alphaCharactersValidator static method

String? alphaCharactersValidator(
  1. String? value, [
  2. String? errorMessage
])

alphaCharactersValidator to validate if a form field contains only alphabets

validator: (value) => SimpleValidations.alphaCharactersValidator(value, [errorMessage]),

Implementation

static String? alphaCharactersValidator(String? value,
    [String? errorMessage]) {
  RegExp regex = CustomRegEx.alphaRegex;
  if (value == null || value.isEmpty) {
    return errorMessage ?? 'Required';
  }

  if (!regex.hasMatch(value)) {
    return errorMessage ?? 'Only alphabets are allowed';
  }

  return null;
}