How to use firebase database from broadcastreceiver

Question

I'm trying to use Firebase Database from a BroadcastReceiver to fetch some data. Unfortunately the user is null sometimes, which means I can't use the UID the fetch data.

@Override
public void onReceive(final Context context, Intent intent) { 
    FirebaseAuth.getInstance().addAuthStateListener(new FirebaseAuth.AuthStateListener() {
                @Override
                public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
                    FirebaseUser user = firebaseAuth.getCurrentUser();
                    if(user != null){
                        //sometimes not null
                    }else{
                        //sometimes null
                    }
                }
     });
}

Also FirebaseAuth.getInstance().getCurrentUser is null sometimes. Also, i'm not running long time opertaion inside my broadcastreceiver. I'm talking about fetching a single opjes without any nodes under it.

How can I use Firebase database from a BroadcastReceiver?

Answer 1

Try delegating to an intent service like this

public class AuthenticationCheckService extends IntentService {

public AuthenticationCheckService() {
    super("AuthenticationCheckService");
}

@Override
protected void onHandleIntent(@Nullable Intent intent) {
    //Once this code runs and its done the service stops so need to worry about long running service
    checkAuthenticationStatus();
}

private void checkAuthenticationStatus() {
    FirebaseAuth.getInstance().addAuthStateListener(new FirebaseAuth.AuthStateListener() {
    @Override
    public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth)  {
        FirebaseUser user = firebaseAuth.getCurrentUser();
        if (user != null) {
            //Do stuffs
        } else {
            //Resolve to authentication activity
        }
    }
});
}
}

Then start the service inside the onReceive method like this

@Override
public void onReceive(final Context context, Intent intent) { 
 //Method implemented below  
 checkAuthStatus(context);

}

private void checkAuthStatus(Context context) {
    Intent authCheckIntent = new Intent(context, AuthenticationCheckService.class);
    context.startService(authCheckIntent);
}

then remember to register the service in your manifest file

 <service android:name=".AuthenticationCheckService" />

Answer 2

BroadcastReceiver aren't meant to be used for long-running operations, try starting IntentService from that receiver instead. Android will finish this receiver if work takes too long. Maybe, that is the reason why the result is null sometimes.