signInWithEmailAndPassword from Activity to Fragment

Question

I am new to Android Development, I have a problem to passing firebase auth from SignInActivity to HomeFragment. Here's the code

public class SignInActivity extends AppCompatActivity {

private EditText inputEmail, inputPassword;
private FirebaseAuth auth;
private ProgressBar progressBar;
private Button btnSignIn, btnResetPassword;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    //Get Firebase Auth Instance
    auth = FirebaseAuth.getInstance();

    setContentView(R.layout.activity_sign_in);

    inputEmail = (EditText) findViewById(R.id.email);
    inputPassword = (EditText) findViewById(R.id.password);
    progressBar = (ProgressBar) findViewById(R.id.progressBar);
    btnSignIn = (Button) findViewById(R.id.action_sign_in_button);
    btnResetPassword = (Button) findViewById(R.id.intent_reset_password_button);

    btnSignIn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String email = inputEmail.getText().toString();
            final String password = inputPassword.getText().toString();

            if (TextUtils.isEmpty(email)) {
                Toast.makeText(getApplicationContext(), "Enter Email Address", Toast.LENGTH_SHORT).show();
                return;
            }
            if (TextUtils.isEmpty(password)) {
                Toast.makeText(getApplicationContext(), "Enter Password", Toast.LENGTH_SHORT).show();
                return;
            }

            progressBar.setVisibility(View.VISIBLE);

            //Authenticate User
            auth.signInWithEmailAndPassword(email, password)
                    .addOnCompleteListener(SignInActivity.this, new OnCompleteListener<AuthResult>() {
                        @Override
                        public void onComplete(@NonNull Task<AuthResult> task) {
                            // If sign in fails, display a message to the user. If sign in succeeds
                            // the auth state listener will be notified and logic to handle the
                            // signed in user can be handled in the listener.
                            progressBar.setVisibility(View.GONE);
                            if (!task.isSuccessful()) {
                                //There was an Error
                                if (password.length() < 6) {
                                    inputPassword.setError(getString(R.string.minimum_password));
                                } else {
                                    Toast.makeText(SignInActivity.this, getString(R.string.auth_failed), Toast.LENGTH_SHORT).show();
                                }
                            } else {
                                HomeFragment fragment = new HomeFragment();
                                FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
                                transaction.replace(R.id.home_fragment, fragment);
                                transaction.commit();
                            }
                        }
                    });
        }
    });
}

}

and here's the HomeFragment fragment

public class HomeFragment extends Fragment {

public HomeFragment() {
    // Required empty public constructor
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    return inflater.inflate(R.layout.fragment_home, container, false);
}

}

and here's the logcat

FATAL EXCEPTION: main Process: clouwiko.dev.prasiku, PID: 30462 java.lang.RuntimeException: clouwiko.dev.prasiku.activity.SignInActivity@3039242e must implement OnFragmentInteractionListener at clouwiko.dev.prasiku.fragment.HomeFragment.onAttach(HomeFragment.java:84) at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1363) at android.support.v4.app.FragmentTransition.addToFirstInLastOut(FragmentTransition.java:1187) at android.support.v4.app.FragmentTransition.calculateFragments(FragmentTransition.java:1070) at android.support.v4.app.FragmentTransition.startTransitions(FragmentTransition.java:115) at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2374) at android.support.v4.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManager.java:2332) at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:2239) at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:700) at android.os.Handler.handleCallback(Handler.java:739) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:145) at android.app.ActivityThread.main(ActivityThread.java:5942) at java.lang.reflect.Method.invoke(Native Method) at java.lang.reflect.Method.invoke(Method.java:372) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1400) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1195)

the app always crashes after i click sign in, could you please help me. thank you

Levi Moreira Levi Moreira · Accepted Answer · 2018-02-12T15:57:02

Your problem is clear:

clouwiko.dev.prasiku.activity.SignInActivity@3039242e must implement OnFragmentInteractionListener

You need to implement a way to your fragment and activity to communicate. The docs explain how you should do it. Also, this guy explains in details how you can do it.

signInWithEmailAndPassword from Activity to Fragment

1 Answers