Flutter Json Encode List

Issue

How to encode list to json?

This is my class for Json.

class Players{
  List<Player> players;

  Players({this.players});

  factory Players.fromJson(List<dynamic> parsedJson){

    List<Player> players = List<Player>();
    players = parsedJson.map((i)=>Player.fromJson(i)).toList();

    return Players(
      players: players,
    );
  }
}

class Player{
  final String name;
  final String imagePath;
  final int totalGames;
  final int points;

  Player({this.name,this.imagePath, this.totalGames, this.points});

  factory Player.fromJson(Map<String, dynamic> json){

    return Player(
      name: json['name'],
      imagePath: json['imagePath'],
      totalGames: json['totalGames'],
      points: json['points'],
    );
  }
}

I managed to decode with fromJson, the result is in List. Now that I have another player to add in json and want to encode the list to json, have no idea to do it. It result always failed.

var json = jsonDecode(data);
List<Player> players = Players.fromJson(json).players;
Player newPlayer = Player(name: _textEditing.text,imagePath: _imagePath,totalGames: 0,points: 0);
players.add(newPlayer);
String encode = jsonEncode(players.players);

What do I need to add on Players or Player?

Solution

Add toJson method to your Player class:

Map<String, dynamic> toJson(){
  return {
    "name": this.name,
    "imagePath": this.imagePath,
    "totalGames": this.totalGames,
    "points": this.points
  };
}

Then you can call jsonEncode on the list of players:

String encoded = jsonEncode(players) // this will automatically call toJson on each player

Answered By – Sami Kanafani

Answer Checked By – David Goodson (FlutterFixes Volunteer)