dart_extension.dart

dart_extension.dart

/// Example 1
/// Enum extension
enum NetworkState {
  unknown,
  connected,
  disconnected,
}

/// NetworkStateExtension
extension NetworkStateExt on NetworkState {
  static const networkStateNames = [
    'UNKNOWN',
    'CONNECTED',
    'DISCONNECTED',
  ];

  static NetworkState parse(dynamic value) {
    if (value is String) {
      final index = networkStateNames.indexOf(value);
      if (index > -1) {
        return NetworkState.values[index];
      }
    } else if (value is int) {
      return NetworkState.values[value];
    }
    throw 'not found';
  }

  String get name => networkStateNames[index];

  String getName() {
    return networkStateNames[index];
  }
}

/// Example 1
/// UserEntity extension
class UserEntity {
  final String name;
  final String email;
  final int age;

  UserEntity({this.name, this.email, this.age});
}

extension UserEntityExt on UserEntity {
  UserEntity copyWith({String name, String email, int age}) => UserEntity(
        name: name ?? this.name,
        email: email ?? this.email,
        age: age ?? this.age,
      );

  String description() {
    return '$name, $email, $age';
  }
}

void main() {
  final networkState = NetworkStateExt.parse('CONNECTED');
  print(networkState.name);

  final u1 = UserEntity(name: 'Alex', age: 35);
  print(u1.description());
  final u2 = u1.copyWith(name: 'Eugene');
  print(u2.description());
}