PHP Wikipedia XML

I'm just wondering how I can make the following code work? Thanks.

<?php
    $url = 'http://ift.tt/X14ZD2';
    $xml = new SimpleXMLElement(file_get_contents($url));
    if ($xml->mediawiki->page->redirect->attributes()['title']) {
        echo $xml->mediawiki->page->redirect->attributes()['title'];
    } else if ($xml->mediawiki->page->title) {
        echo $xml->mediawiki->page->title;
    } else {
        echo "Not a valid Wikipedia page!";
    }
?>