Dmitry
ffc5ed959a
CacheInterceptor кэширует каждый успешный GET по путь+параметры в drift (sqlite нативно, wasm+OPFS в браузере) и подменяет им сетевую ошибку; провайдер отдаёт Cached<T>, экран показывает баннер «данные на …». Контракт для остальных экранов — docs/ai/offline-cache.md. flake.nix: libsecret/pkg-config для линуксовой сборки, jq/curl для just app-web-assets (сборка sqlite3.wasm + drift_worker.js).
32 lines
1.1 KiB
Dart
32 lines
1.1 KiB
Dart
import 'package:dio/dio.dart';
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/// A value from the API, or the last one [CacheInterceptor] had on file for the
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/// same endpoint+params when the live request failed. `fetchedAt` is null for
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/// a live answer — that is the one bit a screen needs to decide whether to
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/// show a `StaleBanner`. See `docs/ai/offline-cache.md`.
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class Cached<T> {
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const Cached(this.data, {this.fetchedAt});
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final T data;
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final DateTime? fetchedAt;
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}
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extension CachedResponseX<T> on Response<T> {
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/// Wraps this response's data with the staleness [CacheInterceptor] recorded
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/// in `extra['fetchedAt']`. A provider that wants offline support returns
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/// `r.cached` instead of `r.data!`.
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Cached<T> get cached => Cached(data as T, fetchedAt: extra['fetchedAt'] as DateTime?);
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}
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/// The oldest of several fetch times, or null if none of them is stale.
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/// Screens with several cached providers show one banner for the lot rather
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/// than one per tile.
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DateTime? oldestFetch(Iterable<DateTime?> fetchedAt) {
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DateTime? oldest;
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for (final at in fetchedAt) {
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if (at == null) continue;
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if (oldest == null || at.isBefore(oldest)) oldest = at;
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}
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return oldest;
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}
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