[in_app_purchase] Add play country code api

packages/in_app_purchase/in_app_purchase_android/CHANGELOG.md

@@ -1,5 +1,6 @@
-## NEXT
+## 0.3.0+18
 
+* Adds new getCountryCode() method to InAppPurchaseAndroidPlatformAddition to get a customer's country code.
 * Updates compileSdk version to 34.
 
 ## 0.3.0+17

packages/in_app_purchase/in_app_purchase_android/android/build.gradle

@@ -26,10 +26,11 @@ android {
     if (project.android.hasProperty("namespace")) {
         namespace 'io.flutter.plugins.inapppurchase'
     }
+
     compileSdk 34
 
     defaultConfig {
-        minSdkVersion 16
+        minSdk 19
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
     }
     lintOptions {
@@ -61,7 +62,7 @@ dependencies {
     // org.jetbrains.kotlin:kotlin-bom artifact purpose is to align kotlin stdlib and related code versions.
     // See: https://youtrack.jetbrains.com/issue/KT-55297/kotlin-stdlib-should-declare-constraints-on-kotlin-stdlib-jdk8-and-kotlin-stdlib-jdk7
     implementation(platform("org.jetbrains.kotlin:kotlin-bom:1.8.22"))
-    implementation 'com.android.billingclient:billing:6.0.1'
+    implementation 'com.android.billingclient:billing:6.1.0'
     testImplementation 'junit:junit:4.13.2'
     testImplementation 'org.json:json:20231013'
     testImplementation 'org.mockito:mockito-core:5.4.0'

packages/in_app_purchase/in_app_purchase_android/android/src/main/java/io/flutter/plugins/inapppurchase/MethodCallHandlerImpl.java

@@ -4,6 +4,7 @@
 
 package io.flutter.plugins.inapppurchase;
 
+import static io.flutter.plugins.inapppurchase.Translator.fromBillingConfig;
 import static io.flutter.plugins.inapppurchase.Translator.fromBillingResult;
 import static io.flutter.plugins.inapppurchase.Translator.fromProductDetailsList;
 import static io.flutter.plugins.inapppurchase.Translator.fromPurchaseHistoryRecordList;
@@ -25,6 +26,7 @@
 import com.android.billingclient.api.BillingResult;
 import com.android.billingclient.api.ConsumeParams;
 import com.android.billingclient.api.ConsumeResponseListener;
+import com.android.billingclient.api.GetBillingConfigParams;
 import com.android.billingclient.api.ProductDetails;
 import com.android.billingclient.api.QueryProductDetailsParams;
 import com.android.billingclient.api.QueryProductDetailsParams.Product;
@@ -62,6 +64,7 @@ static final class MethodNames {
         "BillingClient#acknowledgePurchase(AcknowledgePurchaseParams, AcknowledgePurchaseResponseListener)";
     static final String IS_FEATURE_SUPPORTED = "BillingClient#isFeatureSupported(String)";
     static final String GET_CONNECTION_STATE = "BillingClient#getConnectionState()";
+    static final String GET_BILLING_CONFIG = "BillingClient#getBillingConfig()";
 
     private MethodNames() {}
   }
@@ -184,11 +187,22 @@ public void onMethodCall(@NonNull MethodCall call, @NonNull MethodChannel.Result
       case MethodNames.GET_CONNECTION_STATE:
         getConnectionState(result);
         break;
+      case MethodNames.GET_BILLING_CONFIG:
+        getBillingConfig(result);
+        break;
       default:
         result.notImplemented();
     }
   }
 
+  private void getBillingConfig(final MethodChannel.Result result) {
+    billingClient.getBillingConfigAsync(
+        GetBillingConfigParams.newBuilder().build(),
+        (billingResult, billingConfig) -> {
+          result.success(fromBillingConfig(billingResult, billingConfig));
+        });
+  }
+
   private void endConnection(final MethodChannel.Result result) {
     endBillingClientConnection();
     result.success(null);

packages/in_app_purchase/in_app_purchase_android/android/src/main/java/io/flutter/plugins/inapppurchase/Translator.java

@@ -7,6 +7,7 @@
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import com.android.billingclient.api.AccountIdentifiers;
+import com.android.billingclient.api.BillingConfig;
 import com.android.billingclient.api.BillingResult;
 import com.android.billingclient.api.ProductDetails;
 import com.android.billingclient.api.Purchase;
@@ -231,6 +232,14 @@ static HashMap<String, Object> fromBillingResult(BillingResult billingResult) {
     return info;
   }
 
+  /** Converter from {@link BillingResult} and {@link BillingConfig} to map. */
+  static HashMap<String, Object> fromBillingConfig(
+      BillingResult result, BillingConfig billingConfig) {
+    HashMap<String, Object> info = fromBillingResult(result);
+    info.put("countryCode", billingConfig.getCountryCode());
+    return info;
+  }
+
   /**
    * Gets the symbol of for the given currency code for the default {@link Locale.Category#DISPLAY
    * DISPLAY} locale. For example, for the US Dollar, the symbol is "$" if the default locale is the

packages/in_app_purchase/in_app_purchase_android/android/src/test/java/io/flutter/plugins/inapppurchase/MethodCallHandlerTest.java

@@ -7,6 +7,7 @@
 import static io.flutter.plugins.inapppurchase.MethodCallHandlerImpl.MethodNames.ACKNOWLEDGE_PURCHASE;
 import static io.flutter.plugins.inapppurchase.MethodCallHandlerImpl.MethodNames.CONSUME_PURCHASE_ASYNC;
 import static io.flutter.plugins.inapppurchase.MethodCallHandlerImpl.MethodNames.END_CONNECTION;
+import static io.flutter.plugins.inapppurchase.MethodCallHandlerImpl.MethodNames.GET_BILLING_CONFIG;
 import static io.flutter.plugins.inapppurchase.MethodCallHandlerImpl.MethodNames.IS_FEATURE_SUPPORTED;
 import static io.flutter.plugins.inapppurchase.MethodCallHandlerImpl.MethodNames.IS_READY;
 import static io.flutter.plugins.inapppurchase.MethodCallHandlerImpl.MethodNames.LAUNCH_BILLING_FLOW;
@@ -16,6 +17,7 @@
 import static io.flutter.plugins.inapppurchase.MethodCallHandlerImpl.MethodNames.QUERY_PURCHASE_HISTORY_ASYNC;
 import static io.flutter.plugins.inapppurchase.MethodCallHandlerImpl.MethodNames.START_CONNECTION;
 import static io.flutter.plugins.inapppurchase.PluginPurchaseListener.ON_PURCHASES_UPDATED;
+import static io.flutter.plugins.inapppurchase.Translator.fromBillingConfig;
 import static io.flutter.plugins.inapppurchase.Translator.fromBillingResult;
 import static io.flutter.plugins.inapppurchase.Translator.fromProductDetailsList;
 import static io.flutter.plugins.inapppurchase.Translator.fromPurchaseHistoryRecordList;
@@ -46,10 +48,13 @@
 import com.android.billingclient.api.AcknowledgePurchaseResponseListener;
 import com.android.billingclient.api.BillingClient;
 import com.android.billingclient.api.BillingClientStateListener;
+import com.android.billingclient.api.BillingConfig;
+import com.android.billingclient.api.BillingConfigResponseListener;
 import com.android.billingclient.api.BillingFlowParams;
 import com.android.billingclient.api.BillingResult;
 import com.android.billingclient.api.ConsumeParams;
 import com.android.billingclient.api.ConsumeResponseListener;
+import com.android.billingclient.api.GetBillingConfigParams;
 import com.android.billingclient.api.ProductDetails;
 import com.android.billingclient.api.ProductDetailsResponseListener;
 import com.android.billingclient.api.Purchase;
@@ -90,6 +95,7 @@ public class MethodCallHandlerTest {
   @Mock Context context;
   @Mock ActivityPluginBinding mockActivityPluginBinding;
   @Captor ArgumentCaptor<HashMap<String, Object>> resultCaptor;
+  @Mock BillingConfig mockBillingConfig;
 
   @Before
   public void setUp() {
@@ -185,6 +191,35 @@ public void startConnection_multipleCalls() {
     verify(result, times(1)).success(any());
   }
 
+  @Test
+  public void getBillingConfigSuccess() {
+    mockStartConnection();
+    ArgumentCaptor<GetBillingConfigParams> paramsCaptor =
+        ArgumentCaptor.forClass(GetBillingConfigParams.class);
+    ArgumentCaptor<BillingConfigResponseListener> listenerCaptor =
+        ArgumentCaptor.forClass(BillingConfigResponseListener.class);
+    MethodCall billingCall = new MethodCall(GET_BILLING_CONFIG, null);
+    methodChannelHandler.onMethodCall(billingCall, mock(Result.class));
+    BillingResult billingResult =
+        BillingResult.newBuilder()
+            .setResponseCode(100)
+            .setDebugMessage("dummy debug message")
+            .build();
+    final String expectedCountryCode = "US";
+    final HashMap<String, Object> expectedResult = fromBillingResult(billingResult);
+    expectedResult.put("countryCode", expectedCountryCode);
+
+    when(mockBillingConfig.getCountryCode()).thenReturn(expectedCountryCode);
+    doNothing()
+        .when(mockBillingClient)
+        .getBillingConfigAsync(paramsCaptor.capture(), listenerCaptor.capture());
+
+    methodChannelHandler.onMethodCall(billingCall, result);
+    listenerCaptor.getValue().onBillingConfigResponse(billingResult, mockBillingConfig);
+
+    verify(result, times(1)).success(fromBillingConfig(billingResult, mockBillingConfig));
+  }
+
   @Test
   public void endConnection() {
     // Set up a connected BillingClient instance

packages/in_app_purchase/in_app_purchase_android/example/README.md

@@ -7,3 +7,58 @@ package.
 
 Unless you are making changes to this implementation package, this example is
 very unlikely to be relevant.
+
+# In App Purchase Example
+
+### Preparation
+
+There's a significant amount of setup required for testing in-app purchases
+successfully, including registering new app IDs and store entries to use for
+testing in the Play Developer Console. Google Play requires developers to
+configure an app with in-app items for purchase to call their in-app-purchase
+APIs. The Google Play Store has extensive documentation on how to do this, and
+we've also included a high level guide below.
+
+* [Google Play Billing Overview](https://developer.android.com/google/play/billing/billing_overview)
+
+### Android
+
+1. Create a new app in the [Play Developer
+   Console](https://play.google.com/apps/publish/) (PDC).
+
+2. Sign up for a merchant's account in the PDC.
+
+3. Create IAPs in the PDC available for purchase in the app. The example assumes
+   the following SKU IDs exist:
+
+   - `consumable`: A managed product.
+   - `upgrade`: A managed product.
+   - `subscription_silver`: A lower level subscription.
+   - `subscription_gold`: A higher level subscription.
+
+   Make sure that all of the products are set to `ACTIVE`.
+
+4. Update `APP_ID` in `example/android/app/build.gradle` to match your package
+   ID in the PDC.
+
+5. Create an `example/android/keystore.properties` file with all your signing
+   information. `keystore.example.properties` exists as an example to follow.
+   It's impossible to use any of the `BillingClient` APIs from an unsigned APK.
+   See
+   [keystore](https://developer.android.com/studio/publish/app-signing#secure-shared-keystore)
+   and [signing](https://developer.android.com/studio/publish/app-signing#sign-apk) and
+   [flutter-android](https://docs.flutter.dev/deployment/android#signing-the-app)
+   for more information.
+
+6. Build a signed apk. `flutter build apk` will work for this, the gradle files
+   in this project have been configured to sign even debug builds.
+
+7. Upload the signed APK from step 6 to the PDC, and publish that to the alpha
+   test channel. Add your test account as an approved tester. The
+   `BillingClient` APIs won't work unless the app has been fully published to
+   the alpha channel and is being used by an authorized test account. See
+   [here](https://support.google.com/googleplay/android-developer/answer/3131213)
+   for more info.
+
+8. Sign in to the test device with the test account from step #7. Then use
+   `flutter run` to install the app to the device and test like normal.

packages/in_app_purchase/in_app_purchase_android/example/lib/main.dart

@@ -48,6 +48,7 @@ class _MyAppState extends State<_MyApp> {
   List<ProductDetails> _products = <ProductDetails>[];
   List<PurchaseDetails> _purchases = <PurchaseDetails>[];
   List<String> _consumables = <String>[];
+  String _countryCode = '';
   bool _isAvailable = false;
   bool _purchasePending = false;
   bool _loading = true;
@@ -228,6 +229,11 @@ class _MyAppState extends State<_MyApp> {
               'This app needs special configuration to run. Please see example/README.md for instructions.')));
     }
 
+    productList.add(ListTile(
+        title: Text('User Country Code',
+            style: TextStyle(color: ThemeData.light().colorScheme.error)),
+        subtitle: Text(_countryCode)));
+
     // This loading previous purchases code is just a demo. Please do not use this as it is.
     // In your app you should always verify the purchase data using the `verificationData` inside the [PurchaseDetails] object before trusting it.
     // We recommend that you use your own server to verify the purchase data.
@@ -346,6 +352,12 @@ class _MyAppState extends State<_MyApp> {
     });
   }
 
+  Future<void> deliverCountryCode(String countryCode) async {
+    setState(() {
+      _countryCode = countryCode;
+    });
+  }
+
   Future<void> deliverProduct(PurchaseDetails purchaseDetails) async {
     // IMPORTANT!! Always verify purchase details before delivering the product.
     if (purchaseDetails.productID == _kConsumableId) {
@@ -385,6 +397,10 @@ class _MyAppState extends State<_MyApp> {
       if (purchaseDetails.status == PurchaseStatus.pending) {
         showPendingUI();
       } else {
+        final InAppPurchaseAndroidPlatformAddition addition =
+            InAppPurchasePlatformAddition.instance!
+                as InAppPurchaseAndroidPlatformAddition;
+        unawaited(deliverCountryCode(await addition.getCountryCode()));
         if (purchaseDetails.status == PurchaseStatus.error) {
           handleError(purchaseDetails.error!);
         } else if (purchaseDetails.status == PurchaseStatus.purchased ||
@@ -399,10 +415,6 @@ class _MyAppState extends State<_MyApp> {
         }
 
         if (!_kAutoConsume && purchaseDetails.productID == _kConsumableId) {
-          final InAppPurchaseAndroidPlatformAddition addition =
-              InAppPurchasePlatformAddition.instance!
-                  as InAppPurchaseAndroidPlatformAddition;
-
           await addition.consumePurchase(purchaseDetails);
         }
 

packages/in_app_purchase/in_app_purchase_android/lib/src/billing_client_wrappers/billing_client_wrapper.dart

@@ -10,6 +10,7 @@ import 'package:json_annotation/json_annotation.dart';
 
 import '../../billing_client_wrappers.dart';
 import '../channel.dart';
+import 'billing_config_wrapper.dart';
 
 part 'billing_client_wrapper.g.dart';
 
@@ -324,6 +325,21 @@ class BillingClient {
     return result ?? false;
   }
 
+  /// BillingConfig method channel string identifier.
+  //
+  // Must match the value of GET_BILLING_CONFIG in
+  // ../../../android/src/main/java/io/flutter/plugins/inapppurchase/MethodCallHandlerImpl.java
+  @visibleForTesting
+  final String getBillingConfigMethodString =
+      'BillingClient#getBillingConfig()';
+
+  /// Fetches billing config info into a [BillingConfigWrapper] object.
+  Future<BillingConfigWrapper> getBillingConfig() async {
+    return BillingConfigWrapper.fromJson((await channel
+            .invokeMapMethod<String, dynamic>(getBillingConfigMethodString)) ??
+        <String, dynamic>{});
+  }
+
   /// The method call handler for [channel].
   @visibleForTesting
   Future<void> callHandler(MethodCall call) async {

packages/in_app_purchase/in_app_purchase_android/lib/src/billing_client_wrappers/billing_config_wrapper.dart

@@ -0,0 +1,74 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:flutter/material.dart';
+import 'package:json_annotation/json_annotation.dart';
+
+import '../../billing_client_wrappers.dart';
+
+// WARNING: Changes to `@JsonSerializable` classes need to be reflected in the
+// below generated file. Run `flutter packages pub run build_runner watch` to
+// rebuild and watch for further changes.
+part 'billing_config_wrapper.g.dart';
+
+/// The error message shown when the map represents billing config is invalid from method channel.
+///
+/// This usually indicates a serious underlining code issue in the plugin.
+@visibleForTesting
+const String kInvalidBillingConfigErrorMessage =
+    'Invalid billing config map from method channel.';
+
+/// Params containing the response code and the debug message from the Play Billing API response.
+@JsonSerializable()
+@BillingResponseConverter()
+@immutable
+class BillingConfigWrapper implements HasBillingResponse {
+  /// Constructs the object with [responseCode] and [debugMessage].
+  const BillingConfigWrapper(
+      {required this.responseCode, this.debugMessage, this.countryCode = ''});
+
+  /// Constructs an instance of this from a key value map of data.
+  ///
+  /// The map needs to have named string keys with values matching the names and
+  /// types of all of the members on this class.
+  factory BillingConfigWrapper.fromJson(Map<String, dynamic>? map) {
+    if (map == null || map.isEmpty) {
+      return const BillingConfigWrapper(
+        responseCode: BillingResponse.error,
+        debugMessage: kInvalidBillingConfigErrorMessage,
+      );
+    }
+    return _$BillingConfigWrapperFromJson(map);
+  }
+
+  /// Response code returned in the Play Billing API calls.
+  @override
+  final BillingResponse responseCode;
+
+  /// Debug message returned in the Play Billing API calls.
+  ///
+  /// Defaults to `null`.
+  /// This message uses an en-US locale and should not be shown to users.
+  @JsonKey(defaultValue: '')
+  final String? debugMessage;
+
+  /// https://developer.android.com/reference/com/android/billingclient/api/BillingConfig#getCountryCode()
+  @JsonKey(defaultValue: '')
+  final String countryCode;
+
+  @override
+  bool operator ==(Object other) {
+    if (other.runtimeType != runtimeType) {
+      return false;
+    }
+
+    return other is BillingConfigWrapper &&
+        other.responseCode == responseCode &&
+        other.debugMessage == debugMessage &&
+        other.countryCode == countryCode;
+  }
+
+  @override
+  int get hashCode => Object.hash(responseCode, debugMessage, countryCode);
+}