copyWith is inherited as a getter

[Yogesh-Dubey-Ayesavi]

I making message models my script is

import 'package:freezed_annotation/freezed_annotation.dart';

part 'message.freezed.dart';
part 'message.g.dart';

enum MessageType { text, payment }

abstract class Message {
  final String id;
  final String authorId;
  final Message? repliedMessage;
  final MessageType type;
  final DateTime createdAt;
  final String roomId;
  Message({
    required this.id,
    required this.authorId,
    required this.roomId,
    this.repliedMessage,
    required this.type,
    required this.createdAt,
  });

  factory Message.fromJson(Map<String, dynamic> json) {
    return _$TextMessageFromJson(json);
  }

  Map<String, dynamic> toJson();

  Message copyWith({
    String? id,
    String? authorId,
    Message? repliedMessage,
    MessageType? type,
    DateTime? createdAt,
    String? roomId,
  });
}

@freezed
abstract class TextMessage extends Message with _$TextMessage {
  const factory TextMessage({
    required String text,
    required String authorId,
    required String id,
    required DateTime createdAt,
    Message? repliedMessage,
    required String roomId,
    @Default(MessageType.text) MessageType type,
  }) = _TextMessage;

  factory TextMessage.fromJson(Map<String, dynamic> json) =>
      _$TextMessageFromJson(json);
}

I am having a TextMessage class which extends Message however this says copyWith is inherited as a getter.

can anyone fix this I want the copyWith function.

[JesseRiemens]

Correct, because now you're inheriting the copyWith from both Message, and _$TextMessage. (since the one generated in _$TextMessage will not @override the inherited one. That's why in this case you probably would want a pure interface:

import 'package:freezed_annotation/freezed_annotation.dart';

part 'message.freezed.dart';
part 'message.g.dart';

enum MessageType { text, payment }

abstract interface class Message {
  String get id;
  String get authorId;
  String get roomId;
  Message? get repliedMessage;
  MessageType get type;
  DateTime get createdAt;
}

@freezed
class TextMessage with _$TextMessage implements Message {
  factory TextMessage({
    required String id,
    required String authorId,
    required String roomId,
    @MessageConverter() Message? repliedMessage,
    @Default(MessageType.text) MessageType type,
    required DateTime createdAt,
    required String text,
  }) = _TextMessage;
  const TextMessage._();

  factory TextMessage.fromJson(Map<String, dynamic> json) =>
      _$TextMessageFromJson(json);
}

class MessageConverter implements JsonConverter<Message, Map<String, dynamic>> {
  const MessageConverter();

  @override
  Message fromJson(Map<String, dynamic> json) {
    if (json['type'] == 'text') {
      return TextMessage.fromJson(json);
    }
    throw Exception('Unknown message type');
  }

  @override
  Map<String, dynamic> toJson(Message message) {
    if (message is TextMessage) {
      return message.toJson();
    }
    throw Exception('Unknown message type');
  }
}

Does this work for you?

[JesseRiemens]

Perhaps make message freezed, and give it multiple constructors?

[Yogesh-Dubey-Ayesavi]

Doesn't works.

[JesseRiemens]

Maybe something more like this? (I purposely left from/toJson out but I think you can figure that out)

import 'package:freezed_annotation/freezed_annotation.dart';

part 'freezed_test.freezed.dart';

abstract interface class MessageIf {
  String get message;
  String get author;

  Map<String, dynamic> toJson();

  factory MessageIf.fromJson(Map<String, dynamic> json) {
    if (json.containsKey('text')) {
      return TextMessage.fromJson(json);
    } else {
      return Message.fromJson(json);
    }
  }
}

@freezed
class Message with _$Message implements MessageIf {
  const factory Message({
    required String message,
    required String author,
  }) = _Message;

  factory Message.fromJson(Map<String, dynamic> json) => _$MessageFromJson(json);
}

@freezed
class TextMessage with _$TextMessage implements MessageIf {
  const factory TextMessage(
      {required String message,
      required String author,
      required String text}) = _TextMessage;

  factory TextMessage.fromJson(Map<String, dynamic> json) => _$TextMessageFromJson(json);
}

[Yogesh-Dubey-Ayesavi]

Well this approach works, But i need to type cast every message in toJson and then return it's respective toJson call, I could not write toJson in abstract and override it.

[JesseRiemens]

I think this implementation will cause freezed objects to be generated that do satisfy the abstract toJson as contracted by the interface.