Save phone verification ID across process deaths (#1393)

Author: SUPERCILEX

auth/src/main/java/com/firebase/ui/auth/ui/phone/PhoneActivity.java

@@ -46,6 +46,8 @@
  */
 @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
 public class PhoneActivity extends AppCompatBase {
+    private PhoneNumberVerificationHandler mPhoneVerifier;
+
     public static Intent createIntent(Context context, FlowParameters params, Bundle args) {
         return createBaseIntent(context, PhoneActivity.class, params)
                 .putExtra(ExtraConstants.PARAMS, args);
@@ -72,10 +74,10 @@ protected void onFailure(@NonNull Exception e) {
             }
         });
 
-        final PhoneNumberVerificationHandler phoneVerifier =
-                ViewModelProviders.of(this).get(PhoneNumberVerificationHandler.class);
-        phoneVerifier.init(getFlowParams());
-        phoneVerifier.getOperation().observe(this, new ResourceObserver<PhoneVerification>(
+        mPhoneVerifier = ViewModelProviders.of(this).get(PhoneNumberVerificationHandler.class);
+        mPhoneVerifier.init(getFlowParams());
+        mPhoneVerifier.onRestoreInstanceState(savedInstanceState);
+        mPhoneVerifier.getOperation().observe(this, new ResourceObserver<PhoneVerification>(
                 this, R.string.fui_verifying) {
             @Override
             protected void onSuccess(@NonNull PhoneVerification verification) {
@@ -121,6 +123,12 @@ protected void onFailure(@NonNull Exception e) {
                 .commit();
     }
 
+    @Override
+    protected void onSaveInstanceState(Bundle outState) {
+        super.onSaveInstanceState(outState);
+        mPhoneVerifier.onSaveInstanceState(outState);
+    }
+
     @Override
     public void onBackPressed() {
         if (getSupportFragmentManager().getBackStackEntryCount() > 0) {

auth/src/main/java/com/firebase/ui/auth/ui/phone/PhoneNumberVerificationHandler.java

@@ -1,7 +1,9 @@
 package com.firebase.ui.auth.ui.phone;
 
 import android.app.Application;
+import android.os.Bundle;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 
 import com.firebase.ui.auth.data.model.PhoneNumberVerificationRequiredException;
 import com.firebase.ui.auth.data.model.Resource;
@@ -15,6 +17,7 @@
 
 public class PhoneNumberVerificationHandler extends AuthViewModelBase<PhoneVerification> {
     private static final long AUTO_RETRIEVAL_TIMEOUT_SECONDS = 120;
+    private static final String VERIFICATION_ID_KEY = "verification_id";
 
     private String mVerificationId;
     private PhoneAuthProvider.ForceResendingToken mForceResendingToken;
@@ -60,4 +63,14 @@ public void submitVerificationCode(String number, String code) {
                 PhoneAuthProvider.getCredential(mVerificationId, code),
                 false)));
     }
+
+    public void onSaveInstanceState(@NonNull Bundle outState) {
+        outState.putString(VERIFICATION_ID_KEY, mVerificationId);
+    }
+
+    public void onRestoreInstanceState(@Nullable Bundle savedInstanceState) {
+        if (mVerificationId == null && savedInstanceState != null) {
+            mVerificationId = savedInstanceState.getString(VERIFICATION_ID_KEY);
+        }
+    }
 }