1 | initial version |
Here are the steps to retrieve information for a specific user from the Firestore database and display it in a RecyclerView on an Android device:
implementation 'com.google.firebase:firebase-firestore:19.1.1'
FirebaseFirestore db = FirebaseFirestore.getInstance();
CollectionReference usersRef = db.collection("users");
Query query = usersRef.whereEqualTo("userID", "MY_USER_ID");
Replace MYUSERID with the ID of the specific user you want to retrieve information for.
FirestoreRecyclerOptions<User> options = new FirestoreRecyclerOptions.Builder<User>()
.setQuery(query, User.class)
.build();
Replace User with the name of your user object model class.
public class UserAdapter extends FirestoreRecyclerAdapter<User, UserAdapter.UserViewHolder> {
// ...
}
Implement the necessary methods in the adapter class, including onCreateViewHolder(), onBindViewHolder(), getItemCount(), and any additional methods needed for your specific use case.
Instantiate the RecyclerView and set the adapter in your main activity.
RecyclerView recyclerView = findViewById(R.id.recycler_view);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
UserAdapter adapter = new UserAdapter(options);
recyclerView.setAdapter(adapter);
public class UserViewHolder extends RecyclerView.ViewHolder {
TextView nameTextView;
TextView emailTextView;
public UserViewHolder(@NonNull View itemView) {
super(itemView);
nameTextView = itemView.findViewById(R.id.name_text_view);
emailTextView = itemView.findViewById(R.id.email_text_view);
}
public void bind(User user) {
nameTextView.setText(user.getName());
emailTextView.setText(user.getEmail());
}
}
Replace nametextview and emailtextview with the IDs of the TextViews in your RecyclerView item layout.