getValue<T> static method

Future<T?> getValue<T>(String key, { T? defaultValue, })

Reads a value back out of shared storage.

The store is not write-only: the widget writes to it too. An MToggleAction flips its bool on-device with the app closed, and a declared refresh: source stores what it fetched — neither is visible to the app without reading it back.

T may be String, bool, int, double, or List<dynamic> / Map<String, dynamic> for values written with saveList / saveJson. Returns defaultValue when the key is absent or holds another type.

Implementation

static Future<T?> getValue<T>(String key, {T? defaultValue}) async {
  try {
    final raw = await _channel.invokeMethod<Object?>('getValue', {
      'key': key,
      'appGroupId': _appGroupId,
    });
    if (raw == null) return defaultValue;
    if (raw is T) return raw as T;

    // Android keeps everything as strings, so coerce rather than fail.
    final text = raw.toString();
    if (T == String) return text as T;
    if (T == bool) {
      return (text == 'true' || text == '1') as T;
    }
    if (T == int) return (int.tryParse(text) ?? defaultValue) as T?;
    if (T == double) return (double.tryParse(text) ?? defaultValue) as T?;
    // Parenthesised: bare `T == List<dynamic>` parses the angle bracket as a
    // comparison operator.
    if (T == (List<dynamic>) || T == (Map<String, dynamic>)) {
      return jsonDecode(text) as T;
    }
    return defaultValue;
  } on PlatformException {
    return defaultValue;
  } on FormatException {
    return defaultValue;
  }
}