[webview_flutter] Add a method for getting the user agent

packages/webview_flutter/webview_flutter/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 4.3.0
+
+* Adds support to retrieve the user agent. See `WebViewController.getUserAgent`.
+
 ## 4.2.2
 
 * Fixes documentation typo.

packages/webview_flutter/webview_flutter/example/integration_test/webview_flutter_test.dart

@@ -179,7 +179,7 @@ Future<void> main() async {
 
     await pageFinished.future;
 
-    final String customUserAgent = await _getUserAgent(controller);
+    final String? customUserAgent = await controller.getUserAgent();
     expect(customUserAgent, 'Custom_User_Agent1');
   });
 
@@ -876,22 +876,6 @@ String _webViewString(String value) {
   return '"$value"';
 }
 
-/// Returns the value used for the HTTP User-Agent: request header in subsequent HTTP requests.
-Future<String> _getUserAgent(WebViewController controller) async {
-  return _runJavascriptReturningResult(controller, 'navigator.userAgent;');
-}
-
-Future<String> _runJavascriptReturningResult(
-  WebViewController controller,
-  String js,
-) async {
-  if (defaultTargetPlatform == TargetPlatform.iOS) {
-    return await controller.runJavaScriptReturningResult(js) as String;
-  }
-  return jsonDecode(await controller.runJavaScriptReturningResult(js) as String)
-      as String;
-}
-
 class ResizableWebView extends StatefulWidget {
   const ResizableWebView({
     super.key,

packages/webview_flutter/webview_flutter/example/pubspec.yaml

@@ -36,3 +36,8 @@ flutter:
     - assets/sample_video.mp4
     - assets/www/index.html
     - assets/www/styles/style.css
+
+# FOR TESTING AND INITIAL REVIEW ONLY. DO NOT MERGE.
+# See https://github.com/flutter/flutter/wiki/Contributing-to-Plugins-and-Packages#changing-federated-plugins
+dependency_overrides:
+   {webview_flutter_android: {path: ../../../webview_flutter/webview_flutter_android}, webview_flutter_platform_interface: {path: ../../../webview_flutter/webview_flutter_platform_interface}, webview_flutter_wkwebview: {path: ../../../webview_flutter/webview_flutter_wkwebview}}

packages/webview_flutter/webview_flutter/lib/src/webview_controller.dart

@@ -353,6 +353,11 @@ class WebViewController {
   Future<void> setUserAgent(String? userAgent) {
     return platform.setUserAgent(userAgent);
   }
+
+  /// Gets the value used for the HTTP `User-Agent:` request header.
+  Future<String?> getUserAgent() {
+    return platform.getUserAgent();
+  }
 }
 
 /// Permissions request when web content requests access to protected resources.

packages/webview_flutter/webview_flutter/pubspec.yaml

@@ -2,7 +2,7 @@ name: webview_flutter
 description: A Flutter plugin that provides a WebView widget on Android and iOS.
 repository: https://github.com/flutter/packages/tree/main/packages/webview_flutter/webview_flutter
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+webview%22
-version: 4.2.2
+version: 4.3.0
 
 environment:
   sdk: ">=2.18.0 <4.0.0"
@@ -29,3 +29,8 @@ dev_dependencies:
     sdk: flutter
   mockito: 5.4.1
   plugin_platform_interface: ^2.1.3
+
+# FOR TESTING AND INITIAL REVIEW ONLY. DO NOT MERGE.
+# See https://github.com/flutter/flutter/wiki/Contributing-to-Plugins-and-Packages#changing-federated-plugins
+dependency_overrides:
+   {webview_flutter_android: {path: ../../webview_flutter/webview_flutter_android}, webview_flutter_platform_interface: {path: ../../webview_flutter/webview_flutter_platform_interface}, webview_flutter_wkwebview: {path: ../../webview_flutter/webview_flutter_wkwebview}}

packages/webview_flutter/webview_flutter/test/legacy/webview_flutter_test.mocks.dart

@@ -1,7 +1,9 @@
-// Mocks generated by Mockito 5.4.0 from annotations
+// Mocks generated by Mockito 5.4.1 from annotations
 // in webview_flutter/test/legacy/webview_flutter_test.dart.
 // Do not manually edit this file.
 
+// @dart=2.19
+
 // ignore_for_file: no_leading_underscores_for_library_prefixes
 import 'dart:async' as _i9;
 

packages/webview_flutter/webview_flutter/test/navigation_delegate_test.mocks.dart

@@ -1,7 +1,9 @@
-// Mocks generated by Mockito 5.4.0 from annotations
+// Mocks generated by Mockito 5.4.1 from annotations
 // in webview_flutter/test/navigation_delegate_test.dart.
 // Do not manually edit this file.
 
+// @dart=2.19
+
 // ignore_for_file: no_leading_underscores_for_library_prefixes
 import 'dart:async' as _i8;
 
@@ -208,6 +210,16 @@ class MockPlatformNavigationDelegate extends _i1.Mock
         returnValueForMissingStub: _i8.Future<void>.value(),
       ) as _i8.Future<void>);
   @override
+  _i8.Future<void> setOnHttpError(_i3.HttpResponseErrorCallback? onHttpError) =>
+      (super.noSuchMethod(
+        Invocation.method(
+          #setOnHttpError,
+          [onHttpError],
+        ),
+        returnValue: _i8.Future<void>.value(),
+        returnValueForMissingStub: _i8.Future<void>.value(),
+      ) as _i8.Future<void>);
+  @override
   _i8.Future<void> setOnProgress(_i3.ProgressCallback? onProgress) =>
       (super.noSuchMethod(
         Invocation.method(

packages/webview_flutter/webview_flutter/test/webview_controller_test.dart

@@ -387,6 +387,23 @@ void main() {
     requestCallback(const TestPlatformWebViewPermissionRequest());
     expect(permissionRequestCallbackCalled, isTrue);
   });
+
+  test('getUserAgent', () async {
+    final MockPlatformWebViewController mockPlatformWebViewController =
+        MockPlatformWebViewController();
+
+    const String userAgent = 'str';
+
+    when(mockPlatformWebViewController.getUserAgent()).thenAnswer(
+      (_) => Future<String?>.value(userAgent),
+    );
+
+    final WebViewController webViewController = WebViewController.fromPlatform(
+      mockPlatformWebViewController,
+    );
+
+    await expectLater(webViewController.getUserAgent(), completion(userAgent));
+  });
 }
 
 class TestPlatformWebViewPermissionRequest

packages/webview_flutter/webview_flutter/test/webview_controller_test.mocks.dart

@@ -1,7 +1,9 @@
-// Mocks generated by Mockito 5.4.0 from annotations
+// Mocks generated by Mockito 5.4.1 from annotations
 // in webview_flutter/test/webview_controller_test.dart.
 // Do not manually edit this file.
 
+// @dart=2.19
+
 // ignore_for_file: no_leading_underscores_for_library_prefixes
 import 'dart:async' as _i5;
 import 'dart:ui' as _i3;
@@ -353,6 +355,14 @@ class MockPlatformWebViewController extends _i1.Mock
         returnValue: _i5.Future<void>.value(),
         returnValueForMissingStub: _i5.Future<void>.value(),
       ) as _i5.Future<void>);
+  @override
+  _i5.Future<String?> getUserAgent() => (super.noSuchMethod(
+        Invocation.method(
+          #getUserAgent,
+          [],
+        ),
+        returnValue: _i5.Future<String?>.value(),
+      ) as _i5.Future<String?>);
 }
 
 /// A class which mocks [PlatformNavigationDelegate].
@@ -405,6 +415,16 @@ class MockPlatformNavigationDelegate extends _i1.Mock
         returnValueForMissingStub: _i5.Future<void>.value(),
       ) as _i5.Future<void>);
   @override
+  _i5.Future<void> setOnHttpError(_i6.HttpResponseErrorCallback? onHttpError) =>
+      (super.noSuchMethod(
+        Invocation.method(
+          #setOnHttpError,
+          [onHttpError],
+        ),
+        returnValue: _i5.Future<void>.value(),
+        returnValueForMissingStub: _i5.Future<void>.value(),
+      ) as _i5.Future<void>);
+  @override
   _i5.Future<void> setOnProgress(_i6.ProgressCallback? onProgress) =>
       (super.noSuchMethod(
         Invocation.method(

packages/webview_flutter/webview_flutter/test/webview_cookie_manager_test.mocks.dart

@@ -1,7 +1,9 @@
-// Mocks generated by Mockito 5.4.0 from annotations
+// Mocks generated by Mockito 5.4.1 from annotations
 // in webview_flutter/test/webview_cookie_manager_test.dart.
 // Do not manually edit this file.
 
+// @dart=2.19
+
 // ignore_for_file: no_leading_underscores_for_library_prefixes
 import 'dart:async' as _i4;
 

packages/webview_flutter/webview_flutter/test/webview_widget_test.mocks.dart

@@ -1,7 +1,9 @@
-// Mocks generated by Mockito 5.4.0 from annotations
+// Mocks generated by Mockito 5.4.1 from annotations
 // in webview_flutter/test/webview_widget_test.dart.
 // Do not manually edit this file.
 
+// @dart=2.19
+
 // ignore_for_file: no_leading_underscores_for_library_prefixes
 import 'dart:async' as _i7;
 import 'dart:ui' as _i3;
@@ -371,6 +373,14 @@ class MockPlatformWebViewController extends _i1.Mock
         returnValue: _i7.Future<void>.value(),
         returnValueForMissingStub: _i7.Future<void>.value(),
       ) as _i7.Future<void>);
+  @override
+  _i7.Future<String?> getUserAgent() => (super.noSuchMethod(
+        Invocation.method(
+          #getUserAgent,
+          [],
+        ),
+        returnValue: _i7.Future<String?>.value(),
+      ) as _i7.Future<String?>);
 }
 
 /// A class which mocks [PlatformWebViewWidget].

packages/webview_flutter/webview_flutter_android/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 3.10.0
+
+* Adds support for `PlatformWebViewController.getUserAgent`.
+
 ## 3.9.1
 
 * Adjusts SDK checks for better testability.

packages/webview_flutter/webview_flutter_android/android/src/main/java/io/flutter/plugins/webviewflutter/GeneratedAndroidWebView.java

@@ -1607,6 +1607,9 @@ public interface WebSettingsHostApi {
 
     void setTextZoom(@NonNull Long instanceId, @NonNull Long textZoom);
 
+    @NonNull
+    String getUserAgentString(@NonNull Long instanceId);
+
     /** The codec used by WebSettingsHostApi. */
     static @NonNull MessageCodec<Object> getCodec() {
       return new StandardMessageCodec();
@@ -1992,6 +1995,33 @@ static void setup(@NonNull BinaryMessenger binaryMessenger, @Nullable WebSetting
           channel.setMessageHandler(null);
         }
       }
+      {
+        BasicMessageChannel<Object> channel =
+            new BasicMessageChannel<>(
+                binaryMessenger,
+                "dev.flutter.pigeon.WebSettingsHostApi.getUserAgentString",
+                getCodec());
+        if (api != null) {
+          channel.setMessageHandler(
+              (message, reply) -> {
+                ArrayList<Object> wrapped = new ArrayList<Object>();
+                ArrayList<Object> args = (ArrayList<Object>) message;
+                Number instanceIdArg = (Number) args.get(0);
+                try {
+                  String output =
+                      api.getUserAgentString(
+                          (instanceIdArg == null) ? null : instanceIdArg.longValue());
+                  wrapped.add(0, output);
+                } catch (Throwable exception) {
+                  ArrayList<Object> wrappedError = wrapError(exception);
+                  wrapped = wrappedError;
+                }
+                reply.reply(wrapped);
+              });
+        } else {
+          channel.setMessageHandler(null);
+        }
+      }
     }
   }
   /** Generated interface from Pigeon that represents a handler of messages from Flutter. */

packages/webview_flutter/webview_flutter_android/android/src/main/java/io/flutter/plugins/webviewflutter/WebSettingsHostApiImpl.java

@@ -132,4 +132,11 @@ public void setTextZoom(@NonNull Long instanceId, @NonNull Long textZoom) {
     final WebSettings webSettings = Objects.requireNonNull(instanceManager.getInstance(instanceId));
     webSettings.setTextZoom(textZoom.intValue());
   }
+
+  @NonNull
+  @Override
+  public String getUserAgentString(@NonNull Long instanceId) {
+    final WebSettings webSettings = Objects.requireNonNull(instanceManager.getInstance(instanceId));
+    return webSettings.getUserAgentString();
+  }
 }

packages/webview_flutter/webview_flutter_android/android/src/test/java/io/flutter/plugins/webviewflutter/WebSettingsTest.java

@@ -4,6 +4,7 @@
 
 package io.flutter.plugins.webviewflutter;
 
+import static org.junit.Assert.assertEquals;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
@@ -117,4 +118,11 @@ public void setTextZoom() {
     testHostApiImpl.setTextZoom(0L, 100L);
     verify(mockWebSettings).setTextZoom(100);
   }
+
+  @Test
+  public void getUserAgentString() {
+    final String userAgent = "str";
+    when(mockWebSettings.getUserAgentString()).thenReturn(userAgent);
+    assertEquals(testHostApiImpl.getUserAgentString(0L), userAgent);
+  }
 }

packages/webview_flutter/webview_flutter_android/example/integration_test/webview_flutter_test.dart

@@ -342,7 +342,7 @@ Future<void> main() async {
 
     await pageFinished.future;
 
-    final String customUserAgent = await _getUserAgent(controller);
+    final String? customUserAgent = await controller.getUserAgent();
     expect(customUserAgent, 'Custom_User_Agent1');
   });
 
@@ -1228,19 +1228,6 @@ Future<void> main() async {
   );
 }
 
-/// Returns the value used for the HTTP User-Agent: request header in subsequent HTTP requests.
-Future<String> _getUserAgent(PlatformWebViewController controller) async {
-  return _runJavaScriptReturningResult(controller, 'navigator.userAgent;');
-}
-
-Future<String> _runJavaScriptReturningResult(
-  PlatformWebViewController controller,
-  String js,
-) async {
-  return jsonDecode(await controller.runJavaScriptReturningResult(js) as String)
-      as String;
-}
-
 class ResizableWebView extends StatefulWidget {
   const ResizableWebView({
     super.key,

packages/webview_flutter/webview_flutter_android/example/pubspec.yaml

@@ -33,3 +33,8 @@ flutter:
     - assets/sample_video.mp4
     - assets/www/index.html
     - assets/www/styles/style.css
+
+# FOR TESTING AND INITIAL REVIEW ONLY. DO NOT MERGE.
+# See https://github.com/flutter/flutter/wiki/Contributing-to-Plugins-and-Packages#changing-federated-plugins
+dependency_overrides:
+   {webview_flutter_android: {path: ../../../webview_flutter/webview_flutter_android}, webview_flutter_platform_interface: {path: ../../../webview_flutter/webview_flutter_platform_interface}}

packages/webview_flutter/webview_flutter_android/lib/src/android_webview.dart

@@ -694,6 +694,11 @@ class WebSettings extends JavaObject {
     return api.setSetTextZoomFromInstance(this, textZoom);
   }
 
+  /// Gets the WebView's user-agent string.
+  Future<String> getUserAgentString() {
+    return api.getUserAgentStringFromInstance(this);
+  }
+
   @override
   WebSettings copy() {
     return WebSettings.detached(