url static method

Implementation

static FormFieldValidator url(
    {String errorText = "This field requires a valid URL address.",
    List<String> protocols = const ['http', 'https', 'ftp'],
    bool requireTld = true,
    bool requireProtocol = false,
    bool allowUnderscore = false,
    List<String> hostWhitelist = const [],
    List<String> hostBlacklist = const []}) {
  return (valueCandidate) {
    if (valueCandidate is String && valueCandidate.isNotEmpty) {
      if (!isURL(valueCandidate,
          protocols: protocols,
          requireTld: requireTld,
          requireProtocol: requireProtocol,
          allowUnderscore: allowUnderscore,
          hostWhitelist: hostWhitelist,
          hostBlacklist: hostBlacklist)) return errorText;
    }
    return null;
  };
}