英文:
Flutter: Disposing of resources in @riverpod generated provider
问题
我在我的Flutter应用中使用riverpod_generator生成一个供应程序(provider)，用于控制器(controller)。该控制器实际上是一个Notifier。
我想知道在控制器中设置资源的处理（在本例中为BehaviorSubject及其流的订阅）的正确位置在哪里。
像我在包含的代码中所做的那样，在build()方法中这样做可以吗？
谢谢。
英文:
I am using riverpod_generator in my Flutter app to generate a provider for a controller that I use. The controller is actually a Notifier.
I am wondering where is the correct place in the controller to set up the disposal of resources (in this case, a BehaviorSubject, and its stream's subscription.
Is it ok to do it in the build() method, as I have in the included code?
Thanks
part "provider.g.dart";
final PlayersSearchFiltersValue _initialFilters = PlayersSearchFiltersValue(
searchTerm: "",
);
@riverpod
class PlayersSearchAppController extends _$PlayersSearchAppController
implements PlayersSearchController {
late final PlayersService playersService =
ref.read(playersAppServiceProvider);
final BehaviorSubject<PlayersSearchFiltersValue> _filtersSubject =
BehaviorSubject();
late StreamSubscription<PlayersSearchFiltersValue> _filtersSubscription;
StreamSink<PlayersSearchFiltersValue> get _filtersSink =>
_filtersSubject.sink;
@override
AsyncValue<List<PlayerModel>> build() {
_initializeController();
return AsyncValue.data([]);
}
/// rest of the code
void _initializeController() {
_filtersSubscription = _filtersSubject.stream
.debounceTime(Duration(milliseconds: 500))
.listen((event) {
_onSearchPlayers(event);
});
ref.onDispose(() async {
await _filtersSubscription.cancel();
await _filtersSubject.close();
});
}
}
答案1
得分: 2
是的，这将很好地工作。也许唯一的事情是定义一个单独的 _dispose 方法，并将这部分代码分配给它，以共享责任。
@override
AsyncValue<List<PlayerModel>> build() {
_initializeController();
_dispose();
return AsyncValue.data([]);
}
void _dispose() {
ref.onDispose(() async {
await _filtersSubscription.cancel();
await _filtersSubject.close();
});
}
void _initializeController() {
_filtersSubscription = _filtersSubject.stream
.debounceTime(Duration(milliseconds: 500))
.listen((event) {
_onSearchPlayers(event);
});
}
此外，您应该记住，默认情况下生成器会创建会丢弃其状态的提供程序（例如使用 dispose 修饰符）。要更改此行为，请使用：
@Riverpod(keepAlive: true)
英文:
Yes, this will work great. The only thing, perhaps, is to define a separate _dispose method and allocate this piece of code to it in order to share responsibilities.
@override
AsyncValue<List<PlayerModel>> build() {
_initializeController();
_dispose();
return AsyncValue.data([]);
}
void _dispose() {
ref.onDispose(() async {
await _filtersSubscription.cancel();
await _filtersSubject.close();
});
}
void _initializeController() {
_filtersSubscription = _filtersSubject.stream
.debounceTime(Duration(milliseconds: 500))
.listen((event) {
_onSearchPlayers(event);
});
}
Also, you should remember that generator by default creates providers that dispose their state (as with the dispose modifier). To change this behavior, use:
@Riverpod(keepAlive: true)
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