json4all v1.4.0

json4all

JSON for all purposes and all platforms

language: also available in:

Install

$ npm install json4all

Main goal

Replace JSON by a function that

• can encode/decode:
  • Date
  • Regexp
  • Objects and Arrays that contains undefined
  • User defined types
• be sure, ie dont encode Function
• have a way to exchange objects between the front-end and the back-end:
  • sending to the front-end only the properties that the front-end must known,
  • sending to the front-end a reference to the instance of that object in the back-end

var JSON4all = require('json4all');

var today = new Date();
var tansDate = JSON4all.parse(JSON4all.stringify(today));
console.log(transDate.constructor.name); // Date

JSON4all.addType(Constructor)

Registers the class constructor

Te class must have these functions:

• JSON4replacer (at prototype level) thats returns a recreate value
• JSON4reviver (at class level) that receives the recreate value and returns the recreated object.

var JSON4all = require('json4all');

function Point(x, y, z) {
    this.klass = 'Point';
    this.x     = x;
    this.y     = y;
    this.z     = z;
}

Point.prototype.JSON4replacer=function(){ return {x:this.x, y:this.y, z:this.z}; }
Point.JSON4reviver=function(o){ return new Point(o.x, o.y, o.z); }

JSON4all.addType(Point);

var p = new Point();
var q = JSON4all.parse(JSON4all.stingify(p));

console.log(q instanceof Point); // true

@JSON4all.addClass

Decorator that registers the class

You must define with addProperty with properties you want to serialize. If a property is in the class main constructor you must use addProperty(n) (startin with 1).

var JSON4all = require('json4all');

@JSON4all.addClass
class Point {
    @JSON4all.addProperty(1) public x: number
    @JSON4all.addProperty(2) public y: number
    @JSON4all.addProperty(3) public z: number
    @JSON4all.addProperty public color: string | undefined
    public internal: number | undefined
    constructor(x, y, z){
        this.x = x;
        this.y = y;
        this.z = z;
    }
}

var p = new Point(1.1, 2.3, 3.14);
p.internal = 7;

var q = JSON4all.parse(JSON4all.stingify(p));

console.log(q.internal); // undefined
console.log(q instanceof Point); // true
console.log(q.z); // 3.14

JSON4all.RefStore

Registers an object as a repository of referenciable instances in the back-end that can send copies to the front-end.

When a object is serialized in the back-end a reference was added to the sended data. In the front-end the object is revived and the reference conserved.

When the object is serialized to be send back to de back-end, it serialize only the reference excluding the properity values (because they don't need id to identified the object in the back-end).

// in the back-end
import * as JSON4all from 'json4all';
import { Point } from './common/my-classes';

JSON4all.RefStoreSpace(global.mySpace)

var points = JSON4all.RefStore<string, Point>(['points']);

var center = new Point(100,200,-50);
points['x3298484'] = center;

console.log(points[JSON4all.RefKey]) // 'x3298484'
var str = JSON4all.stringify(center);

var center2 = JSON4all.parse(str);

console.log( center === center2 ); // true the same instance!!!!

res.send(JSON4all.stringify(center));

// IN THE FRONT-END:
import * as JSON4all from 'json4all';
import { Point } from './common/my-classes';

var pointStr = await simpleFetch('https://..../center')
var point = JSON4all.parse()

console.log(point.x, point.y, point.z); // 100,200,-50
point.x = 999;

simpleFetch('https://..../set-center?point='+JSON4all.stringify(point));
// only the ref is sended

// IN THE BACK-END:

app.get('/set-center',(req)=>{
    // with the ref the object is retrived from the collection
    var point = JSON4all.parse(req.query('point'));
    console.log(point.x, point.y, point.z); // 100,200,-50
    console.log(points['x3298484'] === point) // the same instance
})

JSON4all.pretendClass(object, classConstructor)

Sets internal properties of a plain object to make the call of JSON.stringify(object) to return the same value that the call aplied to a instance object of that class with the same values (JSON.stringify(object) === JSON.object(instance)).

var point = new Point({x:7, y:8});
var object = {x:7, y:8};

JSON4all.pretendClass(object, Point);

console.log(JSON4all.stringify(object) == JSON4all.stringify(point)); // true

var restoredPoint = JSON4all.parse(JSON4all.stringify(object));

console.log(restoredPoint instanceof Point); // true

Tests with real devices

License

MIT