knockoutjs databind with jquery controls

http://stackoverflow.com/questions/6399078/knockoutjs-databind-with-jquery-controls

by rpallas

HTML

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.11/themes/base/jquery-ui.css">
<script src="https://github.com/downloads/SteveSanderson/knockout/knockout-2.1.0.debug.js"></script>
<script src="https://raw.github.com/timrwood/moment/1.7.2/min/moment.min.js"></script>
<script src="http://code.jquery.com/ui/1.9.1/jquery-ui.js"></script>
<input type="text" data-bind="datepicker: myDate" />
<input type="text" data-bind="hourpicker: myDate" />
<input type="text" data-bind="minutepicker: myDate" />

<hr />

<button data-bind="click: setToCurrentDate">Set To Current Date</button>

<hr />

<div data-bind="text: displayDate"></div>

CSS

td, th { padding: 5px; border: solid 1px black; }
th { color: #666; }
a { font-size: .75em; }

JavaScript

ko.bindingHandlers.datepicker = {
    init: function(element, valueAccessor, allBindingsAccessor) {
        //initialize datepicker with some options (or just  use the defaults)
        var options = allBindingsAccessor().datepickerOptions || {
                dateFormat: 'dd/mm/yy',
                showButtonPanel: true
            };
        $(element).datepicker(options);

        //handle the field changing
        ko.utils.registerEventHandler(element, "change", function () {

            var observable = valueAccessor(),
                newValue = $(element).datepicker("getDate"),
                unixTimestamp = moment(newValue).unix();
            observable(unixTimestamp);
        });

        //handle disposal (if KO removes by the template binding)
        ko.utils.domNodeDisposal.addDisposeCallback(element, function () {
            $(element).datepicker("destroy");
        });

    },
    update: function (element, valueAccessor) {
        var value = ko.utils.unwrapObservable(valueAccessor()),
            newValue = moment.unix(value).toDate(),
            temp = new Date(2001, 8, 11, 8, 25),
            current = $(element).datepicker("getDate");
        if (newValue - current !== 0) {
            $(element).datepicker("setDate", temp);
        }
    }
};

ko.bindingHandlers.hourpicker = {
    init: function(element, valueAccessor, allBindingsAccessor) {
        //handle the field changing
        ko.utils.registerEventHandler(element, "change", function () {
            var currentTimestamp = ko.utils.unwrapObservable(valueAccessor()),
                observable = valueAccessor(),
                newHourValue = $(element).val(),
                // Construct a new date with only the hours changed
                newDate = moment.unix(currentTimestamp).hours(newHourValue);
            var newTimestamp = newDate.unix();
            observable(newTimestamp);
        });
    },
    update: function (element, valueAccessor) {
        // Convert the value...