从 Firestore 检索嵌套对象并放入 Android 中的 RecycleView？

Question

I am trying to populate a RecylerView in Android with attached image data structure in a single document. I want to list out each name, district, image for each ID.

It needs to be done without breaking down in the sub-collection. Is there any possible smart way to populate the RecylerView . Thanks

Here is the sample data I am using. [![enter image description here][1]][1]

Edit 1: I tried to implement the following, does it work?

private void setUpRecyclerView(View view) {

        CheckinList = new ArrayList<>();
        notebookRef.get()
                .addOnSuccessListener(new OnSuccessListener<QuerySnapshot>(){

            @Override
            public void onSuccess(QuerySnapshot queryDocumentSnapshots) {

                for (QueryDocumentSnapshot documentSnapshot : queryDocumentSnapshots) {
                    user user = documentSnapshot.toObject(user.class);

                    HashMap<String, HashMap> about = user.getAbout();
                    for(Map.Entry<String, HashMap> entry : about.entrySet()) {
                        String key = entry.getKey();
                        HashMap<String, HashMap> value = entry.getValue();
                        String Name = "";
                        String District = "";
                        String imageUrl = "";
                        for (Map.Entry<String, HashMap> entry3 : value.entrySet()) {
                            String key3 = entry3.getKey();
                            if (key3 == "name"){
                                Name = entry3.getValue().toString();
                            } else if (key3 == "district"){
                                District = entry3.getValue().toString();
                            } else if (key3 == "imageurl") {
                                imageUrl = entry3.getValue().toString();
                            }
                        }
                        CheckinList.add(new Checkin(Name, District, imageUrl));

                        }

                    }

                }

        });

        adapter = new NoteAdapter(CheckinList, mContext);

        RecyclerView recyclerView = view.findViewById(R.id.recycler_view);
        recyclerView.setHasFixedSize(true);
        recyclerView.setLayoutManager(new LinearLayoutManager(mContext));
        recyclerView.setAdapter(adapter);
    }```

full data scheme screenshot
[![enter image description here][2]][2]


  [1]: https://i.stack.imgur.com/2Jspj.jpg
  [2]: https://i.stack.imgur.com/iwsat.jpg

Answer 1

You need to use nested for loop if number of ID is not large.

if you have access of database you should change the schema to something like this

Document(randomID) -> Collection (about) -> Document (IDs) = Data (name/district/image);

after this you can simply make a nested Firebase query to access data.

Please provide more information if you need help with Firebase query with my given schema or if you want to use your own schema and get the data.

Edit 1

not suggested as this is not the best way of getting data

FirebaseFirestore firebaseFirestore = FirebaseFirestore.getInstance();

firebaseFirestore
    .collection("your collection")
    .document("your doc).get()
    .addOnCompleteListener(new OnCompleteListener<DocumentSnapshot>() {
    @Override
    public void onComplete(@NonNull Task<DocumentSnapshot> task) {
        if (task.isSuccessful()){
            int docSize = 10; //size of IDs (assuming 10)
            for (int index = 0; index <= docSize; index++){
                HashMap<String, Object> dataMap = (HashMap<String, Object>) task.getResult().get("1000000"+index);
                //you have data in dataMap
            }
        }
    }
});

Sorry not sure about the result as I don't have full information, you need to modify the code. Please edit my answer if you get success.

Still suggesting to change the schema

Hope this will help!