public static function init($config = NULL)
{
self::$extensions = array();
if (is_null($config)) {
$config = MANIFEST . '/extensions.xml';
}
if (!file_exists($config)) {
self::$extension_configuration = new SimpleXMLElement('<extensions></extensions>');
} else {
$previous = libxml_use_internal_errors(true);
self::$extension_configuration = simplexml_load_file($config);
libxml_use_internal_errors($previous);
if (!self::$extension_configuration instanceof SimpleXMLElement) {
throw new ExtensionException('Failed to load Extension configuration file ' . $config);
}
}
}