Flutter 'List<dynamic>' is not a subtype of type 'Map<String, dynamic>'

Question

I'm currently building a Flutter app which fetches data from an Api, but when I run the application I'm getting the error Flutter 'List' is not a subtype of type 'Map<String, dynamic>'.Here is my code

    class NewsData with ChangeNotifier 
{

  Map<String,dynamic> _map = {};
  bool _error = false;
  String _errorMessage = '';

  Map<String,dynamic> get map => _map;
  bool get error => _error;
  String get errorMessage => _errorMessage;

  Future<void> get fetchdata async {
    final response = await get(Uri.parse('https://script.google.com/macros/s/AKfycbz3ZmaMiTgR-y70MEE1v9VPz2QtmNzwnnnnnnn/exec'),);
   if (response.statusCode == 200)
    {
    try
     {
       _map = jsonDecode(response.body);
       _error = false;
     }
     catch(e) {
       _error = true;
       _errorMessage = e.toString();
       _map = {};
     }
   }
   else
   {
    _error = true; 
    _errorMessage = 'Error :it could be your internet connection ';
       _map = {};
   }
    notifyListeners();
  }
  void initialValues()
  {
    _map = {};
    _error = false;
    _errorMessage = '';
     notifyListeners();
  }
}


stories.dart

class Storiespage extends StatelessWidget {
  const Storiespage({ Key? key }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    context.read<NewsData>().fetchdata;
    return Scaffold(
     appBar: AppBar(
       actions: [
         IconButton(
           icon: Icon(Icons.refresh),
           onPressed:() {
             context.read<NewsData>().initialValues();
              context.read<NewsData>().fetchdata;
           },
         )
       ],
       title: Text('ggg'),
     ),
     body: RefreshIndicator(
       onRefresh: () async {
        await context.read<NewsData>().fetchdata;
       },
       child: Center(
        child: Consumer<NewsData>(
        builder: (context, value, child) {
          return value.map.length == 0 && !value.error 
          ? CircularProgressIndicator() 
          : value.error ? Text('oops,something went wrong ${value.errorMessage}'
          ,textAlign: TextAlign.center,) : 
          ListView.builder(
            itemCount: value.map['feedback'].length,
            itemBuilder: (context,index) {
            
            
            return Newscard(map: value.map['feedback'][index]);
          },
          );
        },
        ),
       ),
     ), 
    );
  }
}

class Newscard extends StatelessWidget {
  const Newscard({ Key? key,required this.map }) : super(key: key);
final Map<String,dynamic> map;
  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.all(8.0),
      child: Card(
        elevation:10 ,
        child: Padding(
          padding: const EdgeInsets.all(8.0),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Image.network('${map['image']}'),
            SizedBox(
              height: 10,
            ),
            Text('${map['heading']}'
            ),
           SizedBox(
              height: 10,
            ),
              Text('${map['story']}'
            ),
            ],
            
          ),
        ),
      ),
    );
  }
}

and json file [ {"heading":"admire","story":2021,"date":" WORLD ","image":"01/A0000/06"},{"heading":"admire","story":2021,"date":" WORLD ","image":"01/A0000/06"},{"heading":"heading","story":"story","date":"date","image":"image"}]

quoci · Accepted Answer · 2022-02-20 09:31:11Z

10

The error occurs because your API returns a List as you can see in your json file. After you use jsonDecode your type of the decoding is List<dynamic>. To fix your issue you have to change the type of _map to List<dynamic>. If you want to have the type List<Map<String, dynamic>> you can do the following.

List<Map<String, dynamic>> map = [];
...
_map = List<Map<String, dynamic>>.from(jsonDecode(response.body));

answered Feb 20, 2022 at 9:31

quoci

3,6071 gold badge13 silver badges31 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

CPlus · Accepted Answer · 2024-03-13 06:21:33Z

0

Just change map<String,dynamic> to List<dynamic> and you are good to go.

edited Mar 13, 2024 at 6:21

CPlus

5,12048 gold badges33 silver badges77 bronze badges

answered Mar 8, 2024 at 17:09

Adarsh Srivastava

11 bronze badge

1 Comment

Community Over a year ago

Your answer could be improved with additional supporting information. Please edit to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers in the help center.

Marcel Hofgesang · Accepted Answer · 2024-03-20 14:07:13Z

0

Your _map Variable is of type Map<String, dynamic>, which means it can be used to store a single map element, consisting of key value pairs.

The result of jsonDecode of the response is of type List<Map>. So change the declaration of _map to

List<Map<String,dynamic>> _map;

OR simply

List _map;

OR

var _map;

edited Mar 20, 2024 at 14:07

Marcel Hofgesang

1,1101 gold badge20 silver badges39 bronze badges

answered Feb 20, 2022 at 9:31

AMALRAJ P

11 bronze badge

Collectives™ on Stack Overflow

Flutter 'List<dynamic>' is not a subtype of type 'Map<String, dynamic>'

3 Answers 3

Comments

1 Comment

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related