Tukukkk

I'm new to Android development and need help with populating data from Firebase Realtime database into the FirebaseRecyclerAdapter.

My app has a list of workshops. A user can log in to my test app with a GitHub auth and I get a user email to sign in or out from the workshop if the relevant button is pressed.

So in some point, my workshop contains a list of users as per the example below in Firebase.

The problem is that I need to highlight workshops that users have already signed into in the recycler view.

The main issue I face is when populating the info for each workshop. I can easily get the users to list separately later, but I don't know how to do this within one nice Workshop object from the very beginning.

I'm lost. Please help.

My FirebaseRecyclerAdapter:

public class WorkshopsFirebaseRecyclerAdapter extends FirebaseRecyclerAdapter<Workshop, WorkshopViewHolder> {



    private Context mContext;

    private ProgressBar progressBar;



    public WorkshopsFirebaseRecyclerAdapter(FirebaseRecyclerOptions<Workshop> options, Context context, ProgressBar view) {

        super(options);

        mContext = context;

        progressBar = view;

    }



    @Override

    public void onDataChanged() {

        if (progressBar != null) {

            progressBar.setVisibility(View.GONE);

        }

    }



    @Override

    protected void onBindViewHolder(@NonNull final WorkshopViewHolder holder, final int position, @NonNull final Workshop model) {



        final Workshop workshop = getItem(position);

        final String id = getRef(position).getKey();



        holder.date.setText(getUserFriendlyDate(workshop.getDate()));

        holder.description.setText(workshop.getDescription());



        if (workshop.getWorkshopAttendants() != null){

            Timber.i("onBindViewHolder workshop is %s", workshop.toString());

        }



        holder.getView().setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                TinyDB tinyDB = new TinyDB(mContext);

                tinyDB.putObject(mContext.getString(R.string.workshop_tinydb_key), workshop);

                Intent intent = new Intent(mContext, WorkshopDetailsActivity.class);

                intent.putExtra(mContext.getString(R.string.open_workshop_details_intent_key),

                        WorkshopDetailsActivity.INTENT_OPEN_UPDATE_WORKSHOP_DETAILS);

                intent.putExtra(mContext.getString(R.string.current_workshop_id_key), id);

                mContext.startActivity(intent);

            }

        });

    }



    @Override

    public WorkshopViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {

        View itemView = LayoutInflater.from(viewGroup.getContext())

                .inflate(R.layout.workshop_rv_item, viewGroup, false);

        return new WorkshopViewHolder(itemView);

    }



    private String getUserFriendlyDate(String dateOld){

        Date date = new Date();

        SimpleDateFormat oldDateFormat = new SimpleDateFormat("dd-MM-yyyy", Locale.UK);

        try {

            date = oldDateFormat.parse(dateOld);

        } catch (ParseException e) {

            e.printStackTrace();

        }

        SimpleDateFormat newDateFormat = new SimpleDateFormat("dd MMM yyyy", Locale.UK);

        return newDateFormat.format(date);

    }



}

My method where I set adapter and query:

 private void loadWorkshopsForCity(String city) {

        Query query;

        if (city.equals(getString(R.string.spinner_cities_all_value))) {

            query = FirebaseDatabase.getInstance()

                    .getReference(getString(R.string.firebase_root_name))

                    .child(getString(R.string.firebase_workshops_root_name))

                    .limitToLast(50);

        } else {

            query = FirebaseDatabase.getInstance()

                    .getReference(getString(R.string.firebase_root_name))

                    .child(getString(R.string.firebase_workshops_root_name))

                    .orderByChild(getString(R.string.firebase_workshop_city_name_key))

                    .equalTo(city);

        }



        query.addListenerForSingleValueEvent(new ValueEventListener() {

            @Override

            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {

                for (DataSnapshot workshopSnapshot : dataSnapshot.getChildren()) {

                    Workshop workshop = workshopSnapshot.getValue(Workshop.class);

                    for(DataSnapshot usersSnapshot : workshopSnapshot.child("users").getChildren()){

                        if (usersSnapshot.exists()){

                            WorkshopAttendant user = usersSnapshot.getValue(WorkshopAttendant.class);

                            if (user!=null){

                                users.add(user);

                            }

                        }

                    }

                    if (users.size()!=0){

                        workshop.setWorkshopAttendants(users);

                    }

                }

            }





            @Override

            public void onCancelled(@NonNull DatabaseError databaseError) {

                Timber.i(databaseError.toException());

            }

        });



        FirebaseRecyclerOptions<Workshop> options =

                new FirebaseRecyclerOptions.Builder<Workshop>()

                        .setQuery(query, Workshop.class)

                        .build();



        if (adapter != null) {

            adapter.stopListening();

        }



        adapter = new WorkshopsFirebaseRecyclerAdapter(options, this, progressBar);

        mRecyclerView.setLayoutManager(new LinearLayoutManager(this));

        mRecyclerView.setAdapter(adapter);

        adapter.startListening();



    }

my Workshop that contains Attendants list:

public class Workshop {



    private String date;

    private String time;

    private String description;

    private String name;

    private String address;

    private String city;

    private List<WorkshopAttendant> workshopAttendants;



    private boolean isChecked;



    // empty constructor for firebase

    public Workshop() {

    }



    public Workshop(String date, String time, String description, String name, String address, String city,

                    List<WorkshopAttendant> workshopAttendants) {

        this.date = date;

        this.time = time;

        this.description = description;

        this.name = name;

        this.address = address;

        this.city = city;

        this.workshopAttendants = workshopAttendants;

    } .....

and other WorkshopAttendant that should be inside Workshop object.

public class WorkshopAttendant {



    private String email;

    private int role; // 1 - coach ; 0 - organiser ; 2 - student



    public WorkshopAttendant(String userEmail, int role) {

        this.email = userEmail;

        this.role = role;

    }



    // for firebase

    public WorkshopAttendant() {

    }

1) List workshopAttendants in Workshop model to Map users = new HashMap<>();

2) used new SnapshotParser for my Recycler options;

FirebaseRecyclerOptions<Workshop> options =

                new FirebaseRecyclerOptions.Builder<Workshop>()

                        .setQuery(query, new SnapshotParser<Workshop>() {

                            @NonNull

                            @Override

                            public Workshop parseSnapshot(@NonNull DataSnapshot snapshot) {

                                GenericTypeIndicator<Workshop> t = new GenericTypeIndicator<Workshop>() {};

                                Workshop workshop = snapshot.getValue(t);

                                return workshop;

                            }

                        })

                .build();

3) in my adapter I set check for users so now can mark workshops that have users signed for.

try {

            Map<String, User> users = workshop.getValue();

            if (users.size()!=0){holder.description.setBackgroundColor(mContext.getColor(R.color.colorPrimaryDark));

            }

        } catch (NullPointerException e){

            Timber.i(e, "no users for %s", workshop.getDescription());

        }

thanks, @AlexMamo for patience