Dart convert array of json objects to list of objects

Question

I have array of country json objects like this

[{"id":4,"name":"Afghanistan","alpha2":"af","alpha3":"afg"},
        {"id":8,"name":"Albania","alpha2":"al","alpha3":"alb"},
        {"id":12,"name":"Algeria","alpha2":"dz","alpha3":"dza"},..

I have got them to a map like this

Map<String, dynamic> jsonMap;
jsonMap = json.decode(jsonString);

After this I have the data like this

[{id: 4, name: Afghanistan, alpha2: af, alpha3: afg}, {id: 8, name: Albania, alpha2: al, alpha3: alb}, ...

What i want to do is create a List of county objects from this

Country
{
int id;
String name;
String alpha2;
String alpha3;
}

Can anyone explain how to do this conversion ?

Darsh Shah · Accepted Answer · 2020-10-09 08:41:19Z

The best way to do it is to make a PODO out of this,

class Country {
  int id;
  String name;
  String alpha2;
  String alpha3;

  Country({this.id, this.name, this.alpha2, this.alpha3});

  Country.fromJson(Map<String, dynamic> json) {
    id = json['id'];
    name = json['name'];
    alpha2 = json['alpha2'];
    alpha3 = json['alpha3'];
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    data['id'] = this.id;
    data['name'] = this.name;
    data['alpha2'] = this.alpha2;
    data['alpha3'] = this.alpha3;
    return data;
  }
}

Now using this you can access the fromJson method and also use the toJson method.

Maz341 · Accepted Answer · 2020-10-09 05:41:48Z

0

I use this straight forward way:

List<TestModel> myTestModel;
var response = await http.get("myTestUrl");

myTestModel=(json.decode(response.body) as List).map((i) =>
              TestModel.fromJson(i)).toList();

The link can be really helpful: json_serializable

edited Oct 9, 2020 at 5:41

answered Oct 9, 2020 at 5:26

Maz341

2,52219 silver badges22 bronze badges

4 Comments

Janaka Over a year ago

can you explain TestModel.fromJson method?

Maz341 Over a year ago

fromJson is a Function of json_annotation which is used in decoding the assosiated JSON value to the annotated field.

Maz341 Over a year ago

and TestModel is the same class as your Country class which has fields

Maz341 Over a year ago

and if you want to learn more about how to parse complex json you can have a look at this article. :) medium.com/flutter-community/…

Collectives™ on Stack Overflow

Dart convert array of json objects to list of objects

2 Answers 2

Comments

4 Comments

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

4 Comments

Related