JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://code.jquery.com/jquery-1.11.0.min.js"></script>
<div id="test" data-bind="attr: {'data-area': area() + 1 }">Hover for title</div>
<a href="#" onClick="alert($('#test')[0].getAttribute('data-area') + '/'+$('#test').data('area'));">Test!</a>

JavaScript

ViewModel = function() {
    this.area = ko.observable(0);
    setInterval(function() {
        this.area(this.area() + 1);
    }.bind(this), 1000);
};

ko.applyBindings(new ViewModel());