flutter-caching-data

Build a repository that yields local database data immediately, then fetches remote data, updates the cache, and yields the fresh result. For writes, save locally with a synchronized flag set to false and push pending records via a background task using workmanager or a Timer.

Use shared_preferences for small non-critical settings, sqflite, Drift, Hive CE, or Isar for large structured datasets, and path_provider with the file system for binary data or media. Match the storage mechanism to the data size and lifecycle.

Use the cached_network_image package to handle file-system caching of remote images automatically. For custom ImageProviders, override createStream and resolveStreamForKey, and increase ImageCache.maxByteSize when loading images larger than the default cache.

Pre-warm a FlutterEngine in the Application class, execute the Dart entrypoint, and store it in FlutterEngineCache with an ID. Then launch screens using FlutterActivity.withCachedEngine, setting any initial route on the engine's navigation channel beforehand.

Overriding operator == on Widget objects causes O(N²) behavior during rebuilds, degrading performance. The only exception is leaf widgets with rarely changing properties where comparison is cheaper than rebuilding; otherwise prefer const constructors.