GitHub - mariocasciaro/object-path-immutable: Modify deep object properties without modifying the original object (immutability). Works great with React and Redux.

Tiny JS library to modify deep object properties without modifying the original object (immutability). Works great with React (especially when using setState()) and Redux (inside a reducer).

This can be seen as a simpler and more intuitive alternative to the React Immutability Helpers and Immutable.js.

Changelog

View Changelog

Install

npm install object-path-immutable --save

Quick usage

The following, sets a property without modifying the original object. It will minimize the number of clones down the line. The resulting object is just a plain JS object literal, so be warned that it will not be protected against property mutations (like Immutable.js)

const obj = {
  a: {
    b: 'c',
    c: ['d', 'f']
  }
}

const newObj = immutable.set(obj, 'a.b', 'f')
// {
//   a: {
//     b: 'f',
//     c: ['d', 'f']
//   }
// }

// obj !== newObj
// obj.a !== newObj.a
// obj.a.b !== newObj.a.b

// However:
// obj.a.c === newObj.a.c

Wrap mode

You can also chain the api's and call value() at the end to retrieve the resulting object.

const newObj = immutable.wrap(obj).set('a.b', 'f').del('a.c.0').value()

API

// Premises

const obj = {
  a: {
    b: 'c',
    c: ['d', 'f']
  }
}

import * as immutable from 'object-path-immutable'

set (initialObject, path, value)

Changes an object property.

Path can be either a string or an array.

const newObj1 = immutable.set(obj, 'a.b', 'f')
const newObj2 = immutable.set(obj, ['a', 'b'], 'f')

// {
//   a: {
//     b: 'f',
//     c: ['d', 'f']
//   }
// }

// Note that if the path is specified as a string, numbers are automatically interpreted as array indexes.

const newObj = immutable.set(obj, 'a.c.1', 'fooo')
// {
//   a: {
//     b: 'f',
//     c: ['d', 'fooo']
//   }
// }

update (initialObject, path, updater)

Updates an object property.

const obj = {
  a: {
    b: 1
  }
}

const newObj = immutable.update(obj, ['a', 'b'], v => v + 1)

// {
//   a: {
//     b: 2,
//   }
// }

push (initialObject, path, value)

Push into a deep array (it will create intermediate objects/arrays if necessary).

const newObj = immutable.push(obj, 'a.d', 'f')
// {
//   a: {
//     b: 'f',
//     c: ['d', 'f'],
//     d: ['f']
//   }
// }

del (initialObject, path)

Deletes a property.

const newObj = immutable.del(obj, 'a.c')
// {
//   a: {
//     b: 'f'
//   }
// }

Can also delete a deep array item using splice

const newObj = immutable.del(obj, 'a.c.0')
// {
//   a: {
//     b: 'f',
//     c: ['f']
//   }
// }

assign (initialObject, path, payload)

Shallow copy properties.

const newObj = immutable.assign(obj, 'a', { b: 'f', g: 'h' })
// {
//   a: {
//     b: 'f',
//     c: ['d, 'f'],
//     g: 'h'
//   }
// }

insert (initialObject, path, payload, position)

Insert property at the specific array index.

const newObj = immutable.insert(obj, 'a.c', 'k', 1)
// var obj = {
//   a: {
//     b: 'c',
//     c: ['d, 'k' 'f'],
//   }
// }

merge (initialObject, path, value)

Deep merge properties.

const newObj = immutable.merge(obj, 'a.c', {b: 'd'})