flashMessage method
Implementation
Future flashMessage(String reason, var message) async {
if(reason.isNotEmpty && message!=''){
final cookie = Cookie(reason, message.toString());
DateTime now = new DateTime.now().toLocal();
DateTime date = new DateTime(now.year, now.month, now.day, now.hour, now.minute, now.second, now.microsecond+1000);
cookie.httpOnly = false;
cookie.expires = date;
res?.cookies.add(cookie);
}else{
throw CustomException('[ Error ] Either one of two data is not supplied!').showError();
}
}