hydrate method

Signal<T> hydrate({ required String key, required T fromJson(String value), required String toJson(T value), SignalStorage? storage, })

Hydrates (persists) the current signal using the provided storage or globalSignalStorage.

It immediately reads the stored value associated with key. If a value is found, it updates the signal's value silently. It then registers a lightweight change listener to write subsequent values without preventing auto-disposal.

Implementation

Signal<T> hydrate({
  required String key,
  required T Function(String value) fromJson,
  required String Function(T value) toJson,
  SignalStorage? storage,
}) {
  final activeStorage =
      storage ?? globalSignalStorage ?? _fallbackSignalStorage;
  try {
    final stored = activeStorage.read(key);
    if (stored != null) {
      setValueSilently(fromJson(stored));
    }
  } catch (_) {
    // Ignore initial read error to allow fallback/empty state
  }

  void persist(T previous, T current) {
    try {
      activeStorage.write(key, toJson(current));
    } catch (_) {
      // Ignore write errors
    }
  }

  // Persist the hydrated/default value immediately, then future changes.
  persist(value, value);
  addChangeListener(persist);

  return this;
}