I have the below function for private chat notifications in Flutter. I’d like to do the same for a group chat where there are multiple recipentids. How can I achieve that by having multiple recipientids in an array so all the users (except the sender) get notified?

gmNotification(String recipientid) {
    String notificationid = const Uuid().v1();
    String res = "Some error occurred";
    try {{
          FirebaseFirestore.instance
              .collection('notifications')
              .doc(recipientid)
              .collection('private-message-notifications')
              .doc(notificationid)
              .set({
              'notificationid': notificationid,
              'timestamp': DateTime.now(),
              },
          );
      }
      res = 'success';
    } catch (err) {
      res = err.toString();
    }
    return res;
  }

>Solution :

You can modify your gmNotification function to accept an array of recipientids instead of a single recipientid, and then loop through the array to create notifications for each recipient. Here’s an example:

gmGroupNotification(List<String> recipientids) {
    String notificationid = const Uuid().v1();
    String res = "Some error occurred";
    try {
      for (String recipientid in recipientids) {
        FirebaseFirestore.instance
            .collection('notifications')
            .doc(recipientid)
            .collection('group-message-notifications')
            .doc(notificationid)
            .set({
              'notificationid': notificationid,
              'timestamp': DateTime.now(),
            });
      }
      res = 'success';
    } catch (err) {
      res = err.toString();
    }
    return res;
  }