registerListener method

void registerListener({
  1. required String key,
  2. required ValueChanged<String?> listener,
})

Register listener for key with the value injected for the listener. The listener will still be called when you delete the key with the injected value as null. This listener will be added to the list of registered listeners for that key.

Implementation

void registerListener({
  required String key,
  required ValueChanged<String?> listener,
}) {
  _listeners[key] = [..._listeners[key] ?? [], listener];
}