Knockout Blog Post: http://blog.osbornm.com/2013/02/27/knockout-widget-binding/ ‎

Example.html

<!-- Simple Binding -->
<input type="submit" value="OK" data-bind='widget: "button"' />
<!-- Complex Binding with options -->
<input id='search' data-bind='widget: { name: "autocomplete", options: { source: searchCompletions(), delay: 500 } }, value: searchString' />

ko.bindings.widget.js

ko.bindingHandlers.widget = {
    update: function (element, valueAccessor, allBindingsAccessor) {
        var widgetBindings = _getWidgetBindings(element, valueAccessor, allBindingsAccessor);
        $(element)[widgetBindings.widgetName](widgetBindings.widgetOptions);
    }
};

function _getWidgetBindings(element, valueAccessor, allBindingsAccessor) {
    var value = valueAccessor(),
        myBinding = ko.utils.unwrapObservable(value),
        allBindings = allBindingsAccessor();

    if (typeof (myBinding) === 'string') {
        myBinding = { 'name': myBinding };
    }

    var widgetName = myBinding.name,
        widgetOptions = myBinding.options;

    // Sanity check: can't directly check that it's truly a _widget_, but
    // can at least verify that it's a defined function on jQuery:
    if (typeof $.fn[widgetName] !== 'function') {
        throw new Error("widget binding doesn't recognize '" + widgetName + "' as jQuery UI widget");
    }

    // Sanity check: don't confuse KO's 'options' binding with jqueryui binding's 'options' property
    if (allBindings.options && !widgetOptions && element.tagName !== 'SELECT') {
        throw new Error("widget binding options should be specified like this:\ndata-bind='widget: {name:\"" + widgetName + "\", options:{...} }'");
    }

    return {
        widgetName: widgetName,
        widgetOptions: widgetOptions
    };
}