knockoutjs databind with jquery controls

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

by Princa

HTML

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.11/themes/base/jquery-ui.css">
<script src="http://knockoutjs.com/downloads/knockout-2.2.1.js"></script>
<script src="http://cdnjs.cloudflare.com/ajax/libs/datejs/1.0/date.min.js"></script>
<input data-bind="datepicker: myDate, datepickerOptions: { minDate: new Date() }, text: myDate" />

<hr />

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

<hr />

<div data-bind="text: myDate"></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 optional options
        var options = allBindingsAccessor().datepickerOptions || {};
        $(element).datepicker(options);

        //handle the field changing
        ko.utils.registerEventHandler(element, "change", function() {
            var observable = valueAccessor();
            var date= Date.parse($(element).val());
            observable(date.toString("MM/dd/yyyy"));
            //observable($(element).datepicker("getDate"));
        });

        //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()),
            current = $(element).datepicker("getDate");
        var d = Date.parse(value);
        if (value - current !== 0) {
            $(element).datepicker("setDate", d.toString("MM/dd/yyyy"));   
        }
    }
};

var viewModel = {
    myDate: ko.observable(new Date("09/01/2011").toString("MM/dd/yyyy")),
    setToCurrentDate: function() {
        this.myDate(new Date().toString("MM/dd/yyyy"));
    }
};

ko.applyBindings(viewModel);