subscribeWithPrevious<T> method

void Function() subscribeWithPrevious<T>(Pod<T> pod, void handler(T? previous, T value), { bool fireImmediately = false, })

Listen to changes of a pod's state, and retrieve the latest value.

Implementation

void Function() subscribeWithPrevious<T>(
  Pod<T> pod,
  void Function(T? previous, T value) handler, {
  bool fireImmediately = false,
}) {
  final node = _ensureNode(pod);

  var previousValue = node._value as T?;

  return subscribe(
    pod,
    (T nextValue) {
      handler(previousValue, nextValue);
      previousValue = nextValue;
    },
    fireImmediately: fireImmediately,
  );
}