Files
App/lib/pods/paging.dart

121 lines
2.6 KiB
Dart

import 'dart:async';
import 'package:hooks_riverpod/hooks_riverpod.dart';
abstract class PaginationController<T> {
int? get totalCount;
int get fetchedCount;
bool get fetchedAll;
FutureOr<List<T>> fetch();
Future<void> refresh();
Future<void> fetchFurther();
}
abstract class PaginationFiltered<F> {
late F currentFilter;
Future<void> applyFilter(F filter);
}
mixin AsyncPaginationController<T> on AsyncNotifier<List<T>>
implements PaginationController<T> {
@override
int? totalCount;
@override
int get fetchedCount => state.value?.length ?? 0;
@override
bool get fetchedAll => totalCount != null && fetchedCount >= totalCount!;
@override
FutureOr<List<T>> build() async => fetch();
@override
Future<void> refresh() async {
totalCount = null;
state = AsyncData<List<T>>([]);
final newState = await AsyncValue.guard<List<T>>(() async {
return await fetch();
});
state = newState;
}
@override
Future<void> fetchFurther() async {
if (fetchedAll) return;
state = AsyncLoading<List<T>>();
final newState = await AsyncValue.guard<List<T>>(() async {
final elements = await fetch();
return [...?state.valueOrNull, ...elements];
});
state = newState;
}
}
mixin FamilyAsyncPaginationController<T, Arg>
on AutoDisposeFamilyAsyncNotifier<List<T>, Arg>
implements PaginationController<T> {
@override
int? totalCount;
@override
int get fetchedCount => state.value?.length ?? 0;
@override
bool get fetchedAll => totalCount != null && fetchedCount >= totalCount!;
@override
FutureOr<List<T>> build(Arg arg) async => fetch();
@override
Future<void> refresh() async {
totalCount = null;
state = AsyncData<List<T>>([]);
final newState = await AsyncValue.guard<List<T>>(() async {
return await fetch();
});
state = newState;
}
@override
Future<void> fetchFurther() async {
if (fetchedAll) return;
state = AsyncLoading<List<T>>();
final newState = await AsyncValue.guard<List<T>>(() async {
final elements = await fetch();
return [...?state.valueOrNull, ...elements];
});
state = newState;
}
}
mixin AsyncPaginationFilter<F, T> on AsyncPaginationController<T>
implements PaginationFiltered<F> {
@override
Future<void> applyFilter(F filter) async {
if (currentFilter == filter) return;
// Reset the data
totalCount = null;
state = AsyncData<List<T>>([]);
currentFilter = filter;
final newState = await AsyncValue.guard<List<T>>(() async {
return await fetch();
});
state = newState;
}
}