For iTunes LP and iTunes Extras content programatically loading a link is very difficult. Both iTunes and AppleTV don’t support the Javascript function windows.open() or the property window.location. I’ve managed to come up with this bypass (aka hack) which is demonstrated in the Javascript code below. It triggers a mouse click event emulating the user manually clicking a link on the page.
//click a link with id 'my_link'
clickLink(document.getElementById('my_link'));
function clickLink(elementId) {
var elm = document.getElementById(elementId);
//set up mouse click event
var evt = document.createEvent('MouseEvents');
evt.initMouseEvent('click', true, true, document.defaultView, 1, 0, 0, 0, 0, false, false, false, false, 0, null);
//trigger click event on html element
elm.dispatchEvent(evt);
}