Why is data not being refreshed in StreamBuilder? - api

Question

I am making a movie list application in Flutter and when I open the app I am displaying most-viewed movies list. When I click a button, I fetch new data and add it to the sink which is then sent to the StreamBuilder and should refresh the screen with new data.
But that doesn't happen. I cannot fathom why!
Here is my code for the Repository:
class MoviesRepository {
final _movieApiProvider = MovieApiProvider();
fetchAllMovies() async => _movieApiProvider.fetchMovieList();
fetchAllSimilarMovies(genreIdeas) async => await _movieApiProvider.fetchMoviesLikeThis(genreIdeas);
fetchTopRatedMovies() async => await _movieApiProvider.fetchTopRatedMovieList();
}
Here is my code for bloc:
class MoviesBloc {
final _moviesRepository = MoviesRepository();
final _moviesFetcher = BehaviorSubject<Result>();
Sink<Result> get allMovies => _fetcherController.sink;
final _fetcherController = StreamController<Result>();
Observable<Result> get newResults => _moviesFetcher.stream;
fetchAllMovies() async {
Result model = await _moviesRepository.fetchAllMovies();
allMovies.add(model);
}
fetchTopRatedMovies() async{
Result model = await _moviesRepository.fetchTopRatedMovies();
allMovies.add(model);
}
dispose() {
_moviesFetcher.close();
_fetcherController.close();
}
MoviesBloc() {
_fetcherController.stream.listen(_handle);
}
void _handle(Result event) {
_moviesFetcher.add(event);
}
}
final bloc = MoviesBloc();
UPDATE
And here is my code for the StreamBuilder:
class HomeScreenListState extends State<HomeScreenList> {
#override
void initState() {
super.initState();
print("init");
bloc.fetchAllMovies();
}
#override
void dispose() {
super.dispose();
bloc.dispose();
}
#override
Widget build(BuildContext context) {
return StreamBuilder<Result>(
builder: (context, snapshot) {
if (snapshot.hasData) {
print("new data is here");
return buildList(snapshot);
} else if (snapshot.hasError) {
return Text('Error!!');
}
return Center(
child: CircularProgressIndicator(),
);
},
stream: bloc.newResults,
);
}
}
And this is the button that triggers to get new data and add it to the sink:
child: RaisedButton(onPressed: () {
bloc.fetchTopRatedMovies();
},
This button fetches top-rated movies and add to the same sink. Now the StreamBuilder should pick up the new data as I think.
Where is the problem??

Answer 1

You can use Equatable alongside your BLoC implementation to manage state changes on your screen. Here's a guide that I suggest trying out.