function execute(&$controller, &$request, &$user)
{
$uri = $request->getParameter('uri');
$feed = new FeedParser($uri);
$response = '';
if ($feed->isValid() === false) {
$response = 'false';
} else {
$response = 'true';
}
header('Content-Type: text/plain; charset=utf-8');
echo $response;
return VIEW_NONE;
}