Bind Android textview to firebase database field

Issue

I have a textView in my activity - say, "Username". It is supposed to be populated from a Firebase database. I am making the Firebase query in Asynctask so as not to block the activity. However that means that the TextView loads first, before the Firebase query is completely executed.

So what is the best way to refresh this textBox after the Firebase query is executed inside the AsyncTask and the username gets known? I do not want to showprogressBar and block the activity while the data is being fetched from the database. That would defeat the purpose of doing it in AsyncTask.

Code for the AsyncTask is below

   private class CheckUserLoginAndRetrieveDataFromFirebase extends AsyncTask <Void, Void, Void> {
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
    }


    @Override
    protected Void doInBackground(Void... voids) {
        if (thisAppUser!=null) {
            setUserDataForToday();  
            if (createNewNode) { //This is the first time the User is logging in
                createUsersNodesForFirstTime();
            }
        }
        return null;
    }

Code for my Firebase Query in the AsyncTask is below

public static void setUserDataForToday() {
    setProperDatabaseReference(); //This sets reference to user specific nodes in the database
    myRef.child("dashboard").addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            Dashboard dashboard = dataSnapshot.getValue(Dashboard.class);
            if (dataSnapshot.getChildrenCount() > 0) {
                createNewNode = false;
                if (dashboard.checkIfTodaysDateExistsInDatabase()) {
                    //An entry for todays date exists in database, so no data change needed
                    myDashboard = dashboard;
                } 

Solution

I hope this example will help you

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        setUserDataForToday();
        Log.d("MainActivity", "Process is not blocked");
    }

    public void setUserDataForToday() {
        Log.d("MainActivity", "Called method");
        DatabaseReference database = FirebaseDatabase.getInstance().getReference();
        database.child("users").child("1").child("name").addListenerForSingleValueEvent(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                if (dataSnapshot.exists()) {
                    String userName = dataSnapshot.getValue(String.class);
                    Log.d("MainActivity", "Received value: " + dataSnapshot.getValue());
                    dataSnapshot.getKey();
                    TextView textView = (TextView) findViewById(R.id.textUserName);
                    textView.setText(userName);
                }
            }
            @Override
            public void onCancelled(DatabaseError databaseError) {
                Log.d("MainActivity", "DB error: " + databaseError.getMessage());
            }
        });
    }

    public void onClick(View v) {
        setUserDataForToday();
    }
}

Answered By - Vladimir Mezentsev