unsubscribe method

void unsubscribe(
  1. String collection, [
  2. void callback(
    1. RealtimeEvent
    )?
])

Unsubscribes from a collection

Implementation

void unsubscribe(String collection, [void Function(RealtimeEvent)? callback]) {
  if (!_listeners.containsKey(collection)) return;

  if (callback != null) {
    _listeners[collection]!.remove(callback);
  }

  if (callback == null || _listeners[collection]!.isEmpty) {
    _listeners.remove(collection);

    // Send unsubscribe message
    _send({
      'type': 'unsubscribe',
      'channel': collection,
    });
  }
}