Knockout BindingHandler for jQuery UI sortalble

sortableListBindingHandler.js

ko.bindingHandlers.sortableList = {
    init: function (element, valueAccessor, allBindings) {
        var items = allBindings.get('items') || 'li';
        var update = allBindings.get('update') || 'Index';
        var disable = allBindings.get('disable') || false;

        $(element).sortable({
            items: items,
            update: function ($e, $ui) {
                $ui.item.parent().children(items).each(function (k, v) {
                    var data = ko.dataFor(v);

                    if (typeof data[update] === 'function') {
                        data[update](k);
                    } else {
                        data[update] = k;
                    }
                });
            }
        }).sortable({ disabled: disable });
    },
    update: function (element, valueAccessor, allBindings) {
        var disable = allBindings.get('disable') || false;
        $(element).sortable({ disabled: disable });
    }
};

demo @ JSFiddle: http://jsfiddle.net/mt3b4/2/