subscribe method

VoidCallback subscribe(
  1. TTOnCb listener
)

Subscribe to updates and receive a disposer callback.

Implementation

VoidCallback subscribe(TTOnCb listener) {
  if (key == '') {
    // TODO: "Map logic"
  }

  _updateEvent.on(listener);
  if (isNull(_endQuery)) {
    _endQuery = _client.graph.query(getPath(), _onQueryResponse);
  }
  if (_hasReceived) {
    listener(_lastValue, key);
  }
  return () => unsubscribe(listener);
}