replicator

Advanced JavaScript objects serialization

• Can serialize circular references
• In addition to JSON-serializable types can serialize:
  • undefined
  • NaN
  • Date
  • RegExp
  • Error¹
  • Map²
  • Set³
  • ArrayBuffer³
  • Typed arrays³
• Can be extended with custom type transforms
• Can use any target serializer under the hood (JSON, BSON, protobuf, etc.)

---

1: If decoding target platform doesn't support encoded error type, it will fallback to Error constructor.
2: If decoding target platform doesn't support Map, it will be decoded as array of [key, value].
3: If decoding target platform doesn't support Set, ArrayBuffer or typed arrays, they will be decoded as array.

Install

npm install replicator

Usage

const Replicator = require('replicator');

const replicator = new Replicator();

const a = {};
a.b = a;

const str = replicator.encode({
    key1: new Set([1, 2, 3]),
    key2: /\s+/ig,
    key3: a
});

const obj = replicator.decode(str);

Adding custom types support

You can extend replicator with custom type transform which will describe how to serialize/deserialize objects. You can add transforms using .addTransforms(transforms) method. And remove them using .removeTransforms(transforms) method. Both methods are chainable and accept single transform or array of transforms. You should add transforms to both encoding and decoding instances of replicator.

Let's create transform which will encode NodeList of elements and decode it as array of objects with tagName property:

const Replicator = require('replicator');

const replicator = new Replicator();

replicator.addTransforms([
    {
        type: 'NodeList',

        shouldTransform (type, val) {
            return typeof NodeList === 'function' && val instanceof NodeList;
        },

        toSerializable (nodeList) {
            // We should transform NodeList to primitive serializable object.
            // It's an array of HTMLElement in our case.
            // Note that it's not required to transform each element in
            // NodeList. We can add HTMLElement transform which
            // will transform NodeList items and individual elements as well.
            return Array.prototype.slice.call(nodeList);
        },

        fromSerializable (val){
            // Now we should describe how to restore NodeList from serializable object.
            // In our case we just need an array so we'll return it as is.
            // If you want to restore it as NodeList you can create document fragment, append
            // array contents to it and return result of `fragment.querySelectorAll('*')` .
            return val;
        }
    },

    {
        type: 'Element',

        shouldTransform (type, val){
            return typeof HTMLElement === 'function' && val instanceof HTMLElement;
        },

        toSerializable (element) {
            return element.tagName;
        },

        fromSerializable (val) {
            return { tagName: val };
        }
    }
]);

var str = replicator.encode(document.querySelectorAll('div'));

console.log(replicator.decode(str));
// > [ { tagName: 'div'}, { tagName: 'div'}, { tagName: 'div'}]

Built-in types support implemented using transforms, so you can take a look on replicator source code for more examples.

Changing serialization format

By default replicator uses JSON under the hood. But you can use any serializer by passing serializer adapter to Replicator constructor. E.g., let's use BSON as serializer:

const Replicator = require('replicator');
const BSON       = require('bson');

const replicator = new Replicator({
    serialize (val) {
        return BSON.serialize(val, false, true, false);
    },

    deserialize: BSON.deserialize
});

replicator.encode(['yo', 42]);
// > <Buffer>

Author

Ivan Nikulin ([e-mail])