NoSuchMethodError: 'cast' with dart language - flutter

Question

i'm following flutter offical docs to parse JSON in the background with the rest api from themoviedb. I get this following error when trying to show the list of movies
the api link : https://api.themoviedb.org/3/trending/movie/week?api_key=$apiKey
json data
app.dart'
simplify main.dart and isolate parsing using compute
import 'dart:convert';
import 'package:flutter/material.dart';
import 'models/movie_response.dart';
import 'package:auth_request/api_key.dart';
import 'package:flutter/foundation.dart';
import 'package:http/http.dart' as http;
Future<List<Movie>> fetchMovies(http.Client client) async {
final response = await client
.get(Uri.parse('https://api.themoviedb.org/3/trending/movie/week?api_key=$apiKey'));
// Use the compute funtion to run fetchMovies in a separate isolate
return compute(parseMovies, response.body);
}
// A function that converts a response body into a List<Movie>.
List<Movie> parseMovies(String responseBody) {
final parsed = jsonDecode(responseBody).cast<Map<String, dynamic>>();
return parsed.map<Movie>((json) => Movie.fromJson(json)).toList();
}
class MovieApp extends StatefulWidget {
const MovieApp({super.key});
#override
MovieAppState createState() => MovieAppState();
}
class MovieAppState extends State<MovieApp> {
late Future<Movie> futureAlbum;
#override
void initState() {
super.initState();
}
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'MovieDB List',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: Scaffold(
appBar: AppBar(
title: const Text('MovieDB List'),
),
body: Center(
child: FutureBuilder<List<Movie>>(
future: fetchMovies(http.Client()),
builder: (context, snapshot) {
if (snapshot.hasError) {
return Text('${snapshot.error}');
} else if (snapshot.hasData) {
return MoviesList(movies: snapshot.data!);
} else {
return const Center(
child: CircularProgressIndicator(),
);
}
},
),
),
),
);
}
}
//
class MoviesList extends StatelessWidget {
const MoviesList({super.key, required this.movies});
final List<Movie> movies;
#override
Widget build(BuildContext context) {
return GridView.builder(
gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
crossAxisCount: 2,
),
itemBuilder: (context, index) {
return Image.network(movies[index].original_title);
},
);
}
}
movie.dart
Parse and convert the JSON into a list of movies with the help of map and factory
class Movie {
final String original_title;
final String overview;
final String poster_path;
final String release_date;
const Movie({
required this.original_title,
required this.overview,
required this.poster_path,
required this.release_date,
});
factory Movie.fromJson(Map<String, dynamic> json) {
return Movie(
original_title: json['original_title'],
overview: json['overview'],
poster_path: json['poster_path'],
release_date: json['release_date'],
);
}
}

Answer 1

change this:
final parsed = jsonDecode(responseBody).cast<Map<String, dynamic>>();
to
final parsed = jsonDecode(responseBody)['results'];