var SomeObj = {
    onchange: Array(),

    createAttribute: function createAttribute(attrName, value) {
        this[attrName] = value;
        for (var i = 0; i < this.onchange.length; i++) {
            this.onchange[i]();
        }
    },
    addCallback: function addCallback(callback) {
        this.onchange.push(callback);
    }

}