protected function renderFile($_sfFile)
{
$info = pathinfo($_sfFile);
$base = "{$info['dirname']}/{$info['filename']}";
$filename = $base . ucfirst(strtolower(sfJpMobile::getCarrierName())) . '.' . $info['extension'];
if (!is_readable($filename)) {
$filename = "{$base}Mobile.{$info['extension']}";
if (!sfJpMobile::isMobile() || !is_readable($filename)) {
$filename = $_sfFile;
}
}
return parent::renderFile($filename);
}