How to parse a json with dynamic array'keys?

Question

I need to parse a json with dynamic arrays keys like this :

[{ key1:{ title: ....., img: ....., }, key2:{ title: ....., img: ....., }, }]

I know how to parse a json like this:

[ {title: .....,nbLike: ...}, {title: ...., nbLike: ...} ]

but i didn't find anything about parsing json with a dynamic key like this.

I tried this but it doesnt work.

class Event {
  final String title;
  final int nbLike;

 Event({this.title, this.nbLike});

  factory Event.fromJson(Map<String, dynamic> json) {
    return Event(
      title: json['title'] as String,
      nbLike: json['nbLike'] as int,
    );
  }
}




Future<List<Event>> fetchPosts(http.Client client) async {
  final response = '[{"2019-01-15":{"title":"Hey","nbLike":1}, "2019-01- 
 16":{"title":"Hey2","nbLike":2}}]';


  return compute(parsePosts, response);
}

List<Event> parsePosts(String responseBody) {
   List<Event> events = new List<Event>();
    List jsonParsed = json.decode(responseBody.toString());
    for (int i = 0; i < jsonParsed.length; i++) {
      print('jsonParsed1 ${jsonParsed.length}');
      print('jsonParsed ${jsonParsed[i]}');
      events.add(new Event.fromJson(jsonParsed[i]));
    }
    return events;
}

I receive json from API with a key and i want to transform it to this

[{title: .....,nbLike: ...},{title: ...., nbLike: ...}]

to create a 'Event' list and display it in a card list.

Pierre Le Brun · Accepted Answer · 2019-01-16 13:33:02Z

It is the complete code if someone need it, Thanks KURRU HEM.

    Map<String, dynamic> jsonParsed = {"2019-01-15":{"title":"Hey","nbLike":1}, "2019-01-16":{"title":"Hey2","nbLike":2}};
    print(jsonParsed);
 List<Event> _events = [];
List _dates = [];
jsonParsed.keys.forEach((String key){
   _dates.add(key);
});
  print(_dates);
for(int i=0; i<_dates.length; i++){
  print(jsonParsed[_dates[i]]['title']);
  print(jsonParsed[_dates[i]]['nbLike']);
   final Event event = Event(
      title: jsonParsed[_dates[i]]['title'],
      nbLike: jsonParsed[_dates[i]]['nbLike'],
);
    _events.add(event);
}
print('EVENTS --------------> $_events');


class Event {
  final String title;
  final int nbLike;

 Event({this.title, this.nbLike});

  factory Event.fromJson(Map<String, dynamic> json) {
    return Event(
      title: json['title'] as String,
      nbLike: json['nbLike'] as int,
    );
  }
}

KURRU HEM · Accepted Answer · 2019-01-16 10:10:53Z

0

Try this.

List _events = [];
List _dates = [];
jsonParsed.keys.forEach((String key){
   _dates.add(key);
});
for(int i=0; i<_dates.length; i++){
  jsonParsed[_date[i]].forEach((event){
   final Event event = Event(
      title: jsonParsed['title'],
      nbLike: jsonParsed['nbLike'],

    );
    _events.add(event);
  });
}

answered Jan 16, 2019 at 10:10

KURRU HEM

1,9733 gold badges17 silver badges22 bronze badges

4 Comments

Pierre Le Brun Over a year ago

i have this error for jsonParsed.keys : [dart] The getter 'keys' isn't defined for the class 'List'. [undefined_getter]

KURRU HEM Over a year ago

Change the paredJson to type Map

Pierre Le Brun Over a year ago

I change it but foreach can't accept key as string, so i change to dynamic. The code dont show errors but flutter give me this error : type 'List<dynamic>' is not a subtype of type 'Map<dynamic, dynamic>', sorry iam new with flutter

KURRU HEM Over a year ago

Map<String, dynamic> jsonParsed = {}; Try this. I worked similar type of json format. I first stored the keys in list and later extracted the details using the keys stored in the list

Collectives™ on Stack Overflow

How to parse a json with dynamic array'keys?

2 Answers 2

Comments

4 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

4 Comments

Your Answer

Sign up or log in

Post as a guest

Related