jsのデータモデリング、イベントハンドリングを面白く

observe.js

var each = function(obj, callback) {
	for(var p in obj) {
		if(!obj.hasOwnProperty(p)) continue;

		callback(p, obj[p]);
	}
};

var Model = (function() {
	function Model(params) {
		each(params, function(prop, value) {
			this[prop] = value;
		}.bind(this));
	}

	Model.extend = function(defines) {
		var cls = function() {};

		cls.prototype.scheme = {};
		each(defines.scheme, function(prop, value) {
			cls.prototype.scheme[prop] = value;

			Object.defineProperty(cls.prototype, prop, {
				get: function() {
					return this.scheme[prop];
				},
				set: function(val) {
					var old = this.scheme[prop];

					if(old !== val) {
						console.log('change: ' + prop + ' = ' + val + ', old = ' + old);
					}
					this.scheme[prop] = val;
				}
			});
		});

		console.log(cls.prototype.scheme);

		return cls;
	};

	return Model;
}());

var Human = Model.extend({
	scheme: {
		id: -1,
		name: 'John Smith',
		age: 21,
		sex: 'male'
	}
});

var h = new Human();
h.id = 1;