Meteor defineReactiveProperty() method

object.js

/*
 * @function
 * @name Object.defineReactiveProperty
 * @description define Reactive property:
 *      - set callback before Setter and Getter
 *      - set callback on Setter
 *      - set callback on Getter
 *
 * @param {object} target       - Object on which we define a property
 * @param {string} prop         - Name of defining property
 * @param {mix} value           - Assigned value to newly created property
 * @param {function} callback   - callback function with two parameters:
 *       @param {string} prop           - property name to be defined or modified
 *       @param {mix} currentValue      - Current value of object's property
 *       @param {object} target         - The object we working with
 *
 * @param {function} getCallback - Callback function on object's property Getter, with two parameters:
 *       @param {string} prop           - property name to be defined or modified
 *       @param {mix} currentValue      - Current value of object's property
 *
 * @param {function} setCallback - Callback function on object's property Setter, with two parameters:
 *       @param {string} prop           - property name to be defined or modified
 *       @param {mix} currentValue      - New (created || modified) value of object's property
 *
 */
Object.defineReactiveProperty = function (target, prop, value, callback, getCallback, setCallback) {

    var currentValue = (value) ? value : (target[prop]) ? target[prop] : ' ';
    callback && callback(prop, currentValue, target);

    Object.defineProperty(target, prop, {
        get: function () {

            if(getCallback){
                return getCallback(prop, currentValue);
            }else{
                return currentValue;
            }
        },

        set: function (newValue) {

            if(JSON.stringify(newValue) !== JSON.stringify(currentValue)) {
                currentValue = newValue;
                setCallback && setCallback(prop, currentValue);
            }
        }
    });
};