by the key
  map(map(dissoc(key))) // remove the key from all objects in all groups
);

const stuff = [{"id":1,"title":"hello world","chapter_id":"4321"},{"id":2,"title":"new title","chapter_id":"21"},{"id":3,"title":"...","chapter_id":"33"},{"id":4,"title":"huh!?","chapter_id":"14"},{"id":5,"title":"From Earth","chapter_id":"11"},{"id":6,"title":"alien","chapter_id":"11"},{"id":7,"title":"Saturn","chapter_id":"11"},{"id":8,"title":"Mars:/","chapter_id":"21"},{"id":9,"title":"damn","chapter_id":"3"},{"id":10,"title":"test","chapter_id":"11"},{"id":11,"title":"ramda heeeelp","chapter_id":"31"},{"id":12,"title":"hello?","chapter_id":"21"}];

const result = fn('chapter_id')(stuff);

console.log(result);

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