README-EN.md

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json_model

Generating Dart model class from Json files with one command.

Installing

dev_dependencies:
  json_model: ^1.0.0
  json_serializable: ^5.0.0

Getting Started

1. Create a "jsons" directory in the root of your project;
2. Create a Json file under "jsons" dir ;
3. Run flutter packages pub run json_model (in Flutter) or pub run json_model (in Dart VM)

Examples

File: jsons/user.json

{
  "name":"wendux",
  "father":"$user", //Other class model , use '$'
  "friends":"$[]user", // Array  
  "keywords":"$[]String", // Array
  "age?":20
}

Run pub run json_model, then you'll see the generated json file under lib/models/ dir:

import 'package:json_annotation/json_annotation.dart';

part 'user.g.dart';

@JsonSerializable()
class User {
  User();

  late String name;
  late User father;
  late List<User> friends;
  late List<String> keywords;
  num? age;
  
  factory User.fromJson(Map<String,dynamic> json) => _$UserFromJson(json);
  Map<String, dynamic> toJson() => _$UserToJson(this);
}

@JsonKey

You can also use “@JsonKey” annotation from json_annotation package.

{
  "@JsonKey(name: '+1') int?": "loved", //将“+1”映射为“loved”
  "name":"wendux",
  "age?":20
}

The generated class is:

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

@JsonSerializable()
class User {
  User();
  @JsonKey(name: '+1') int? loved;
  late String name;
  num? age;
    
  factory User.fromJson(Map<String,dynamic> json) => _$UserFromJson(json);
  Map<String, dynamic> toJson() => _$UserToJson(this);
}

Test:

import 'models/index.dart';

void main() {
  var u = User.fromJson({"name": "Jack", "age": 16, "+1": 20});
  print(u.loved); // 20
}

$meta

"@meta": {
  "import": [  //import file for model class
    "test_dir/profile.dart"
  ],
  "comments": { // comments for fields
    "name": "nick name"
  },
  "nullable": true, // fields are nullable?
  "ignore": false // Wether skip this json file when generating dart model class.
}

user.json

{
  "@meta": {
    "import": [
      "test_dir/profile.dart"
    ],
    "comments": {
      "name": "名字"
    },
    "nullable": true
  },
  "@JsonKey(ignore: true) Profile?": "profile",
  "@JsonKey(name: '+1') int?": "loved",
  "name": "wendux",
  "father": "$user",
  "friends": "$[]user",
  "keywords": "$[]String",
  "age?": 20
}

The generated class:

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

@JsonSerializable()
class User {
  User();

  @JsonKey(ignore: true) Profile? profile;
  @JsonKey(name: '+1') int? loved;
  //nick name
  String? name;
  User? father;
  List<User>? friends;
  List<String>? keywords;
  num? age;
  
  factory User.fromJson(Map<String,dynamic> json) => _$UserFromJson(json);
  Map<String, dynamic> toJson() => _$UserToJson(this);
}

For completed examples see here .

Command arguments

The default json source file directory is project_root/jsons; you can custom the src file directory by src argument, for example:

pub run json_model src=json_files 

You can also custom the dist directory by dist argument:

pub run json_model src=json_files  dist=data # will save in lib/data dir

The dist root is lib

You can spcify the --nullable flag to make fields of dart model class defauts to nullable.

pub run json_model --nullable

Run by code

If you want to run json_model by code instead command line, you can:

import 'package:json_model/json_model.dart';
void main() {
  run(['src=jsons']);  //run
}