shadowjson v1.0.0

ShadowJson

A small utility class that helps to generate path-specific and manageable JSON object copy

Why

In many dev cases, we have to keep an original JSON object while having another deep copied object for editing. Simply deep copying the whole object can lead to unnecessary memory usage and hard management with the original data. ShadowJson solves these problems by following features: 1. allow path-specific clone 2. easy commit/discard changes 4. small implementation (476 bytes) 3. support CJS, ESM and UMD

Install

npm install --save ShadowJson

Usage

const ShadowJson = require('ShadowJson');

let source = { a: 1, b: '2', c: { d: 5 } };

// create ShadowJson with initial path 'c'
let shadow = new ShadowJson(source, ['c']);

// edit the shadow copy
// modify path 'c.d'
shadow.set('c.d', {x: 7});

// delete path 'b'
shadow.set('b', undefined);

// add path 'z'
shadow.set('z', 3);

// change to path 'b' is discarded
shadow.discard('b');

// commit the rest of the changes
shadow.commit();

console.log(source); // { a: 1, b: '2', c: { d: { x: 7 } }, z: 3 }

API

ShadowJson(obj, paths)

The ShadowJson constructor. Returns Object.

Note: Avoid using '.' or '' as object keys in the source data.

get(path)

Get the value of a copied path. Returns Any.

set(path, val)

Set the value of a path. Returns void.

commit(path)

Commit the changes to the source data. Returns void.

Note: If changes are made to a path and its subpath, the most recent path change will override.

discard(path)

Discard changes made to ShadowObject. Returns void.

License

MIT