FirebaseGoogleSignIn

Android Kotlin mini-project where i applied Clean architecture to implement Firebase Google Sign-In.

Steps to set set Firebase

1. Connect Android studio to Firebase app in Firebase console: this can be done after selecting Tools -> firebase -> Authentication -> Authenticate using Google

2. Set the SHA certificate fingerprints key in Firebase console: this key you can get it from signingReport gradle task in the android studio project

   

3. After connection is successful, add the google-services.json file to the project

4. Add Gradle dependencies:

   implementation("com.google.firebase:firebase-auth-ktx:22.3.0")
   implementation("com.google.android.gms:play-services-auth:20.7.0")
   

5. Have an instance of SignInClient:

   private val googleSignInClient by lazy {
        Identity.getSignInClient(applicationContext)
    }
   

6. Prepare the SingIn intent:

   SignInClient.beginSignIn(
            BeginSignInRequest.Builder()
              .setGoogleIdTokenRequestOptions(
                  GoogleIdTokenRequestOptions.builder()
                  .setSupported(true)
                  .setFilterByAuthorizedAccounts(false)
                  .setServerClientId(context.getString(R.string.web_client_id))
                .build()
              )
              .setAutoSelectEnabled(true)
              .build()
        )
   

   where the web_client_id is set under your firebase project -> Authentication -> Sign-in method -> google -> Web SDK configuration

7. Once we receive intent as response, we actually signin:

    val credential = SignInClient?.getSignInCredentialFromIntent(intent)
    val googleIdToken = credential?.googleIdToken
    val googleCredentials = GoogleAuthProvider.getCredential(googleIdToken, null)
    ...
    val user = auth.signInWithCredential(googleCredentials).await().user
    ...
   

No user should be connected using google account, bear in mind that at least you should have a connected google account in the device.