public function isAsset(CakeRequest $request)
{
$dirs = array('css', 'js', 'img');
$exts = array('css', 'js', 'gif', 'jpg', 'jpeg', 'png', 'ico', 'svg', 'swf');
$dirRegex = implode('|', $dirs);
$extRegex = implode('|', $exts);
$assetRegex = '/^(' . $dirRegex . ')\\/.+\\.(' . $extRegex . ')$/';
$themeAssetRegex = '/^theme\\/[^\\/]+?\\/(' . $dirRegex . ')\\/.+\\.(' . $extRegex . ')$/';
$uri = $request->url;
return preg_match($assetRegex, $uri) || preg_match($themeAssetRegex, $uri);
}