json-schema-orm v0.1.0

json-schema-orm

Object-relational mapping from JSON Schema data.

It's not perfect yet, but already working.

See test data files and how we use them in our tests.

Basic usage

Let's say you have JavaScript/JSON objects like these:

{
	"name": "Test data",
	"date": "2013-09-02T05:48:41",
	"points": [
		{"x":10, "y":20},
		{"x":20, "y":30},
		{"x":30, "y":40}
	]
}

And JSON schema for that data:

{
	"title": "Point Collection JSON Schema",
	"oneOf": [
		{ "$ref": "#/definitions/PointCollection" }
	],
	"definitions": {
		"PointCollection": {
			"type": "object",
			"properties": {
				"name": { "type": "string" },
				"date": { "$ref": "#/definitions/Date" },
				"points": {
					"type": "array",
					"items": { "$ref": "#/definitions/Point" },
					"minItems": 1
				}
			},
			"required": ["points"]
		},
		"Date": {
			"type": "string",
			"pattern": "^[0-9]{4}\\-[0-9]{2}\\-[0-9]{2}T[0-9]{2}:[0-9]{2}:[0-9]{2}$"
		},
		"Point": {
			"type": "object",
			"properties": {
				"x": { "type": "number" },
				"y": { "type": "number" }
			}
		}
	}
}

Because everything cannot be done automatically you can create helper file to define specializations:

module.exports = {
	'constructors': {
		'Date': function(opts) {
			return new Date(opts);
		}
	},
	'methods': {
		'Point': function(Point, types) {
			Point.prototype.toString = function() {
				return '[object Point('+ this.x + ',' + this.y + ')]';
			};
		},
		'PointCollection': function(PointCollection, types) {
			PointCollection.prototype.push = function(point) {
				/* ... */
			};
		}
	}
};

Then you can use json-schema-orm to build constructors:

var schema = JSON.parse(fs.readFileSync(__dirname + '/schema.json', {'encoding':'utf8'}));
var schema_orm = require('./orm.js');
var orm = require('json-schema-orm').build({'orm': schema_orm, 'schema':schema});

var PointCollection = orm.PointCollection;
var Point = orm.Point;

After that the constructors can be used the same way as usually:

var collection = new PointCollection({   
    "name": "Test data",
    "date": "2013-09-02T05:48:41",
    "points": [
        {"x":10, "y":20},  
        {"x":20, "y":30},
        {"x":30, "y":40}
	]
});

var point = Point({x:100,y:200});
console.log( point.x ); // 100
console.log( point.y ); // 200
collection.push(point);

License

The MIT license, see LICENSE.