omod 2

Modify javascript objects recursively with pipeable node modifier functions

You can use this library for modifying any object in javascript including arrays and collections.

Those functions were initially created to translate figmaTokens JSON format to style-dictionary. Its purpose was to unify all values and resolve references.

Since it is quite extensible and pipeable, I decided to publish it as a standalone npm package.

Quick start

$ yarn add omod

Then in your file:

const { omod } = require('omod');

[...]

const modifiedObject = omod(inputObject, modifierFn)

omod

Omod runs modifier function for each node of the object recursively, doesn't matter if it is nested object, collection or primitives array. Therefore, it's up to modifier, what it is going to modify.

omod(inputObject, modifierFn)

• inputObject - object to be modified
• modifierFn - function for modifying nodes of object.

Modifier Function

In modifier function you can modify whole nodes, array items, or primitive values of the object. Your function may test current node, and execute modifications to modify object selectively.

const extractColorValues = (node, path, object) => {
  if (path.includes('colors') && 'value' in node) {
    const color = doSomethingWithColor(node.value);
    
    return {
      originalColor: node.value,
      value: {
        r: color.getR(),
        g: color.getG(),
        b: color.getB(),
        a: color.getA()
      }
    }
  }
  
  return node // has to return node
}

• value - current value to be modified
• path - path to the value in form of array. For example: [ 'colors', 'primary', 4 ]
• object - full initial object

Modifier Pipe

You can also pipe some modifiers using modifierPipe

const { omod, modifierPipe } = require('omod');

const modifierA = [...]
const modifierB = [...]
const modifierC = [...]

const modifiers = modifierPipe(
  modifierA,
  modifierB,
  modifierC
)

const modifiedObject = omod(object, modifiers)

Utility functions

const { isArray, isString, last, get } = require('omod')

get

Fetches value from object using given path

isArray

Checks if given value is array

isArrayItem

Checks if given path is path to array element

isNumber

Checks if given value is number

isObject

Checks if given value is object

isString

Checks if given value is string

last

Gets last element from array

modifierPipe

Creates pipe for given modifiers