network_resource 0.0.4

Automatically cache network resources and use them when offline.

network_resource

Automatically cache network resources and use them when offline.

NetworkResource fetches data over HTTP, caches it in a file, and holds it in memory. The main method, get(), will return the value in memory, cache, or fetch from the network -- in that order. If the cache file is older than maxAge, the cache will be updated from the network if available. To manually refresh, use get(forceReload: true) or getFromNetwork(). The latter can be used to avoid cache fallback.

Example

There are three concrete classes included.

• StringNetworkResource
• StringListNetworkResource
• BinaryNetworkResource

// String data.
final eventsResource = StringNetworkResource(
  url: 'https://example.com/events.json',
  filename: 'events.json',
  maxAge: Duration(minutes: 60),
);

// Binary data.
final photo = BinaryNetworkResource(
  url: 'https://example.com/photo.png',
  filename: 'photo.png',
  maxAge: Duration(hours: 24),
);

// A string list, line by line.
 final words = StringListNetworkResource(
  url: 'https://example.com/wordlist.txt',
  filename: 'wordlist.txt',
  maxAge: Duration(hours: 24),
);

// Parsing a JSON string into a `List<Event>`.
json.decode(data).forEach((item) => events.add(Event(item)));

See ./example/main.dart for a full example with pull to refresh.

TODO

• Make maxAge optional.
• Make holding the raw value in memory optional.
• Consider supporting HTTP POST.