Update docs with Google's SignIn

mythz · mythz · commit f5e148523bd3 · 2017-03-27T04:19:28.000-04:00
diff --git a/README.md b/README.md
@@ -175,6 +175,7 @@ respective installation guides:
 
  - [Install Twitter SDK](https://fabric.io/kits/android/twitterkit/install)
  - [Install Facebook SDK](https://developers.facebook.com/docs/android/getting-started#androidstudio)
+ - [Install Google SDK](https://developers.google.com/identity/sign-in/android/sign-in)
 
 ### Login Activities
 
@@ -216,7 +217,7 @@ it will load the `LoginButtonsActivity`:
 
 ![](https://raw.githubusercontent.com/ServiceStack/docs/master/docs/images/java/java-android-login-buttons.png)
 
-Where we just use Twitter's and Facebook's Login Button widgets to render the UI in 
+Where we just use Twitter's, Facebook's and Google's Login Button widgets to render the UI in 
 [login_buttons.xml](https://github.com/ServiceStackApps/AndroidJavaChat/blob/master/src/androidchat/app/src/main/res/layout/login_buttons.xml):
 
 ```xml
@@ -233,6 +234,11 @@ Where we just use Twitter's and Facebook's Login Button widgets to render the UI
     android:layout_marginTop="30dp"
     android:layout_marginBottom="30dp" />
 
+<com.google.android.gms.common.SignInButton
+    android:id="@+id/sign_in_button"
+    android:layout_width="wrap_content"
+    android:layout_height="wrap_content" />
+
 <Button
     android:text="Guest Login"
     android:layout_width="wrap_content"
@@ -324,6 +330,9 @@ protected void onActivityResult(int requestCode, int resultCode, Intent data) {
     super.onActivityResult(requestCode, resultCode, data);
     btnTwitterLogin.onActivityResult(requestCode, resultCode, data);
     facebookCallback.onActivityResult(requestCode, resultCode, data);
+    if (requestCode == RC_SIGN_IN) {
+        handleGoogleSignInResult(Auth.GoogleSignInApi.getSignInResultFromIntent(data));
+    }
 }
 ```
 
@@ -384,6 +393,114 @@ The Authentication request to our Chat Server is similar to Twitter's except we
 AccessToken to Authenticate with the Server and we don't need to explicitly save the User's Access Token
 as Facebook's SDK does this for us behind the scenes.
 
+### Signing in with Google SignIn Button
+
+Whilst the sign-in process is similar, Google SignIn requires a lot more effort to setup and leaves you
+to implement a lot of the mechanics yourself starting with having to choose an arbitrary Request Code
+which you'll need to use to manually check whether the Google SignIn Activity has completed, this can
+be any number, e.g:
+
+```java
+private static final int RC_SIGN_IN = 9001; //Arbitrary Request Code
+```
+
+Then you'll need to configure your preferred `GoogleSignInOptions`, as we want to be able to retrieve the
+AccessToken we need to popoulate `requestServerAuthCode()` with our Google OAuth App Id:
+
+> If you don't have a Google App, one can be created at [console.developers.google.com/apis/credentials](https://console.developers.google.com/apis/credentials)
+
+```java
+SignInButton btnGoogleSignIn = (SignInButton) findViewById(R.id.sign_in_button);
+GoogleSignInOptions gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
+    .requestEmail()
+    .requestServerAuthCode(getResources().getString(R.string.google_key))
+    .build();
+googleApiClient = new GoogleApiClient.Builder(this)
+    .enableAutoManage(this, r -> { /* Handle On Connection Failed...*/ })
+    .addApi(Auth.GOOGLE_SIGN_IN_API, gso)
+    .build();
+btnGoogleSignIn.setOnClickListener(v -> {
+    Intent signInIntent = Auth.GoogleSignInApi.getSignInIntent(googleApiClient);
+    startActivityForResult(signInIntent, RC_SIGN_IN);
+});
+```
+
+You'll then need to configure a `GoogleApiClient` with your SignIn Options and then manually bind 
+Google's `SignInButton` to launch a new SignIn Intent with our custom `RC_SIGN_IN`.
+
+Once the User has authorized with Google we're notified in `onActivityResult()` which gets called back
+with our custom `RC_SIGN_IN` to let us know we can process the Google SignIn Result:
+
+```java
+@Override
+protected void onActivityResult(int requestCode, int resultCode, Intent data) {
+    //...
+    if (requestCode == RC_SIGN_IN) {
+        handleGoogleSignInResult(Auth.GoogleSignInApi.getSignInResultFromIntent(data));
+    }
+}
+```
+
+If the `GoogleSignInResult` was successful the User has Signed in locally to our App at that point but 
+as we need to Authenticate the User with the Chat Server we need to retrieve their AccessToken. 
+Unfortunately Google only returns us a Server Auth Code which we need to use to call another Google API,
+passing in our OAuth App Secret to get the User's AccessToken for our App:
+
+```java
+private void handleGoogleSignInResult(GoogleSignInResult result) {
+    if (result.isSuccess()) {
+        GoogleSignInAccount acct = result.getSignInAccount();
+        UiHelpers.setStatus(txtStatus, "Local google sign-in successful, signing into server...");
+
+        Activity activity = this;
+        OkHttpClient client = new OkHttpClient();
+        RequestBody requestBody = new FormBody.Builder()
+            .add("grant_type", "authorization_code")
+            .add("client_id", getResources().getString(R.string.google_key))
+            .add("client_secret", getResources().getString(R.string.google_secret))
+            .add("redirect_uri","")
+            .add("code", acct.getServerAuthCode())
+            .build();
+        Request request = new Request.Builder()
+            .url("https://www.googleapis.com/oauth2/v4/token")
+            .post(requestBody)
+            .build();
+        client.newCall(request).enqueue(new okhttp3.Callback() {
+            @Override
+            public void onFailure(Call call, IOException e) {
+                UiHelpers.setStatus(txtStatus, "Failed to retrieve AccessToken from Google");
+            }
+
+            @Override
+            public void onResponse(Call call, Response response) throws IOException {
+                String json = response.body().string();
+                JsonObject obj = JsonUtils.toJsonObject(json);                
+                String accessToken = obj.get("access_token").getAsString();
+
+                App.get().saveGoogleAccessToken(accessToken);
+                App.get().getServiceClient().postAsync(new dtos.Authenticate()
+                    .setProvider("GoogleOAuth")
+                    .setAccessToken(accessToken)
+                    .setRememberMe(true),
+                    r -> {
+                        UiHelpers.setStatus(txtStatus, "Server google sign-in successful, opening chat...");
+                        stopProgressBar();
+                        startActivity(new Intent(activity, MainActivity.class));
+                    },
+                    error -> {
+                        UiHelpers.setStatusError(txtStatus, "Server google sign-in failed", error);
+                        stopProgressBar();
+                    });
+            }
+        });
+    }
+}
+```
+
+Once we retrieve the `accessToken` the process is similar to our Twitter login where we save the AccessToken
+to allow auto-SignIn's on App Restarts, we then use the `accessToken` to Authenticate with the Chat Server
+then load the `MainActivity` to establish our Authenticated Server Events connection.
+
 ### Anonymous Sign In
 
 If the User doesn't have a Twitter or Facebook account we also let them login as a guest by skipping 
diff --git a/src/androidchat/app/src/main/java/servicestack/net/androidchat/LoginButtonsActivity.java b/src/androidchat/app/src/main/java/servicestack/net/androidchat/LoginButtonsActivity.java
@@ -214,16 +214,16 @@ private void handleGoogleSignInResult(GoogleSignInResult result) {
             Activity activity = this;
             OkHttpClient client = new OkHttpClient();
             RequestBody requestBody = new FormBody.Builder()
-                .add("grant_type", "authorization_code")
-                .add("client_id", getResources().getString(R.string.google_key))
-                .add("client_secret", getResources().getString(R.string.google_secret))
-                .add("redirect_uri","")
-                .add("code", acct.getServerAuthCode())
-                .build();
+                    .add("grant_type", "authorization_code")
+                    .add("client_id", getResources().getString(R.string.google_key))
+                    .add("client_secret", getResources().getString(R.string.google_secret))
+                    .add("redirect_uri","")
+                    .add("code", acct.getServerAuthCode())
+                    .build();
             Request request = new Request.Builder()
-                .url("https://www.googleapis.com/oauth2/v4/token")
-                .post(requestBody)
-                .build();
+                    .url("https://www.googleapis.com/oauth2/v4/token")
+                    .post(requestBody)
+                    .build();
             client.newCall(request).enqueue(new okhttp3.Callback() {
                 @Override
                 public void onFailure(Call call, IOException e) {
@@ -235,22 +235,21 @@ public void onResponse(Call call, Response response) throws IOException {
                     String json = response.body().string();
                     JsonObject obj = JsonUtils.toJsonObject(json);
                     String accessToken = obj.get("access_token").getAsString();
-                    App.get().saveGoogleAccessToken(accessToken);
 
+                    App.get().saveGoogleAccessToken(accessToken);
                     App.get().getServiceClient().postAsync(new dtos.Authenticate()
-                        .setProvider("GoogleOAuth")
-                        .setAccessToken(accessToken)
-                        .setRememberMe(true),
-                        r -> {
-                            UiHelpers.setStatus(txtStatus, "Server google sign-in successful, opening chat...");
-                            Intent intent = new Intent(activity, MainActivity.class);
-                            stopProgressBar();
-                            startActivity(intent);
-                        },
-                        error -> {
-                            UiHelpers.setStatusError(txtStatus, "Server google sign-in failed", error);
-                            stopProgressBar();
-                        });
+                                    .setProvider("GoogleOAuth")
+                                    .setAccessToken(accessToken)
+                                    .setRememberMe(true),
+                            r -> {
+                                UiHelpers.setStatus(txtStatus, "Server google sign-in successful, opening chat...");
+                                stopProgressBar();
+                                startActivity(new Intent(activity, MainActivity.class));
+                            },
+                            error -> {
+                                UiHelpers.setStatusError(txtStatus, "Server google sign-in failed", error);
+                                stopProgressBar();
+                            });
                 }
             });
         }
