Unable to parse binding attribute

https://groups.google.com/d/topic/knockoutjs/0LvK7gF9KBQ/discussion

by chrisloughnane

HTML

<script src="https://github.com/jquery/jquery-tmpl/raw/master/jquery.tmpl.js"></script>
<script src="http://knockoutjs.com/downloads/knockout-2.2.1.js"></script>
First name: <input data-bind="valueWithInit: 'firstName'" /><br/>
Last name: <input data-bind="valueWithInit: 'lastName'"/>

<hr/>
<div data-bind="text: ko.toJSON(viewModel) "></div>

CSS

input { margin: 2px; }

JavaScript

var viewModel = {
};

    
//create an observable if it does not exist and populate it with the input's value
ko.bindingHandlers.valueWithInit = {
    init: function(element, valueAccessor, allBindingsAccessor, data) {
        var property = valueAccessor(),
            value = element.value;

        //create the observable, if it doesn't exist 
        if (!ko.isWriteableObservable(data[property])) {
            data[property] = ko.observable();
        }

        data[property](value);

        ko.applyBindingsToNode(element, { value: data[property] });
    }
}

ko.applyBindings(viewModel);