public function expand($shortcode)
{
// remove the 1 we added when we created it
$index = ShortUrl::decode($shortcode) - 1;
if ($index == -1) {
return NULL;
}
$urls = $this->storage->getYAML('urls');
$url_data =& $urls[$index];
$url_data['clicks']++;
$this->storage->putYAML('urls', $urls);
return $url_data['url'];
}