Extracting value from object after comparing arrays IDs, Flutter - flutter

Question

I have 2 things I want to compare and return a list of Strings for each of the matching Ids with the corresponding names. Example: I have a list of "genre_ids": [16, 878, 28] from a movie, and from another API I get a list of objects with id and name of the genres, { "id": 878, "name": "Science Fiction" }. Now I want to compare the list of genre_ids with the list of objects with ids and names and return a List of names with all the matching Ids. How do I do that? I tried using the .where() option but failed miserably.
JSON from genre list:
{
"genres": [
{
"id": 28,
"name": "Action"
},
{
"id": 12,
"name": "Adventure"
},
{
"id": 16,
"name": "Animation"
},
{
"id": 35,
"name": "Comedy"
},
{
"id": 10749,
"name": "Romance"
},
{
"id": 878,
"name": "Science Fiction"
},
]
}
JSON from movie list:
"results": [
{
"adult": false,
"genre_ids": [
16,
878,
28
],
"id": 610150,
"release_date": "2022-06-11",
"title": "Dragon Ball Super: Super Hero",
"vote_average": 7.5,
"vote_count": 126
},
]
Both models from the APIs:
class Movies {
int? id;
String? title;
String? overview;
List<dynamic>? genreIds;
dynamic voteAverage;
String? posterPath;
Movies({
this.id,
this.title,
this.overview,
this.genreIds,
this.voteAverage,
this.posterPath,
});
Movies.fromJson(Map<String, dynamic> json) {
id = json['id'];
title = json['title'];
overview = json['overview'];
genreIds = json['genre_ids'].toList();
voteAverage = json['vote_average'];
posterPath = json['poster_path'];
}
Map<String, dynamic> toJson() {
final Map<String, dynamic> data = Map<String, dynamic>();
data['id'] = id;
data['title'] = title;
data['overview'] = overview;
data['vote_average'] = voteAverage;
data['genre_ids'] = genreIds;
data['poster_path'] = posterPath;
return data;
}
}
class Genres {
int? id;
String? name;
Genres({
this.id,
this.name,
});
Genres.fromJson(Map<String, dynamic> json) {
id = json['id'];
name = json['name'] as String;
}
Map<String, dynamic> toJson() {
final Map<String, dynamic> data = Map<String, dynamic>();
data['id'] = id;
data['name'] = name;
return data;
}
}
API calls:
Future<List<Movies?>> getAllMovies() async {
Response response = await Dio().get(Contants().moviesUrl);
return (response.data['results'] as List).map((movies) {
return Movies.fromJson(genres);
}).toList();
}
Future<List<Genres?>> getAllGenres() async {
Response response = await Dio().get(Contants().genresUrl);
return (response.data['genres'] as List).map((genres) {
return Genres.fromJson(genres);
}).toList();
}
Future builder:
FutureBuilder(
future: Future.wait([
RepositoryFromAPItoDB().gettAllMovies(),
RepositoryFromAPItoDB().getAllGenres()
]),
builder:
(BuildContext context, AsyncSnapshot<List<dynamic>?> snapshot) {
if (!snapshot.hasData) {
return const Center(
child: CircularProgressIndicator(),
);
} else {
return ListView.builder(
itemCount: snapshot.data?[0].length,
itemBuilder: (BuildContext context, int index) {
return MoviesListTile(
title: snapshot.data?[0][index].title,
voteAverage: snapshot.data?[0][index].voteAverage,
description: snapshot.data?[0][index].overview,
posterPath: snapshot.data?[0][index].posterPath,
genreIds: snapshot.data?[0][index].genreIds,
genres: ['drama', 'somehting'],
);
},
);
}
},
),
Requested output of names from the list:
Widget getTextWidgets(List<String?> strings) {
return Row(
children: strings
.map((item) => Container(
child: Text(
item!,
),
),
),
)
.toList());
}
Any form of help is appreciated.

Answer 1

Is this what you wanted?
void main() {
Map<String, dynamic> genres = {
"genres": [
{"id": 28, "name": "Action"},
{"id": 12, "name": "Adventure"},
{"id": 16, "name": "Animation"},
{"id": 35, "name": "Comedy"},
{"id": 10749, "name": "Romance"},
{"id": 878, "name": "Science Fiction"},
]
};
Map<String, dynamic> movie = {
"adult": false,
"genre_ids": [16, 878, 28],
"id": 610150,
"release_date": "2022-06-11",
"title": "Dragon Ball Super: Super Hero",
"vote_average": 7.5,
"vote_count": 126
};
print(getGenres(movie, genres["genres"]));
}
List getGenres(Map movie, List genres) {
final Set movieGenreIds = Set.from(movie["genre_ids"]);
return genres
.where((g) => movieGenreIds.contains(g["id"]))
.map((g) => g["name"])
.toList();
}
The output:
[Action, Animation, Science Fiction]
Edit, using the models you provided.
List getGenres(Movie movie, List<Genre> genres) {
final Set movieGenreIds = Set.from(movie.genreIds);
return genres
.where((g) => movieGenreIds.contains(g.id))
.map((g) => g.name)
.toList();
}