fromJson static method

Config? fromJson(dynamic value)

Returns a new Config instance and imports its values from value if it's a Map, null otherwise.

Implementation

// ignore: prefer_constructors_over_static_methods
static Config? fromJson(dynamic value) {
  if (value is Map) {
    final json = value.cast<String, dynamic>();

    // Ensure that the map contains the required keys.
    // Note 1: the values aren't checked for validity beyond being non-null.
    // Note 2: this code is stripped in release mode!
    assert(() {
      requiredKeys.forEach((key) {
        assert(json.containsKey(key), 'Required key "Config[$key]" is missing from JSON.');
        assert(json[key] != null, 'Required key "Config[$key]" has a null value in JSON.');
      });
      return true;
    }());

    return Config(
      maxAge: mapValueOfType<String>(json, r'max_age'),
      maxBytes: mapValueOfType<int>(json, r'max_bytes'),
      maxMsgSize: mapValueOfType<int>(json, r'max_msg_size'),
      maxMsgs: mapValueOfType<int>(json, r'max_msgs'),
      name: mapValueOfType<String>(json, r'name'),
      numReplicas: mapValueOfType<int>(json, r'num_replicas'),
      retention: mapValueOfType<String>(json, r'retention'),
      storage: mapValueOfType<String>(json, r'storage'),
      subjects: json[r'subjects'] is Iterable
          ? (json[r'subjects'] as Iterable).cast<String>().toList(growable: false)
          : const [],
    );
  }
  return null;
}