AndreyChernykh/dumpjs

Serialize and deserialize any JS objects to JSON

dumpjs

Sometimes you need serialize your objects to JSON and deserialize them back again. But JSON stringify/parse is not enough, because you need support circular links and restore custom object.

Dumpjs allow easily serialize to JSON and restore any object.

Main points:

• It handle circular links
• Preserve object identities
• Works with any level of nesting objects
• Support custom serialization/deserialization handlers

It use ES6 collections internally and need polyfill in old browsers.

API

D.dump(target[,options]) -> JSON

Target

Plain object or array which need to be serialized.

Options

options.serializer(key, value) — custom serialization function

• If function returns undefined, then property will be ignored. Any other returned value will be serialized. If function returns null, then property will be serialized as null (JSON.stringify converts undefined to null).
• Memorizes received value and invocation result. For the same value always return the same result.

D.restore(source[,options]) -> Object|Array

Source

Valid JSON for deserialization

Options

options.deserializer(key, value) – custom deserialization

• Memorizes received value and invocation result. For the same value always return the same result.

Examples

Circular links

var obj = {x: 1, y: {h: 'hello'}};
obj.y.o = obj;

JSON.stringify(obj); 
// TypeError: Converting circular structure to JSON

var D = require('dumpjs');
D.dump(obj);
// {
//   "@0": {
//     "x": 1, "y": "@1"
//   },
//   "@1": {
//     "h": "hello", "o": "@0"
//   }
// }

Dumpjs creates IDs for every object and use them as references.

Preserve identities

var obj2 = {x: 1, y: 2};
var obj3 = [obj2, obj2];
var restored = JSON.parse(JSON.stringify(obj3));
restored[0] === restored[1]; // false

JSON.parse create completly different objects.

var restored = D.restore(D.dump(obj3));
restored[0] === restored[1]; // true

Custom serializers/deserializers

var obj = {m: new Map ([['a', 1], ['b', 2]])};

function mapSerializer (key, obj) {
    if (obj instanceof Map) return {
        entries: [...obj],
        '__meta__': 'ES6Map'
    };

    return obj;
}

// {
//   "@0": {"map": "@1"},
//   "@1": {"entries": "@2", "__meta__": "ES6Map"},
//   "@2": ["@3", "@4"],
//   "@3": ["a", 1],
//   "@4": ["b", 2]
// }

function mapDeserializer (key, obj) {
    if (obj && obj['__meta__'] === 'ES6Map') {
        return new Map(obj.entries);
    }

    return obj;
}

var json = D.dump(obj, {serializer: mapSerializer});
var restored = D.restore(json, {deserializer: mapDeserializer});

Install

npm install --save dumpjs

Works in node and browser.