StreamBuilder not updating after an item is removed Flutter - sqlite

Question

I am new to Flutter and this is my first time asking a question on Stackoverflow. I apologize for any misunderstanding. I will try my best to make it clear.
I am using sqflite for storing user's favorites and populating a list from the DB on a page, named Favorites screen. This Favorites page is one of the items on my bottom navbar.
My issue is that when I tap on an item from the favorites list which takes me to a screen where I can unfavorite that item. I double-checked that it is really removed from the DB by logging the rows count. But when I go back to the Favorites page, that item is still on the list. If I go to one of the pages from the bottom navbar and go back to the Favorites screen, the item isn't there. I understand that the page is being rebuilt again this time but my intention was the Stream will constantly listen for a change.
I have also implemented a slide to dismiss feature on the fav screen, which works as intended. But I am using the same logic on both.
StreamBuilder code in Favorite screen
StreamBuilder<List<WeekMezmurList>>(
stream: favBloc.favStream,
builder: (context, AsyncSnapshot<List<WeekMezmurList>> snapshot) {
if (snapshot.connectionState == ConnectionState.waiting) {
return Center(
child: Text(
"Loading Favorites...",
style: TextStyle(fontSize: 20),
),
);
} else if (snapshot.data == null) {
return Center(
child: Text(
"No Favorites yet!",
style: TextStyle(
fontSize: 20,
fontWeight: FontWeight.bold,
),
),
);
} else {
return ListView.builder(
physics: BouncingScrollPhysics(),
padding: const EdgeInsets.fromLTRB(5.0, 10.0, 5.0, 10.0),
itemCount: snapshot.data.length,
itemBuilder: (BuildContext context, int index) {
return new GestureDetector(
onTap: () =>
Navigator.push(
context,
MaterialPageRoute(
builder: (context) =>
AudioPlayerScreen(
mezmurName: snapshot.data[index].mezmurName,
),
),
),
child: Slidable(
key: new Key(snapshot.data[index].mezmurName),
actionPane: SlidableDrawerActionPane(),
actionExtentRatio: 0.25,
// closes other active slidable if there is any
controller: slidableController,
secondaryActions: <Widget>[
IconSlideAction(
caption: 'Share',
color: Colors.indigo,
icon: Icons.share,
onTap: () =>
_share(snapshot
.data[index]),
),
IconSlideAction(
caption: 'Delete',
color: Colors.red,
icon: Icons.delete,
onTap: () =>
_swipeDelete(
context, snapshot.data[index].mezmurName),
),
],
child: Card(
color: Colors.white,
child: Padding(
padding: EdgeInsets.symmetric(
vertical: 15.0,
horizontal: 10.0,
),
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: <Widget>[
Row(
children: <Widget>[
_misbakChapter(
snapshot.data[index].misbakChapters),
SizedBox(width: 15),
_displayFavoritesMisbakLines(
snapshot.data[index], index),
],
)
],
),
),
),
),
);
},
);
}
},
);
slide to delete code in Favorites screen
// deletes the specific favorite from the sqflite db
Future<void> _swipeDelete(BuildContext context, String mezmurName) async {
try {
favBloc.delete(mezmurName);
} catch (e) {
CupertinoAlertDialog(
content: Text("Something went wrong. Please try again."),
actions: <Widget>[
CupertinoDialogAction(
child: Text(
"Ok",
),
onPressed: () => Navigator.of(context).pop(),
),
],
);
}
}
I have the same logic in the second screen, the screen I get when I tap on one of the items from the Fav list.
favBloc.delete(widget.mezmurName);
BLoC code, I got the concepts from this Medium article
class FavoritesBloc{
FavoritesBloc(){
getFavorites();
}
final databaseHelper = DatabaseHelper.instance;
// broadcast makes it to start listening to events
final _controller = StreamController<List<WeekMezmurList>>.broadcast();
get favStream => _controller.stream;
void dispose() {
_controller.close();
}
getFavorites () async{
_controller.sink.add(await databaseHelper.getFavorites());
}
insert(WeekMezmurList fav){
databaseHelper.insertToDb(fav);
getFavorites();
}
delete(String mezmurName){
databaseHelper.delete(mezmurName: mezmurName);
getFavorites();
}
}
Delete method in the DB class
// deleting a value from the db
delete({String mezmurName}) async {
var dbClient = await getDb;
try {
await dbClient
.delete(TABLE, where: '$MEZMUR_NAME = ?', whereArgs: [mezmurName]);
} catch (e) {
}
}
I have tried to research this issue but all I have found were for remote databases.
Just to make it more clear, I took a screen record.
Thank you in advance!

Answer 1

The reason why StreamBuilder on the first screen doesn't update with the changes made is because it uses a different instance of FavoritesBloc(). If you'd like for the bloc to be globally accessible with a single instance, you can declare it as
final favBloc = FavoritesBloc();
Otherwise, you can follow what has been suggested in the comments and pass FavoritesBloc as an argument between screens.