flutter dart JsonSerializable with inherited class

Question

I have the following two classes where one is extending from the other like this :

@JsonSerializable(nullable: true)
class Response {
  final String responseCode;
  final String responseMessage;
  final String errorLog;
  Response({this.errorLog, this.responseCode, this.responseMessage});
  factory Response.fromJson(Map<String, dynamic> json) =>
      _$ResponseFromJson(json);
}

.........................................................

 @JsonSerializable(nullable: false)
class Verify extends Response {
  Data data;
  Verify({
    this.data,
  });
  factory Verify.fromJson(Map<String, dynamic> json) => _$VerifyFromJson(json);
  Map<String, dynamic> toJson() => _$VerifyToJson(this);
}

and whenever I'm trying to read response class properties from Verify class, it's always null.

so please how to achieve this?

Solution 1

this one I have solved by passing the parameters to super in verify class constructor like this

@JsonSerializable()
class VerifyResponse extends Response {
  Data data;

  VerifyResponse({
    this.data,
    String responseCode,
    String responseMessage,
  }) : super(responseCode: responseCode, responseMessage: responseMessage);

  factory VerifyResponse.fromJson(Map<String, dynamic> json) =>
      _$VerifyResponseFromJson(json);

  Map<String, dynamic> toJson() => _$VerifyResponseToJson(this);
}

and for the response class it remains the same

@JsonSerializable()
class Response {
  final String responseCode;
  final String responseMessage;

  Response({this.responseCode, this.responseMessage});

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

it's a bit annoying but it's what it's.

Solution 2

You should remove 'final' keyword from Response Class

@JsonSerializable(nullable: true)
    class Response {
      String responseCode;
      String responseMessage;
      String errorLog;
      Response({this.errorLog, this.responseCode, this.responseMessage});
      factory Response.fromJson(Map<String, dynamic> json) =>
           _$ResponseFromJson(json);
}