Login with different console Firebase (different users)?

Question

it's possible to create an android application(related to Firebase) which provides to every user the ability to connect to his own firebase , without sharing his information with other users( not the collaboration method ,generally, the app is about to track object : the user connect to app , get the object information and store it in his account and than track it) .. so any solution for the login process ?

Answer 1

Which backend resources your Android code connects to is determined by the FirebaseApp instance. The default app is usually initialized from the google-services.json that you add to your project, so can't be dynamically changed from within the code.

But you can also initialize a FirebaseApp instance from within your Android code. All you need is the pertinent information from the Firebase project of the user, which would otherwise be read from their google-services.json. You'll want to build a FirebaseOptions object in that case, which contains things like the Application ID, Project ID, Database URL and a few more values.

Once you have a FirebaseApp, you can then get the other Firebase services from that. It's quite similar to my answer on accessing multiple databases in a single app from a few years ago. From there:

FirebaseOptions options = new FirebaseOptions.Builder()
        .setApiKey("AI...j0")
        .setApplicationId("1:5...e0")
        .setDatabaseUrl("https://myapp.firebaseio.com")
        .build();
FirebaseApp secondApp = FirebaseApp.initializeApp(getApplicationContext(), options, "second app");
FirebaseDatabase secondDatabase = FirebaseDatabase.getInstance(secondApp);
secondDatabase.getReference().setValue(ServerValue.TIMESTAMP);