Flutter / Equatable / Entity + Model Sample

equatable_entity.dart

import 'package:equatable/equatable.dart';
import 'package:meta/meta.dart';
class UserEntity extends Equatable {
  final String id;
  final String username;
  final String password;
  final List<LinkEntity> links;
  
  UserEntity({
    @required this.id,
    @required this.username,
    @required this.password,
    @required this.links,
  });

  @override
  List<Object> get props => [id, username, password, links];
}

equatable_model.dart

import 'package:equatable_entity.dart';
import 'package:meta/meta.dart';
import 'link_model.dart';

class UserModel extends UserEntity {
  ArtistModel({
    String id,
    @required String username,
    @required String password,
    @required List<LinkModel> links,
  }) : super(
    id: id,
    username: username,
    password: password,
    links: links,
  );

  factory UserModel.fromJson(Map<String, dynamic> json) {
    return UserModel(
      id: json["id"],
      username: json["username"] ?? "",
      password: json["password"] ?? "",
      links: json["links"] == null ? [] : (json["links"] as List).map((e) => LinkModel.fromJson(e)).toList(),
    );
  }

  factory UserModel.fromEntity(UserEntity entity) {
    return UserModel(
      id: entity.id,
      username: entity.username,
      password: entity.password,
      links: entity.links,
    );
  }

  Map<String, dynamic> toJson() {
    return {
      "id": id,
      "username": username,
      "password": password,
      "links": links == null ? [] : links.map((e) => LinkModel.fromEntity(e).toJson()).toList(),
    };
  }

  UserEntity toEntity() {
    return UserEntity(
      id: id,
      username: username,
      password: password,
      links: links,
    );
  }
}

Very ceratin.

But toJson doesn't print a right json object, I mean, the username value is not printed with double quotes.