Firebase Google Sign In Authentication Jetpack Compose

In this tutorial we will learn to integrate Google Sign In authentication using firebase. We are using Android Studio Koala latest version at the time of writing this tutorial to use firebase and Google signing method we need to add some dependency.

Steps:

1. Create Android Project

2. Add dependency

3. Create Firebase Project and add firebase with android app

4. Enable Goggle authentication

5. Design you Google signing Screen (Google SignInScreen)

6. MainActivity

How to add dependency?

We can directly add the dependency but it is a little different as we do with older version of android studio.

Lets see how we add in the latest version of Android Studio Iguana

Step 1- Go to build.gradle.kts(Module :app)

(A) Add in

plugins {

id("com.google.gms.google-services")

}

(B) Add in

dependencies{

implementation(libs.firebase.auth)

implementation(libs.androidx.navigation.compose)

}

build.gradle.kts(Module: app)


plugins {
    alias(libs.plugins.androidApplication)
    alias(libs.plugins.jetbrainsKotlinAndroid)
    id("com.google.gms.google-services")
}

android {
    namespace = "com.codingbihar.firebaseproject"
    compileSdk = 34
    defaultConfig {
        applicationId = "com.codingbihar.firebaseproject"
        minSdk = 26
        targetSdk = 34
        versionCode = 1
        versionName = "1.0"

        testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
        vectorDrawables {
            useSupportLibrary = true
        }
    }

    buildTypes {
        release {
            isMinifyEnabled = false
            proguardFiles(
                getDefaultProguardFile("proguard-android-optimize.txt"),
                "proguard-rules.pro"
            )
        }
    }
    compileOptions {
        sourceCompatibility = JavaVersion.VERSION_1_8
        targetCompatibility = JavaVersion.VERSION_1_8
    }
    kotlinOptions {
        jvmTarget = "1.8"
    }
    buildFeatures {
        compose = true
    }
    composeOptions {
        kotlinCompilerExtensionVersion = "1.5.1"
    }
    packaging {
        resources {
            excludes += "/META-INF/{AL2.0,LGPL2.1}"
        }
    }
}

dependencies {

    implementation(libs.androidx.core.ktx)
    implementation(libs.androidx.lifecycle.runtime.ktx)
    implementation(libs.androidx.activity.compose)
    implementation(platform(libs.androidx.compose.bom))
    implementation(libs.androidx.ui)
    implementation(libs.androidx.ui.graphics)
    implementation(libs.androidx.ui.tooling.preview)
    implementation(libs.androidx.material3)
    implementation(libs.androidx.navigation.compose)
    implementation(libs.firebase.auth)
    implementation(libs.play.services.auth)
    testImplementation(libs.junit)
    androidTestImplementation(libs.androidx.junit)
    androidTestImplementation(libs.androidx.espresso.core)
    androidTestImplementation(platform(libs.androidx.compose.bom))
    androidTestImplementation(libs.androidx.ui.test.junit4)
    debugImplementation(libs.androidx.ui.tooling)
    debugImplementation(libs.androidx.ui.test.manifest)
}

Step 2- Go to libs.versions.toml(Version Catalog) here we add versions and libraries

(A) In the [versions] section add

googleServices = "4.4.1"

firebaseAuth = "22.3.1"

navigationCompose = "2.7.7"

(B) In [libraries] section add the following

google-services = { group = "com.google.gms", name = "google-services", version.ref = "googleServices" }

firebase-auth = { group = "com.google.firebase", name = "firebase-auth", version.ref = "firebaseAuth" }

androidx-navigation-compose = { group = "androidx.navigation", name = "navigation-compose", version.ref = "navigationCompose" }

libs.versions.toml(Version Catalog)


[versions]
agp = "8.3.2"
kotlin = "1.9.0"
coreKtx = "1.12.0"
junit = "4.13.2"
junitVersion = "1.1.5"
espressoCore = "3.5.1"
lifecycleRuntimeKtx = "2.7.0"
activityCompose = "1.8.2"
composeBom = "2024.04.00"
googleServices = "4.4.1"
playServicesAuth = "21.0.0"
firebaseAuth = "22.3.1"
navigationCompose = "2.7.7"

[libraries]
androidx-core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "coreKtx" }
junit = { group = "junit", name = "junit", version.ref = "junit" }
play-services-auth = { group = "com.google.android.gms", name = "play-services-auth", version.ref = "playServicesAuth" }
androidx-junit = { group = "androidx.test.ext", name = "junit", version.ref = "junitVersion" }
androidx-espresso-core = { group = "androidx.test.espresso", name = "espresso-core", version.ref = "espressoCore" }
androidx-lifecycle-runtime-ktx = { group = "androidx.lifecycle", name = "lifecycle-runtime-ktx", version.ref = "lifecycleRuntimeKtx" }
androidx-activity-compose = { group = "androidx.activity", name = "activity-compose", version.ref = "activityCompose" }
androidx-compose-bom = { group = "androidx.compose", name = "compose-bom", version.ref = "composeBom" }
androidx-ui = { group = "androidx.compose.ui", name = "ui" }
androidx-ui-graphics = { group = "androidx.compose.ui", name = "ui-graphics" }
androidx-ui-tooling = { group = "androidx.compose.ui", name = "ui-tooling" }
androidx-ui-tooling-preview = { group = "androidx.compose.ui", name = "ui-tooling-preview" }
androidx-ui-test-manifest = { group = "androidx.compose.ui", name = "ui-test-manifest" }
androidx-ui-test-junit4 = { group = "androidx.compose.ui", name = "ui-test-junit4" }
androidx-material3 = { group = "androidx.compose.material3", name = "material3" }
google-services = { group = "com.google.gms", name = "google-services", version.ref = "googleServices" }
firebase-auth = { group = "com.google.firebase", name = "firebase-auth", version.ref = "firebaseAuth" }
androidx-navigation-compose = { group = "androidx.navigation", name = "navigation-compose", version.ref = "navigationCompose" }

[plugins]
androidApplication = { id = "com.android.application", version.ref = "agp" }
jetbrainsKotlinAndroid = { id = "org.jetbrains.kotlin.android", version.ref = "kotlin" }

Add firebase with Android App

Go to firebase console and login by using the email which you use to sign in with android studio

Create a new project with a name as you want

Go to firebase official website and go to the Console

Create a Project with a name here it is Firebase Project

Click the check box and then continue button

Click on Create project button (No need to enable Google analytic to this project in my case)

Press on Continue this is our project is created

Click on Android logo and Register app

Now enter the Name, package name and SHA1

No need to add SDK click on Next step

Download google-services.json file we will use this in our android app and click Next and continue to console.

Go to authentication Get started and enable Google authentication on clicking Google (No need to enable

How to Add google-services.json file

By default project is in Android View click om Android and select Project

Copy the google-services.json and paste it by right click on app and add clint_id from google-services.json in string also

<resources>
    <string name="app_name">Firebase Project</string>
    <string name="default_web_client_id">568467537274-q87d4fhj5nbqpc29r6o2.apps

.googleusercontent.com</string>

</resources>

Copy the google-services.json and paste it by right click on app

How to find the SHA1 key for our APK

Go to Gradle > Task > android > signing report and press enter key

Select app:signingReport and press enter key

If you don't find signing report

1. Click on Build Tool Settings and

2. Go to Gradle Settings.. and

3. Click on Experimental at the bottom and check the box as the fig and

4. Sync Project with Gradle Files wait an few seconds now you are able to see use gradle app:signingReport to get SHA1

MainActivity

Copy this code →


import ...          
          
class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            FirebaseProjectTheme {
                // A surface container using the 'background' color from the theme
                Surface(
                    modifier = Modifier.fillMaxSize(),
                    color = MaterialTheme.colorScheme.background
                ) {
                    GoogleSignInScreen()
                    
                }
            }
        }
    }
}

Google SignInScreen

Copy this code →


import ...

@Composable
fun GoogleSignInScreen() {
    Column(
        Modifier.fillMaxSize(),
        verticalArrangement = Arrangement.Center,
        horizontalAlignment = Alignment.CenterHorizontally
    ) {
        var user by remember { mutableStateOf(Firebase.auth.currentUser) }
        val launcher = rememberFirebaseAuthLauncher(
            onAuthComplete = { result ->
                user = result.user
            },
            onAuthError = {
                user = null
            }
        )
        val token = stringResource(R.string.default_web_client_id)
        val context = LocalContext.current
        Column {
            if (user == null) {
                Text("Not logged in")
                Button(onClick = {
                    val gso =
                        GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
                            .requestIdToken(token)
                            .requestEmail()
                            .build()
                    val googleSignInClient = GoogleSignIn.getClient(context, gso)
                    launcher.launch(googleSignInClient.signInIntent)
                }) {
                    Text(text = "google")
                }
            }
            else {
                Text("Welcome ${user!!.displayName}")
                Button(onClick = {
                    Firebase.auth.signOut()
                    user = null
                }) {
                    Text("Sign out")
                }
            }
        }
    }
}

@Composable
fun rememberFirebaseAuthLauncher(
    onAuthComplete: (AuthResult) -> Unit,
    onAuthError: (ApiException) -> Unit
): ManagedActivityResultLauncher {
    val scope = rememberCoroutineScope()
    return rememberLauncherForActivityResult(ActivityResultContracts.StartActivityForResult()) { result ->
        val task = GoogleSignIn.getSignedInAccountFromIntent(result.data)
        try {
            val account = task.getResult(ApiException::class.java)!!
            val credential = GoogleAuthProvider.getCredential(account.idToken!!, null)
            scope.launch {
                val authResult = Firebase.auth.signInWithCredential(credential).await()
                onAuthComplete(authResult)
            }
        } catch (e: ApiException) {
            onAuthError(e)
        }
    }
}

OUTPUT:

Coding Bihar

Firebase Google Sign In Authentication Jetpack Compose