final RegExp _emailRegex = new RegExp(
    r'^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$');

bool isEmail(email) {
  return _emailRegex.hasMatch(email);
}

final RegExp _url = new RegExp(
    r'https?:\/\/((([a-zA-Z0-9.\-\_]+)\.[a-zA-Z]+)|(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}))(:[0-9]+)?');

bool isUrl(url) {
  return _url.hasMatch(url);
}