How to rearrange a object with multiple levels based on groups and ascending order?

Question

I need to rearrange a chained object to a non-chained one. So, I need to create more objects to represent this.

basicaly I have this:

1. Person (code:1) (level 1)
 1.2 Person (code:2) (level 2)
  1.2.1 Person (code:3) (level 3)
 1.3 Person (code:4) (level 2)
  1.3.1 Person (code:5) (level 3)
  1.3.2 Person (code:6) (level 3)

And, expect this:

1. Person (code:1) (level 1)
2. Person (code:2) (level 2)
3. Person (code:3) (level 3)
4. Person (code:4) (level 2)
5. Person (code:5) (level 3)
6. Person (code:6) (level 3)

Now, in real world. My object:

[
    {
        "id": 5,
        "name": "Jhon",
        "code": "2",
        "employee_lvl2": [
            {
                "id": 23,
                "name": "Rodolf (John's employee 1)",
                "code": "9",
                "employee_lvl3": [
                    {
                        "id": 5,
                        "name": "Marcus (Rodolf's employee 1)",
                        "code": "18"
                    }
                ]
            },
            {
                "id": 17,
                "name": "Samuel (John's employee 2)",
                "code": "16",
                "employee_lvl3": [
                    {
                        "id": 11,
                        "name": "Jacob (Samuel's employee 1)",
                        "code": "21"
                    },
                    {
                        "id": 18,
                        "name": "Agnes (Samuel's employee 2)",
                        "code": "31"
                    }
                ]
            }
        ]
    },
    {
        "id": 4,
        "name": "Jennifer",
        "code": "1",
        "employee_lvl2": [
            {
                "id": 8,
                "name": "James (Jennifer's employee 1)",
                "code": "3",
                "employee_lvl3": [
                    {
                        "id": 12,
                        "name": "Jonathan (James's employee 1)",
                        "code": "8"
                    },
                    {
                        "id": 8,
                        "name": "Agnes (James's employee 2)",
                        "code": "3"
                    }
                ]
            },
            {
                "id": 7,
                "name": "Julie (Jennifer's employee 2)",
                "code": "6",
                "employee_lvl3": [
                    {
                        "id": 1,
                        "name": "Jacob (Julie's employee 1)",
                        "code": "1"
                    }
                ]
            }
        ]
    }
]

I expect something like: (ordered by code in all levels and stacking code in a property "stacked_code")

[
    {
        "id": 4,
        "name": "Jennifer",
        "code": "1"
    },
    {
        "id": 8,
        "name": "James (Jennifer's employee 1)",
        "code": "3",
        "stacked_code": "1.3"
    },
    {
        "id": 8,
        "name": "Agnes (James's employee 2)",
        "code": "3",
        "stacked_code": "1.3.3"
    },
    {
        "id": 12,
        "name": "Jonathan (James's employee 1)",
        "code": "8",
        "stacked_code": "1.3.8"
    },
    {
        "id": 7,
        "name": "Julie (Jennifer's employee 2)",
        "code": "6",
        "stacked_code": "1.6"
    },
    {
        "id": 1,
        "name": "Jacob (Julie's employee 1)",
        "code": "1",
        "stacked_code": "1.6.1"
    },
    {
        "id": 5,
        "name": "Jhon",
        "code": "2"
    },
    {
        "id": 23,
        "name": "Rodolf (John's employee 1)",
        "code": "9",
        "stacked_code": "2.9"
    },
    {
        "id": 5,
        "name": "Marcus (Rodolf's employee 1)",
        "code": "18",
        "stacked_code": "2.9.18"
    },
    {
        "id": 17,
        "name": "Samuel (John's employee 2)",
        "code": "16",
        "stacked_code": "2.16"
    },
    {
        "id": 11,
        "name": "Jacob (Samuel's employee 1)",
        "code": "21",
        "stacked_code": "2.16.21"
    },
    {
        "id": 18,
        "name": "Agnes (Samuel's employee 2)",
        "code": "31",
        "stacked_code": "2.16.31"
    }
]

I tried using some map() and push array but nothing significant. I know this somehow works with reduce but I can't help myself at the moment.

Answer 1

You can use a recursive function to solve this problem.

const outputArr = [];

/**
 * Convert a multilevel person object into one level
 * @param {Object} person The person object
 */
const convertToOneLevel = (person, parentCode = null) => {
  const newPerson = {
    id: person.id,
    name: person.name,
    code: person.code,
    stacked_code: parentCode ? `${parentCode}.${person.code}` : undefined,
  };
  outputArr.push(newPerson);
  const idx = Object.keys(person).findIndex((key) =>
    key.startsWith('employee_lvl')
  );
  if (idx !== -1) {
    person[Object.keys(person)[idx]].map((p) =>
      convertToOneLevel(
        p,
        newPerson.stacked_code ? newPerson.stacked_code : newPerson.code
      )
    );
  }
};

obj.forEach((p) => convertToOneLevel(p));

There obj is your input object.

Outpur array will be looked like-

[
  { id: 5, name: 'Jhon', code: '2', stacked_code: undefined },
  {
    id: 23,
    name: "Rodolf (John's employee 1)",
    code: '9',
    stacked_code: '2.9'
  },
  {
    id: 5,
    name: "Marcus (Rodolf's employee 1)",
    code: '18',
    stacked_code: '2.9.18'
  },
  {
    id: 17,
    name: "Samuel (John's employee 2)",
    code: '16',
    stacked_code: '2.16'
  },
  {
    id: 11,
    name: "Jacob (Samuel's employee 1)",
    code: '21',
    stacked_code: '2.16.21'
  },
  {
    id: 18,
    name: "Agnes (Samuel's employee 2)",
    code: '31',
    stacked_code: '2.16.31'
  },
  { id: 4, name: 'Jennifer', code: '1', stacked_code: undefined },
  {
    id: 8,
    name: "James (Jennifer's employee 1)",
    code: '3',
    stacked_code: '1.3'
  },
  {
    id: 12,
    name: "Jonathan (James's employee 1)",
    code: '8',
    stacked_code: '1.3.8'
  },
  {
    id: 8,
    name: "Agnes (James's employee 2)",
    code: '3',
    stacked_code: '1.3.3'
  },
  {
    id: 7,
    name: "Julie (Jennifer's employee 2)",
    code: '6',
    stacked_code: '1.6'
  },
  {
    id: 1,
    name: "Jacob (Julie's employee 1)",
    code: '1',
    stacked_code: '1.6.1'
  }
]