validateResponse method

FreeTextValidationError? validateResponse(String input)

Implementation

FreeTextValidationError? validateResponse(String input) {
  // For non-custom text types, length is checked before type.
  if (textType != FreeTextQuestionType.custom) {
    final minLength = lengthRange.first;
    if (input.isEmpty && minLength == 0) {
      return null;
    }
    if (input.length < minLength) {
      return FreeTextValidationError.tooShort;
    }
    if (input.length > lengthRange.last) {
      return FreeTextValidationError.tooLong;
    }
  }

  switch (textType) {
    case FreeTextQuestionType.any:
      return null;
    case FreeTextQuestionType.alphanumeric:
      if (RegExp(alphanumericPattern).hasMatch(input)) {
        return null;
      }
      return FreeTextValidationError.notAlphanumeric;
    case FreeTextQuestionType.numeric:
      if (RegExp(r'^-?[0-9]+$').hasMatch(input)) {
        return null;
      }
      return FreeTextValidationError.notNumeric;
    case FreeTextQuestionType.custom:
      final expression = customTypeExpression;
      if (expression == null || expression.isEmpty) {
        return FreeTextValidationError.invalidCustomExpression;
      }
      try {
        final regex = RegExp('^(?:$expression)\$');
        if (regex.hasMatch(input)) {
          return null;
        }
        return FreeTextValidationError.customMismatch;
      } on FormatException {
        return FreeTextValidationError.invalidCustomExpression;
      }
  }
}