getFilenameExtension static method
Extract file extension from path
Implementation
static String? getFilenameExtension(String? path) {
if (path == null) return null;
final extIndex = path.lastIndexOf('.');
if (extIndex == -1) return null;
final folderIndex = path.lastIndexOf('/');
if (folderIndex > extIndex) return null;
return path.substring(extIndex + 1);
}