Using Firebase in Android Apps Aljan Porquillo @forceporquillo Software Engineer, Finastra 

History of myself • BS CS Specialized in Software Engineering; FEU Institute of Technology • Currently working for a British financial software • Freelance Android Developer, 2019-present • Open-source contributor (Android, Google, Firebase, Tinder, Telegram, Signal, etc.) • I love building things around Android and the JVM 

• What is Firebase? • Common challenges in Android development • Integrating Firebase in your existing Android app • Authentication – Login user using Email, Facebook, Google • Realtime Database – chat app • Cloud Storage – image upload Agenda 

What is Firebase? 

Google’s mobile application development platform that helps developers build, improve, and grow apps. - Firebase Website 

Suite of tools that enable developers to develop high quality mobile apps 

build, improve, grow 

Evolution of Firebase 2011 2012 2014 2016 2017 Envolve Online chat functionality Realtime Database Introduce Cloud Firestore 2016 Acquired by Auth, Hosting born Founded by James Taplin and Andrew Lee 

• Manage your users in a simple and secure way. • Offers multiple methods to authenticate, including email and password, third-party providers like Google, Facebook, etc. 

• It's an efficient, low-latency solution for mobile apps that require synced states across clients in real-time. • Offline support capability 

• Store and sync data between users and devices - at global scale - using a cloud-hosted, NoSQL database. • Powerful queries • Offline support capability 

• Simplify your web hosting with tools made specifically for modern web apps. 

Backed by Google Cloud Platform Infrastructure 

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Java/Kotlin Objective-C/Swift Native platforms Client SDKs 

Supported platforms Cross-platform Client SDKs 

“It solves all the common mobile App Development challenges” Why Firebase is popular among mobile developers? 

The Challenges in Android Development 

Designed by https://www.behance.net/jeaaanius 

Authentication • Login via email, Facebook, Google. • To store and identify current user state. 

Persistence Data Storage • Store current state of Medicine intake count • Upload documents/images 

How? 

Authentication? Data persistence (offline/online sync)? Improve and Monitor? Grow and Scale? How to handle 

Traditional Android Development 

Android Development with Firebase 

Getting Started 

// See documentation at https://firebase.google.com/docs/auth/android/password-auth fun signInFirebaseWithEmailPassword(email: String, password: String) { Firebase.auth.signInWithEmailAndPassword(email, password) .addOnCompleteListener { if (it.isSuccessful) { navigateToMainScreen() } else { // display error message } } } 

// See documentation at https://developers.google.com/identity/sign-in/android/sign-in // Configure sign-in to request the user's ID, email address, and basic // profile. ID and basic profile are included in DEFAULT_SIGN_IN. private val signInOptions: GoogleSignInOptions by lazy { GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN) .requestIdToken(getString(R.string.default_web_client_id)) .requestEmail() .build() } private val googleSignInContract = registerForActivityResult( ActivityResultContracts.StartActivityForResult() ) { result -> if (result.resultCode != RESULT_OK) { Logger.e("GoogleSignInContract: failed") return@registerForActivityResult } val signInTask = GoogleSignIn.getSignedInAccountFromIntent(result.data) try { val googleSignInAccount = signInTask.getResult(ApiException::class.java) signInFirebaseWithGoogleAccount(googleSignInAccount) } catch (e: ApiException) { // consume error message and display to the user. } } 

fun signInFirebaseWithGoogleAccount(googleSignIn: GoogleSignInAccount) { val credential = GoogleAuthProvider.getCredential(googleSignIn.idToken, null) Firebase.auth.signInWithCredential(credential).addOnCompleteListener { if (it.isSuccessful) { navigateToMainScreen() } else { // display error message } } } // invoke Google sign in button to authenticate with Firebase Auth. binding.signInWithGoogleBtn.setOnClickListener { val signInClient = GoogleSignIn.getClient(requireContext(), signInOptions) googleSignInContract.launch(signInClient.signInIntent) } // See documentation at https://firebase.google.com/docs/auth/android/google-signin 

// See documentation at https://developers.facebook.com/docs/facebook-login/android // CallbackManager manages the callbacks into the FacebookSdk from // an Activity's or Fragment's onActivityResult() method. private val callbackManager = CallbackManager.Factory.create() // Since we are not going to use Facebook’s default Login UI Button, // therefore, we will manually configure our LoginManager logic to our // custom LoginButton UI. private val loginManager by lazy { LoginManager.getInstance().apply { setLoginBehavior(LoginBehavior.DIALOG_ONLY) setAuthType(ServerProtocol.DIALOG_REREQUEST_AUTH_TYPE) registerCallback(callbackManager, facebookCallback) … } } // A callback listener for retrieving Facebook login result private val facebookCallback = object : FacebookCallback { override fun onSuccess(result: LoginResult) { signInFirebaseWithFacebookAccessToken(result.accessToken) } // comment out for abbrev. } 

// Request permission for accessing user email and public profile. val facebookPermissions = listOf("email", "public_profile") // invoke Facebook login button to authenticate with Firebase Auth. binding.signInWithFacebookBtn.setOnClickListener { facebookLoginContract.launch(facebookPermissions) } fun signInFirebaseWithFacebookAccessToken(accessToken: AccessToken) { val credential = FacebookAuthProvider.getCredential(accessToken.token) Firebase.auth.signInWithCredential(credential) .addOnCompleteListener { if (it.isSuccessful) { navigateToMainScreen() } else { // display error message } } } // See documentation at https://firebase.google.com/docs/auth/android/facebook-login