robianmcd/index.html

## index.html
<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
    <input id="myInput" type="checkbox"/>

    <script>
        if (!Object.prototype.watch) {
            Object.defineProperty(Object.prototype, "watch", {
                enumerable: false
                , configurable: true
                , writable: false
                , value: function (prop, handler) {
                    var
                            oldval = this[prop]
                            , newval = oldval
                            , getter = function () {
                                return newval;
                            }
                            , setter = function (val) {
                                oldval = newval;
                                return newval = handler.call(this, prop, oldval, val);
                            }
                            ;

                    if (delete this[prop]) { // can't watch constants
                        Object.defineProperty(this, prop, {
                            get: getter
                            , set: setter
                            , enumerable: true
                            , configurable: true
                        });
                    }
                }
            });
        }

        // object.unwatch
        if (!Object.prototype.unwatch) {
            Object.defineProperty(Object.prototype, "unwatch", {
                enumerable: false
                , configurable: true
                , writable: false
                , value: function (prop) {
                    var val = this[prop];
                    delete this[prop]; // remove accessors
                    this[prop] = val;
                }
            });
        }

        var e = document.getElementById('myInput');
        e.watch('checked', function () {
            console.log('changed');
        });
    </script>
</body>
</html>
	<!DOCTYPE html>
	<html>
	<head lang="en">
	<meta charset="UTF-8">
	<title></title>
	</head>
	<body>
	<input id="myInput" type="checkbox"/>

	<script>
	if (!Object.prototype.watch) {
	Object.defineProperty(Object.prototype, "watch", {
	enumerable: false
	, configurable: true
	, writable: false
	, value: function (prop, handler) {
	var
	oldval = this[prop]
	, newval = oldval
	, getter = function () {
	return newval;
	}
	, setter = function (val) {
	oldval = newval;
	return newval = handler.call(this, prop, oldval, val);
	}
	;

	if (delete this[prop]) { // can't watch constants
	Object.defineProperty(this, prop, {
	get: getter
	, set: setter
	, enumerable: true
	, configurable: true
	});
	}
	}
	});
	}

	// object.unwatch
	if (!Object.prototype.unwatch) {
	Object.defineProperty(Object.prototype, "unwatch", {
	enumerable: false
	, configurable: true
	, writable: false
	, value: function (prop) {
	var val = this[prop];
	delete this[prop]; // remove accessors
	this[prop] = val;
	}
	});
	}

	var e = document.getElementById('myInput');
	e.watch('checked', function () {
	console.log('changed');
	});
	</script>
	</body>
	</html>