ObservableMap not notifying Observer mobx 2.2.3 it was woking fine in 2.2.1

[boradparas]

I am using so many ObservableMaps in the app and none of them are updating the UI since I upgraded to 2.2.3

@observable ObservableMap<String, ParticipantExtended> sortedParticipants = ObservableMap<String, ParticipantExtended>();

Observer(
                          builder: (_) {
                            return SliverGrid(
                              gridDelegate:
                                  SliverGridDelegateWithFixedCrossAxisCount(
                                crossAxisCount: crossAxisCount,
                                childAspectRatio: tileWidth / tileHeight,
                                crossAxisSpacing: 2,
                                mainAxisSpacing: 2,
                              ),
                              delegate: SliverChildBuilderDelegate(
                                (context, index) {
                                  final participant = videoRoomStore
                                      .sortedParticipants.values
                                      .elementAt(index);
                                 return VisibilityDetector(
                                    key: Key(participant.identity),
                                    onVisibilityChanged: (info) {
                                      final bool isVisible =
                                          info.visibleFraction > 0;
                                      final bool isCompletelyGone =
                                          info.visibleFraction == 0;
                                      final bool isSubscribed = videoRoomStore
                                                  .participantSubscriptions[
                                              participant.identity] ??
                                          false;
                                      final bool shouldSubscribe =
                                          !isSubscribed &&
                                              isVisible &&
                                              !participant.isLocalParticipant;

                                      if (shouldSubscribe) {
                                        videoRoomStore.subscribeToVideoTracks(
                                          participant.participant
                                              as RemoteParticipant,
                                        );
                                        videoRoomStore.visibleParticipants[
                                            participant.identity] = true;
                                      } else if (!participant
                                              .isLocalParticipant &&
                                          isCompletelyGone) {
                                        videoRoomStore.unSubscribeToVideoTracks(
                                          participant.participant
                                              as RemoteParticipant,
                                        );
                                        videoRoomStore.visibleParticipants
                                            .remove(
                                          participant.identity,
                                        );
                                      }
                                    },
                                    child: ParticipantTile(
                                      participant: participant,
                                    ),
                                  );
                                },
                                childCount: videoRoomStore.isAppInForeground
                                    ? videoRoomStore.sortedParticipants.length
                                    : 0,
                              ),
                            );
                          },
                        ),

What change I need to make to keep it working as earlier it used to work?

[amondnet]

@boradparas The issue may be related to this PR. Since 2.2.3, mobx checks for equality of map, iterable with DeepCollectionEquality.

Could you try one of the following?

1. use @alwaysNotify instead of @observable.

    @alwaysNotify 
    ObservableMap<String, ParticipantExtended> sortedParticipants = ObservableMap<String, ParticipantExtended>();

2. override == and hashCode in ParticipantExtended. Avoid unnecessary observable notifications of Iterable or Map fields.

[alxmoroz]

Same for ObservableList etc.

How can I notify observer now, when changing attrs on objects within list or map? Equality checks only addresses in memory, but not theirs contents...

Is this tool only suitable for simple lists of strings and numbers? Previously, it was possible to work with objects.

[amondnet]

@alexggordon

How can I notify observer now, when changing attrs on objects within list or map? Equality checks only addresses in memory, but not theirs contents...

Can you please provide reproducible code? Then I can tell you how to do it. Alternatively, see the documentation.

Could you try one of the following?

1. use @alwaysNotify.
2. override == and hashCode in Object
3. use immutable data class

https://github.com/mobxjs/mobx.dart/issues/851

[amondnet]

https://github.com/mobxjs/mobx.dart/pull/970

[alxmoroz]

@amondnet

Could you try one of the following?

1. use @alwaysNotify.

I tried it. Without changes. Perhaps I didn’t fully understand how to apply it correctly.

2. override == and hashCode in Object
3. use immutable data class

Looks like a suitable solution. I'll try this approach. Thank you very much!

[amondnet]

https://github.com/mobxjs/mobx.dart/pull/971

Make the change in 2.2.3 optional. If you want the use this behavior , modify @observable to @MakeObservable(useDeepEquality: true).