What is the best way to transform object names to a desired format

user_11505456 0
Viewed 71

Whats the best way to map all object properties into a new object format with different property names example:

this is the desired format

const person = {
  firstName: 'john',
  lastName: 'doe',
  houses: [{ housName: 'Kruger' }]
}

and I have these two objects

const person1 = {
  prenom: 'john', //this should be mapped to the firstName
  nom: 'doe', //this should be mapped to the lastName
  houses: [{ house_name: 'Kruger' }]
}

const person2 = {
  name: 'john', // this should be mapped to the firstName
  familyName: 'doe', // this should be assigned to the lastName
  Houses: [{ House_Name: 'Kruger' }]
};

The goals is to make person1 and person2 with all their properties and sub properties look like person.

I HAVE TRIED

export class Person {
  @Expose({ name: 'prenom' })
  firstName: string;

  @Expose({ name: 'nom' })
  lastName: string;

  }
}

//this should give a formatted version from person1 ==> person
const formatted = plainToClass(person1,Person)

However this would require me to create multiple iterations of Person class which is not convenient if we would like to use this class for typing.

typescript node.js javascript
3 Answers

First you need to get all the object keys and values by Object.entries(obj), then on each key we need to turn it from pascal case to camel case first we need to turn the string to lower case then with replace /_([a-z])/gi which capture the first letter after the underscore _, and turn it Upper case.

str.toLowerCase().replace(/_([a-z])/gi, function (g) { return g[1].toUpperCase(); });

Then reduce the array and covert it back to an object.

const mapToCamelCase = (obj) => {
    return Object.entries(obj).reduce((acc, [key,value]) => {
        var keyCamelCased = toCamelCase(key)
       acc[keyCamelCased] = value
       return acc
    }, {})
}


const person1 = {
  first_name: 'john',
  last_name: 'doe',
  houses: [{ house_name: 'Kruger' }]
}
const person2 = {
  First_Name: 'john',
  Last_Name: 'doe',
  Houses: [{ House_Name: 'Kruger' }]
};


const toCamelCase = (str) => {
  return str.toLowerCase().replace(/_([a-z])/gi, function (g) { return g[1].toUpperCase(); });
}


const mapToCamelCase = (obj) => {
    return Object.entries(obj).reduce((acc, [key,value]) => {
        var keyCamelCased = toCamelCase(key)
       acc[keyCamelCased] = value
       return acc
    }, {})
}

console.log(mapToCamelCase(person1))
console.log(mapToCamelCase(person2))

user_118879020

A simple recursive function can do the name conversion you want. This will work for input with any depth of entries in it.

Using Object.entries() and Object.fromEntries()

const person1 = { first_name: "john", last_name: "doe", houses: [{ house_name: "Kruger" }], }; const person2 = { First_Name: "john", Last_Name: "doe", Houses: [{ House_Name: "Kruger" }], }; const person3 = { first_name: "john", last_name: "doe", houses: [ { house_name: "Kruger", phone_numbers: [{ ext_code: "+54", phone_number: 232242323 }], }, ], };

const formatName = (str) => {
  return str
    .split("_")
    .map(
      (w, index) =>
        (index > 0 ? w[0].toUpperCase() : w[0].toLowerCase()) + w.substring(1)
    )
    .join("");
};

const formatNames = (input) => {
  if (Array.isArray(input)) {
    return input.map((item) => formatNames(item));
  } else if (typeof input === "object") {
    return Object.fromEntries(
      Object.entries(input).map(([key, value]) => [
        formatName(key),
        formatNames(value),
      ])
    );
  }
  return input;
};

console.log(formatNames(person1));
console.log(formatNames(person2));
console.log(formatNames(person3));

Note: If you made formatName function an argument to formatNames then formatNames is much more flexible as it can be used to form differently name-formatted objects.

user_85104050

My workaround will be creating a class file something like this

in person.js

class Person {
  constructor(personObj) {
    this.firstName = personObj.first_name,
    this.lastName = personObj.Last_Name,
    this.houses = personObj.Houses;
  }
}

const person1 = {
  first_name: 'john',
  last_name: 'doe',
  houses: [{ house_name: 'Kruger' }]
}

const formatted = new Person(person1)
user_79968750
Related