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?

• David: @melpomene if you could write a code or function to me, it will be awesome or any solution to me how to convert?
• melpomene: That's not what SO is for. If you want someone to write code for you, hire a programmer.

Answer 1

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)

• David: it's look like what i want; but what is new create[type]?
• Nenad Vracar: Updated so now value types work before everything was string.
• Nenad Vracar: 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: If its false we need to hardcode false because new Boolean('false') = true

Answer 2

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);

Answer 3

 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;

• zedling: please note that this script uses a newer JS format, you might have to downgrade the syntax
• Jonas Wilms: @zedling fetched from Redis -> nodejs -> ES7
• David: tnx, it will be run in node.js environment