Detected objects stream controller from Firestore

detectedObjects.dart

StreamController<DetectedObject?> controller = StreamController<DetectedObject?>();

void dispose() {
  controller.close();
}

void handle(DetectedObject data) async {
  // Your handling logic for the detected object
}

// Modify this to match your DetectedObject structure
CollectionReference<DetectedObject> collectionRef = firestore.collection(PATH).withConverter<DetectedObject>(
  fromFirestore: (snapshot, _) => DetectedObject.fromJson(snapshot.data()!),
  toFirestore: (detectedObject, _) => detectedObject.toJson(),
);

collectionRef
    .where('userID', isEqualTo: USER_ID)
    // ...Other criteria
    .orderBy('date', descending: true)
    .limit(1)
    .snapshots(includeMetadataChanges: false)
    .asyncMap((event) async* {
      for (var change in event.docChanges) {
        final data = change.doc.data();
        final date = data?.date;
        final fifteenSecondsAgo = DateTime.now().subtract(const Duration(seconds: 15));

        // Choose the most recent document
        // (you can modify this based on your needs)
        if (date != null && date.compareTo(fifteenSecondsAgo) > 0) {
          yield data;
        }
      }
    })
    .listen(controller.add);