how to create object from specific another object

Question

i have this type of object which fetched from Redis

{
        'username': 'hamet',
        'username_Type': 'string',
        'meta': 'object',
        'meta_Type': 'object',
        'meta.avatar': '/avatar.png',
        'meta.avatar_Type': 'string',
        'meta.active': 'false',
        'meta.active_Type': 'boolean',
        'meta.someArr': 'array',
        'meta.someArr_Type': 'array',
        'meta.someArr.0': 'object',
        'meta.someArr.0_Type': 'object',
        'meta.someArr.0.field': '123',
        'meta.someArr.0.field_Type': 'number',
        'meta.someArr.1': 'object',
        'meta.someArr.1_Type': 'object',
        'meta.someArr.1.field': '321',
        'meta.someArr.1.field_Type': 'number'
}

all i want is convert this object to valid object like this:

{
        username: 'hamet',
        meta: {
            avatar: '/avatar.png',
            active: false,
            someArr: [
                { field: 123 },
                { field: 321 }
            ]

        }
}

once i created iterated function, but there was a problem with that. is it possible to convert with Iterated function and how?

@melpomene if you could write a code or function to me, it will be awesome or any solution to me how to convert? — David
– David, Commented Apr 3, 2018 at 11:48
That's not what SO is for. If you want someone to write code for you, hire a programmer. — melpomene
– melpomene, Commented Apr 3, 2018 at 11:48

Nenad Vracar · Accepted Answer · 2018-04-03 12:36:54Z

2

You could create object with value types that you will use for creating new instances of different data types and then use reduce() method to build your object.

const data = {"username":"hamet","username_Type":"string","meta":"object","meta_Type":"object","meta.avatar":"/avatar.png","meta.avatar_Type":"string","meta.active":"false","meta.active_Type":"boolean","meta.someArr":"array","meta.someArr_Type":"array","meta.someArr.0":"object","meta.someArr.0_Type":"object","meta.someArr.0.field":"123","meta.someArr.0.field_Type":"number","meta.someArr.1":"object","meta.someArr.1_Type":"object","meta.someArr.1.field":"321","meta.someArr.1.field_Type":"number"}

const result = {}
const create = {'string': String,'number': Number,'boolean': Boolean,'array': Array,'object': Object}
const findType = (key, obj) => obj[key]

Object.keys(data).forEach(key => {
  if (!key.includes('Type')) {
    key.split('.').reduce((r, e, i, arr) => {
      let type = findType(key + '_Type', data);
      let value = create[data[key]] || arr[i + 1] ? new create[type] : new create[type](data[key]).valueOf()
      if (data[key] == 'false') value = false
      r[e] = r[e] || value;
      return r[e]
    }, result)
  }
})

console.log(result)

edited Apr 3, 2018 at 12:36

answered Apr 3, 2018 at 12:22

Nenad Vracar

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4 Comments

David Over a year ago

it's look like what i want; but what is new create[type]?

Nenad Vracar Over a year ago

Updated so now value types work before everything was string.

Nenad Vracar Over a year ago

Well it will create new instance of data type you have in your object, so for array it will create new array, string => new String ...

Nenad Vracar Over a year ago

If its false we need to hardcode false because new Boolean('false') = true

Ori Drori · Accepted Answer · 2018-04-03 12:49:01Z

Get an array of keys with Object.keys(). Filter out the _Type keys. Sort the keys to ensure that parents (shorter) keys are first, since keys` order in an object is not ensured.

Reduce the array of keys, and for each key get it's value by type. If the type is not object/array use the actual key value. Iterate the result object with Array.forEach(), until you get to the leaf. Add the key with the value.

const obj = {"meta.someArr.1.field":"321","username":"hamet","username_Type":"string","meta":"object","meta_Type":"object","meta.avatar":"/avatar.png","meta.avatar_Type":"string","meta.active":"false","meta.active_Type":"boolean","meta.someArr":"array","meta.someArr_Type":"array","meta.someArr.0":"object","meta.someArr.0_Type":"object","meta.someArr.0.field":"123","meta.someArr.0.field_Type":"number","meta.someArr.1":"object","meta.someArr.1_Type":"object","meta.someArr.1.field_Type":"number"};

const byType = {
  object: Object,
  array: Array
};

const result = Object.keys(obj)
  .filter((k) => !k.includes('_Type')) // remove Type keys
  .sort((a, b) => a.length - b.length) // ensures that shorter (parent) keys are first
  .reduce((r, k) => {
    const type = obj[`${k}_Type`];

    const valueByType = byType[type] && byType[type]();
    const value = valueByType ? valueByType : obj[k];
    const keys = k.split('.');

    let current = r;

    keys.forEach((key, i) => {   
      if(!(key in current)) current[key] = value;
      else current = current[key];
    });

    return r;
}, {});

console.log(result);

Jonas Wilms · Accepted Answer · 2018-04-03 11:50:52Z

1

  const result = {};

  function apply(obj, value, key, ...keys) {
    if(keys.length) {
     apply(obj[key] || (obj[key] = {}), value ...keys);
    } else {
     obj[key] = value;
   }
 }

 for(const [key, value] of Object.entries(yourObj))
   apply(result, value, ...key.split("."));

You could use a recursive approach to generate the nested structure. I havent included a check if key is a number so that it creates an array, thats your job ;)

If you prefer functional programming:

  const apply = (obj, value, ...keys) => keys.slice(1).reduce((obj, key) => obj[key] || (obj[key] = {}), obj)[keys.pop()] = value;

edited Apr 3, 2018 at 11:50

answered Apr 3, 2018 at 11:47

Jonas Wilms

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3 Comments

zedling Over a year ago

please note that this script uses a newer JS format, you might have to downgrade the syntax

Jonas Wilms Over a year ago

@zedling fetched from Redis -> nodejs -> ES7

David Over a year ago

tnx, it will be run in node.js environment

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