validateField method

String? validateField(
  1. String? text, {
  2. required String fieldName,
  3. bool isEmail = false,
})

Implementation

String? validateField(String? text,
    {required String fieldName, bool isEmail = false}) {
  if (text == null || text.isEmpty) {
    return '$fieldName is required';
  }
  if (isEmail && !text.isEmail) {
    return 'Has to be a valid email address.';
  }
  return null;
}