Android Firestore convert array of document references to List

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半阙折子戏 2020-11-27 23:07

In my Firestore I\'ve got a users collection, within which the documents could have a bookmarks field, which is an array of references:

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难免孤独 (楼主)

2020-11-27 23:58

Yes it is. Please see the following lines of code:

FirebaseUser firebaseUser = FirebaseAuth.getInstance().getCurrentUser();
if (firebaseUser != null) {
    String uid = firebaseUser.getUid();
    rootRef.collection("users").document(uid).get().addOnCompleteListener(new OnCompleteListener() {
        @Override
        public void onComplete(@NonNull Task task) {
            if (task.isSuccessful()) {
                DocumentSnapshot document = task.getResult();
                if (document.exists()) {
                    List list = (List) document.get("bookmarks");
                    List> tasks = new ArrayList<>();
                    for (DocumentReference documentReference : list) {
                        Task documentSnapshotTask = documentReference.get();
                        tasks.add(documentSnapshotTask);
                    }
                    Tasks.whenAllSuccess(tasks).addOnSuccessListener(new OnSuccessListener>() {
                        @Override
                        public void onSuccess(List