REST API NoSuchMethodError-CodePudding

I have problem with read my own custom API. When I try to read it a have an error :

" NoSuchMethodError: The method'[]' was called on null. Receiver: null Tried calling : "

My DataSource :

class MotivationQuotesRemoteDioDataSources {
Future<List<Map<String, dynamic>>?> getQuotesRespondeData()          async {
final response = await Dio().get<List<dynamic>>(
    'https://my-json-server.typicode.com/jargawl/json/quotes');
final listDynamic = response.data;
if (listDynamic == null) {
  return null;
}
return listDynamic.map((e) => e as Map<String, dynamic>).toList();

} }

My Repositories : 
class MotivationQuotesRepositories {
MotivationQuotesRepositories(
  {required this.motivationQuotesRemoteDioDataSources});
final MotivationQuotesRemoteDioDataSources
  motivationQuotesRemoteDioDataSources;

   Future<List<QuotesModel>> getQuotesModel() async {
final json =
    await     motivationQuotesRemoteDioDataSources.getQuotesRespondeData();
if (json == null) {
  return [];
}

return json.map((item) => QuotesModel.fromJson(item)).toList();

} }

My model:
class QuotesModel {
QuotesModel(
this.text,
this.author,
);

final String text;
final String author;

 QuotesModel.fromJson(Map<String, dynamic> json)
  : text = json['quotes']['text'],
    author = json['quotes']['author'];
 }

I try to use there :

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

   @override
   Widget build(BuildContext context) {
   return SliverToBoxAdapter(
   child: BlocProvider(
    create: (context) => QoutesCardCubit(
      motivationQuotesRepositories:   MotivationQuotesRepositories(
        motivationQuotesRemoteDioDataSources:
            MotivationQuotesRemoteDioDataSources(),
      ),
    )..start(),
    child: BlocBuilder<QoutesCardCubit, QoutesCardState>(
      builder: (context, state) {
        switch (state.status) {
          case Status.initial:
            return const Center(
              child: Text('Initial state'),
            );
          case Status.loading:
            return const Center(
              child: CircularProgressIndicator(),
            );
          case Status.success:
            return ListView(
              scrollDirection: Axis.horizontal,
              children: [
                for (final quotesModel in state.results)
                  QoutesCard(quotesModel: quotesModel)
              ],
            );
          case Status.error:
            return Center(
              child: Text(state.errorMessage ?? 'Unknown  error'),
            );
        }
        },
        ),
        ),
        );
        }
        }

Can someone tell me why it don't work ? It should be a simple ListView (with Containers) with same motivation quotes.

CodePudding user response：

Here response is a string. Json decode it to map it

final listDynamic = json.decode(response.data);

Plus dont define the type here

final response = await Dio().get(
    'https://my-json-server.typicode.com/jargawl/json/quotes');

CodePudding user response：

There are no 'quotes' in data, so the model should look like this:

class QuotesModel {
  QuotesModel(
    this.text,
    this.author,
  );

  final String text;
  final String author;

  QuotesModel.fromJson(Map<String, dynamic> json): 
    text = json['text'], 
    author = json['author'];
}