FlattenJS

A small simple library to easily flatten / unflatten JSON objects. Uses square brackets in path to preserve arrays.

The path format works the same as RSPath.

Installation

npm install flattenjs --save

Updates

• 2.1.0: Added opt-in 'preserveEmpty'. Updated lodash dependency. @adil

Usage

import { flatten, inflate } from 'flattenjs'

// Simple

var obj = {
    a: true
};

var flattened = flatten(obj);
console.log(flattened);
// { a: true }

var unflattened = inflate(flattened);
console.log(unflattened);
// { a: true }

// Arrays

obj = {
    a: true,
    b: {
        ba: [],
        bb: [0, 1, 2, 3, 4]
    }
};

flattened = flatten(obj);
console.log(flattened);
// {
//     'a': true,
//     'b.bb[0]': 0,
//     'b.bb[1]': 1,
//     'b.bb[2]': 2,
//     'b.bb[3]': 3,
//     'b.bb[4]': 4
// }

unflattened = inflate(flattened);
console.log(unflattened);
// { a: true, b: { bb: [ 0, 1, 2, 3, 4 ] } }

// Arrays and Objects

obj = {
    a: true,
    b: {
        ba: [{
            baa: [0, 1, 2, 3, 4]
        }, {
            bab: [0, 1, 2, 3, 4]
        }]
    }
};

flattened = flatten(obj);
console.log(flattened);
// {
//     'a': true,
//     'b.ba[0].baa[0]': 0,
//     'b.ba[0].baa[1]': 1,
//     'b.ba[0].baa[2]': 2,
//     'b.ba[0].baa[3]': 3,
//     'b.ba[0].baa[4]': 4,
//     'b.ba[1].bab[0]': 0,
//     'b.ba[1].bab[1]': 1,
//     'b.ba[1].bab[2]': 2,
//     'b.ba[1].bab[3]': 3,
//     'b.ba[1].bab[4]': 4
// }

unflattened = inflate(flattened);
console.log(unflattened);

Preserve Empty Objects/Arrays

This is now available as an opt-in option in [email protected]. Set the second parameter to 'flatten(obj, true)' to enable the preserveEmpty capability.

var Flatten = require('./flatten');

var test = {
    a: { 
        b: 1, 
        c: [], 
        d: {},
        f: [{ g: {} }]
    },
    e: {}
};

var flattened = Flatten.flatten(test, true);
console.log(JSON.stringify(flattened, undefined, 2));

var inflated = Flatten.inflate(flattened);
console.log(JSON.stringify(inflated, undefined, 2));