Flutter › REST API Integration in Flutter

How should you properly design your repository layer to genuinely support offline first behavior, correctly falling back to previously cached data whenever the device genuinely currently has no active internet connection?

Intermediate

Answer

Designing a genuinely offline first repository typically involves properly checking a local cache, such as one backed by Hive or SQLite, first before attempting a live network request, then updating that same local cache with the genuinely latest freshly fetched data whenever a network request actually genuinely succeeds, and properly falling back to serving that existing previously cached data whenever the device genuinely currently has no active internet connection at all, letting your app remain genuinely usable, even if only showing potentially somewhat outdated data, rather than simply displaying a completely broken, empty error screen whenever connectivity is genuinely temporarily unavailable.
Future<List<Order>> fetchOrders() async {
  try {
    final orders = await api.fetchOrders();
    await cache.saveOrders(orders);
    return orders;
  } catch (e) {
    return await cache.getCachedOrders();
  }
}
Real-world example A delivery tracking app properly falls back to displaying a customer's own previously cached order status whenever their device genuinely loses internet connectivity while actively out on a delivery route, rather than the app becoming completely unusable and simply displaying an empty broken error screen.

Common follow-ups: How do you actually properly indicate to the user that they are currently viewing potentially outdated cached data rather than genuinely fresh data?;What genuinely other specific offline first strategies exist beyond simply this particular fallback approach?