jsontodart

Demo : https://jsontodart.zariman.dev/

How to use

Method 1

1. Copy JSON
2. Open Command Pallete, and find JsonToDart: Convert JSON from Clipboard
3. Fill the box, select the option
4. Done

Method 2

1. Copy JSON
2. Right click on folder or dart file
3. Click Convert JSON from Clipboard Here
4. Fill the box, select the option
5. Done

More Configuration

To handle null value on generated model, you can define/change data type on pubspec.yaml

Sample

{
    "data": {
        "id": 2,
        "email": "janet.weaver@reqres.in",
        "first_name": "Janet",
        "last_name": "Weaver",
        "avatar": "https://reqres.in/img/faces/2-image.jpg"
    },
    "support": {
        "url": "https://reqres.in/#support-heading",
        "text": "To keep ReqRes free, contributions towards server costs are appreciated!"
    }
}

Output:

Legacy

config:

jsonToDart:
  engine: legacy
  outputFolder: lib/models #default: lib/
  typeChecking: true  #default: undefined (Select from picker)
  nullValueDataType: String #default: dynamic
  nullSafety: false #default: false
  copyWithMethod: true #default: false
  fromListMethod: true #default: false
  mergeArrayApproach: false #default: true
  
   #default: false, 
   #if true, value = (json[key] as num).toInt() or value = (_data[key] as num).toDouble()
   #if false, value = json[key]
   #if "ask", selection popup will apear before parse json
  checkNumberAsNum: true # true, false, "ask"

Object:

class User {
  Data data;
  Support support;

  User({this.data, this.support});

  User.fromJson(Map<String, dynamic> json) {
    if(json["data"] is Map) {
      data = json["data"] == null ? null : Data.fromJson(json["data"]);
    }
    if(json["support"] is Map) {
      support = json["support"] == null ? null : Support.fromJson(json["support"]);
    }
  }

  static List<User> fromList(List<Map<String, dynamic>> list) {
    return list.map(User.fromJson).toList();
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> _data = <String, dynamic>{};
    if(data != null) {
      _data["data"] = data.toJson();
    }
    if(support != null) {
      _data["support"] = support.toJson();
    }
    return _data;
  }

  User copyWith({
    Data data,
    Support support,
  }) => User(
    data: data ?? this.data,
    support: support ?? this.support,
  );
}

class Support {
  String url;
  String text;

  Support({this.url, this.text});

  Support.fromJson(Map<String, dynamic> json) {
    if(json["url"] is String) {
      url = json["url"];
    }
    if(json["text"] is String) {
      text = json["text"];
    }
  }

  static List<Support> fromList(List<Map<String, dynamic>> list) {
    return list.map(Support.fromJson).toList();
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> _data = <String, dynamic>{};
    _data["url"] = url;
    _data["text"] = text;
    return _data;
  }

  Support copyWith({
    String url,
    String text,
  }) => Support(
    url: url ?? this.url,
    text: text ?? this.text,
  );
}

class Data {
  int id;
  String email;
  String firstName;
  String lastName;
  String avatar;

  Data({this.id, this.email, this.firstName, this.lastName, this.avatar});

  Data.fromJson(Map<String, dynamic> json) {
    if(json["id"] is num) {
      id = (json["id"] as num).toInt();
    }
    if(json["email"] is String) {
      email = json["email"];
    }
    if(json["first_name"] is String) {
      firstName = json["first_name"];
    }
    if(json["last_name"] is String) {
      lastName = json["last_name"];
    }
    if(json["avatar"] is String) {
      avatar = json["avatar"];
    }
  }

  static List<Data> fromList(List<Map<String, dynamic>> list) {
    return list.map(Data.fromJson).toList();
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> _data = <String, dynamic>{};
    _data["id"] = id;
    _data["email"] = email;
    _data["first_name"] = firstName;
    _data["last_name"] = lastName;
    _data["avatar"] = avatar;
    return _data;
  }

  Data copyWith({
    int id,
    String email,
    String firstName,
    String lastName,
    String avatar,
  }) => Data(
    id: id ?? this.id,
    email: email ?? this.email,
    firstName: firstName ?? this.firstName,
    lastName: lastName ?? this.lastName,
    avatar: avatar ?? this.avatar,
  );
}

---

Json_serializable

config:

jsonToDart:
  engine: json_serializable
  outputFolder: lib/models #default: lib/
  typeChecking: true  #default: undefined (Select from picker)
  nullValueDataType: String #default: dynamic
  nullSafety: false #default: false
  copyWithMethod: true #default: false
  fromListMethod: true #default: false
  mergeArrayApproach: false #default: true
  package: package:json_annotation/json_annotation.dart
  
   #default: false, 
   #if true, value = (json[key] as num).toInt() or value = (_data[key] as num).toDouble()
   #if false, value = json[key]
   #if "ask", selection popup will apear before parse json
  checkNumberAsNum: true # true, false, "ask"

Object:

import 'package:json_annotation/json_annotation.dart';
part 'user.g.dart';

@JsonSerializable()
class User {
  @JsonKey(name: 'data')
  Data data;
  @JsonKey(name: 'support')
  Support support;

  User({this.data, this.support});

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

  static List<User> fromList(List<Map<String, dynamic>> list) {
    return list.map(User.fromJson).toList();
  }

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

  User copyWith({
    Data data,
    Support support,
  }) => User(
    data: data ?? this.data,
    support: support ?? this.support,
  );
}

@JsonSerializable()
class Support {
  @JsonKey(name: 'url')
  String url;
  @JsonKey(name: 'text')
  String text;

  Support({this.url, this.text});

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

  static List<Support> fromList(List<Map<String, dynamic>> list) {
    return list.map(Support.fromJson).toList();
  }

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

  Support copyWith({
    String url,
    String text,
  }) => Support(
    url: url ?? this.url,
    text: text ?? this.text,
  );
}

@JsonSerializable()
class Data {
  @JsonKey(name: 'id')
  int id;
  @JsonKey(name: 'email')
  String email;
  @JsonKey(name: 'first_name')
  String firstName;
  @JsonKey(name: 'last_name')
  String lastName;
  @JsonKey(name: 'avatar')
  String avatar;

  Data({this.id, this.email, this.firstName, this.lastName, this.avatar});

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

  static List<Data> fromList(List<Map<String, dynamic>> list) {
    return list.map(Data.fromJson).toList();
  }

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

  Data copyWith({
    int id,
    String email,
    String firstName,
    String lastName,
    String avatar,
  }) => Data(
    id: id ?? this.id,
    email: email ?? this.email,
    firstName: firstName ?? this.firstName,
    lastName: lastName ?? this.lastName,
    avatar: avatar ?? this.avatar,
  );
}

Customize (pubspec.yaml)

jsonToDart:
  engine: json_serializable # json_serializable or legacy
  outputFolder: lib/models #default: lib/
  typeChecking: true  #default: undefined (Select from picker)
  nullValueDataType: String #default: dynamic
  nullSafety: false #default: true
  copyWithMethod: true #default: false
  fromListMethod: true #default: false
  mergeArrayApproach: false #default: true
  package: package:freezed_annotation/freezed_annotation.dart # default: package:json_annotation/json_annotation.dart
  
   #default: false, 
   #if true, value = (json[key] as num).toInt() or value = (_data[key] as num).toDouble()
   #if false, value = json[key]
   #if "ask", selection popup will apear before parse json
  checkNumberAsNum: true # true, false, "ask"