Registering User using Flutter and PHP Laravel and saving User info with SharedPreferrence - flutter

Question

I am trying to save result from json to SharedPreferrence but i keep getting Unhandled Exception: type 'String' is not a subtype of type 'int' of 'index'
This is my Code
_register(BuildContext context, User user) async {
var _userService = UserService();
var registeredUser = await _userService.createUser(user);
var encodeFirst = json.encode(registeredUser.body);
var result = json.decode(encodeFirst);
if(result['result'] == true){
SharedPreferences _prefs = await SharedPreferences.getInstance();
_prefs.setInt("userId", result["user"]["id"]);
_prefs.setString("userName", result["user"]["name"]);
_prefs.setString("userEmail", result["user"]["email"]);
Navigator.push(
context, MaterialPageRoute(builder: (context) => CheckoutScreen(cartItems: this.widget.cartItems,)));
} else {
_showSnackMessage(Text('Failed to register the user!', style: TextStyle(color: Colors.red),));
}
}
this is my User, UserService and Repository file
class User{
int id;
String name;
String email;
String password;
toJson(){
return{
'id': id.toString(),
'name': name,
'email': email,
'password': password
};
}
}
class UserService {
Repository _repository;
UserService(){
_repository = Repository();
}
createUser(User user) async{
return await _repository.httpPost('register', user.toJson());
}
}
httpPost(String api, data) async {
return await http.post(_baseUrl + "/" + api, body: data);
}

Answer 1

var encodeFirst = json.encode(registeredUser.body); will call User toJson()
And in toJson() , you have set 'id': id.toString(),
when you do var result = json.decode(encodeFirst);
It's actually a string not int
Correct toJson() please see below
// To parse this JSON data, do
//
// final user = userFromJson(jsonString);
import 'dart:convert';
User userFromJson(String str) => User.fromJson(json.decode(str));
String userToJson(User data) => json.encode(data.toJson());
class User {
int id;
String name;
String email;
String password;
User({
this.id,
this.name,
this.email,
this.password,
});
factory User.fromJson(Map<String, dynamic> json) => User(
id: json["id"],
name: json["name"],
email: json["email"],
password: json["password"],
);
Map<String, dynamic> toJson() => {
"id": id,
"name": name,
"email": email,
"password": password,
};
}