[webview_flutter] Add loadRequest functionality to app facing package.

packages/webview_flutter/webview_flutter/README.md

@@ -92,3 +92,8 @@ android {
 
 To use Material Components when the user interacts with input elements in the WebView,
 follow the steps described in the [Enabling Material Components instructions](https://flutter.dev/docs/deployment/android#enabling-material-components).
+
+### Setting custom headers on POST requests
+
+Currently, setting custom headers when making a post request with the WebViewController's `loadRequest` method is not supported on Android.
+If you require this functionality, a workaround is to make the request manually, and then load the response data using `loadHTMLString` instead. 

packages/webview_flutter/webview_flutter/example/lib/main.dart

@@ -7,6 +7,7 @@
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
+import 'dart:typed_data';
 
 import 'package:flutter/material.dart';
 import 'package:webview_flutter/webview_flutter.dart';
@@ -133,6 +134,7 @@ enum MenuOptions {
   listCache,
   clearCache,
   navigationDelegate,
+  doPostRequest,
 }
 
 class SampleMenu extends StatelessWidget {
@@ -171,6 +173,9 @@ class SampleMenu extends StatelessWidget {
               case MenuOptions.navigationDelegate:
                 _onNavigationDelegateExample(controller.data!, context);
                 break;
+              case MenuOptions.doPostRequest:
+                _onDoPostRequest(controller.data!, context);
+                break;
             }
           },
           itemBuilder: (BuildContext context) => <PopupMenuItem<MenuOptions>>[
@@ -203,6 +208,10 @@ class SampleMenu extends StatelessWidget {
               value: MenuOptions.navigationDelegate,
               child: Text('Navigation Delegate example'),
             ),
+            const PopupMenuItem<MenuOptions>(
+              value: MenuOptions.doPostRequest,
+              child: Text('Post Request'),
+            ),
           ],
         );
       },
@@ -279,6 +288,17 @@ class SampleMenu extends StatelessWidget {
     await controller.loadUrl('data:text/html;base64,$contentBase64');
   }
 
+  Future<void> _onDoPostRequest(
+      WebViewController controller, BuildContext context) async {
+    final WebViewRequest request = WebViewRequest(
+      uri: Uri.parse('https://httpbin.org/post'),
+      method: WebViewRequestMethod.post,
+      headers: <String, String>{'foo': 'bar', 'Content-Type': 'text/plain'},
+      body: Uint8List.fromList('Test Body'.codeUnits),
+    );
+    await controller.loadRequest(request);
+  }
+
   Widget _getCookieList(String cookies) {
     if (cookies == null || cookies == '""') {
       return Container();

packages/webview_flutter/webview_flutter/lib/platform_interface.dart

@@ -21,4 +21,6 @@ export 'package:webview_flutter_platform_interface/webview_flutter_platform_inte
         WebSetting,
         WebSettings,
         WebResourceError,
-        WebResourceErrorType;
+        WebResourceErrorType,
+        WebViewRequest,
+        WebViewRequestMethod;

packages/webview_flutter/webview_flutter/lib/src/webview.dart

@@ -513,6 +513,26 @@ class WebViewController {
     return _webViewPlatformController.loadUrl(url, headers);
   }
 
+  /// Makes a specific HTTP request ands loads the response in the webview.
+  ///
+  /// [WebViewRequest.method] must be one of the supported HTTP methods
+  /// in [WebViewRequestMethod].
+  ///
+  /// If [WebViewRequest.headers] is not empty, its key-value pairs will be
+  /// added as the headers for the request.
+  ///
+  /// If [WebViewRequest.body] is not null, it will be added as the body
+  /// for the request.
+  ///
+  /// Throws an ArgumentError if [WebViewRequest.uri] has empty scheme.
+  ///
+  /// Android only:
+  /// When making a POST request, headers are ignored. As a workaround, make
+  /// the request manually and load the response data using [loadHTMLString].
+  Future<void> loadRequest(WebViewRequest request) async {
+    return _webViewPlatformController.loadRequest(request);
+  }
+
   /// Accessor to the current URL that the WebView is displaying.
   ///
   /// If [WebView.initialUrl] was never specified, returns `null`.

packages/webview_flutter/webview_flutter/pubspec.yaml

@@ -19,6 +19,7 @@ flutter:
 dependencies:
   flutter:
     sdk: flutter
+# TODO(BeMacized): Update dependency once it has been merged and published (#4563)
   webview_flutter_android: ^2.3.1
   webview_flutter_platform_interface: ^1.5.2
   webview_flutter_wkwebview: ^2.4.0

packages/webview_flutter/webview_flutter/test/webview_flutter_test.dart

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'dart:typed_data';
+
 import 'package:flutter/src/foundation/basic_types.dart';
 import 'package:flutter/src/gestures/recognizer.dart';
 import 'package:flutter/widgets.dart';
@@ -154,6 +156,29 @@ void main() {
     ));
   });
 
+  testWidgets('loadRequest', (WidgetTester tester) async {
+    WebViewController? controller;
+    await tester.pumpWidget(
+      WebView(
+        onWebViewCreated: (WebViewController webViewController) {
+          controller = webViewController;
+        },
+      ),
+    );
+    expect(controller, isNotNull);
+
+    final WebViewRequest req = WebViewRequest(
+      uri: Uri.parse('https://flutter.dev'),
+      method: WebViewRequestMethod.post,
+      headers: <String, String>{'foo': 'bar'},
+      body: Uint8List.fromList('Test Body'.codeUnits),
+    );
+
+    await controller!.loadRequest(req);
+
+    verify(mockWebViewPlatformController.loadRequest(req));
+  });
+
   testWidgets('Clear Cache', (WidgetTester tester) async {
     WebViewController? controller;
     await tester.pumpWidget(

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

@@ -8,19 +8,19 @@
 
 import 'dart:async' as _i9;
 
-import 'package:flutter/foundation.dart' as _i7;
+import 'package:flutter/foundation.dart' as _i3;
 import 'package:flutter/gestures.dart' as _i8;
 import 'package:flutter/widgets.dart' as _i2;
 import 'package:mockito/mockito.dart' as _i1;
 import 'package:webview_flutter_platform_interface/src/platform_interface/javascript_channel_registry.dart'
-    as _i6;
+    as _i7;
 import 'package:webview_flutter_platform_interface/src/platform_interface/webview_platform.dart'
-    as _i3;
+    as _i4;
 import 'package:webview_flutter_platform_interface/src/platform_interface/webview_platform_callbacks_handler.dart'
-    as _i5;
+    as _i6;
 import 'package:webview_flutter_platform_interface/src/platform_interface/webview_platform_controller.dart'
     as _i10;
-import 'package:webview_flutter_platform_interface/src/types/types.dart' as _i4;
+import 'package:webview_flutter_platform_interface/src/types/types.dart' as _i5;
 
 // ignore_for_file: avoid_redundant_argument_values
 // ignore_for_file: avoid_setters_without_getters
@@ -33,26 +33,26 @@ import 'package:webview_flutter_platform_interface/src/types/types.dart' as _i4;
 
 class _FakeWidget_0 extends _i1.Fake implements _i2.Widget {
   @override
-  String toString({_i2.DiagnosticLevel? minLevel = _i2.DiagnosticLevel.info}) =>
+  String toString({_i3.DiagnosticLevel? minLevel = _i3.DiagnosticLevel.info}) =>
       super.toString();
 }
 
 /// A class which mocks [WebViewPlatform].
 ///
 /// See the documentation for Mockito's code generation for more information.
-class MockWebViewPlatform extends _i1.Mock implements _i3.WebViewPlatform {
+class MockWebViewPlatform extends _i1.Mock implements _i4.WebViewPlatform {
   MockWebViewPlatform() {
     _i1.throwOnMissingStub(this);
   }
 
   @override
   _i2.Widget build(
           {_i2.BuildContext? context,
-          _i4.CreationParams? creationParams,
-          _i5.WebViewPlatformCallbacksHandler? webViewPlatformCallbacksHandler,
-          _i6.JavascriptChannelRegistry? javascriptChannelRegistry,
-          _i3.WebViewPlatformCreatedCallback? onWebViewPlatformCreated,
-          Set<_i7.Factory<_i8.OneSequenceGestureRecognizer>>?
+          _i5.CreationParams? creationParams,
+          _i6.WebViewPlatformCallbacksHandler? webViewPlatformCallbacksHandler,
+          _i7.JavascriptChannelRegistry? javascriptChannelRegistry,
+          _i4.WebViewPlatformCreatedCallback? onWebViewPlatformCreated,
+          Set<_i3.Factory<_i8.OneSequenceGestureRecognizer>>?
               gestureRecognizers}) =>
       (super.noSuchMethod(
           Invocation.method(#build, [], {
@@ -81,13 +81,29 @@ class MockWebViewPlatformController extends _i1.Mock
     _i1.throwOnMissingStub(this);
   }
 
+  @override
+  _i9.Future<void> loadFile(String? absoluteFilePath) =>
+      (super.noSuchMethod(Invocation.method(#loadFile, [absoluteFilePath]),
+          returnValue: Future<void>.value(),
+          returnValueForMissingStub: Future<void>.value()) as _i9.Future<void>);
+  @override
+  _i9.Future<void> loadHtmlString(String? html, {String? baseUrl}) =>
+      (super.noSuchMethod(
+          Invocation.method(#loadHtmlString, [html], {#baseUrl: baseUrl}),
+          returnValue: Future<void>.value(),
+          returnValueForMissingStub: Future<void>.value()) as _i9.Future<void>);
   @override
   _i9.Future<void> loadUrl(String? url, Map<String, String>? headers) =>
       (super.noSuchMethod(Invocation.method(#loadUrl, [url, headers]),
           returnValue: Future<void>.value(),
           returnValueForMissingStub: Future<void>.value()) as _i9.Future<void>);
   @override
-  _i9.Future<void> updateSettings(_i4.WebSettings? setting) =>
+  _i9.Future<void> loadRequest(_i5.WebViewRequest? request) =>
+      (super.noSuchMethod(Invocation.method(#loadRequest, [request]),
+          returnValue: Future<void>.value(),
+          returnValueForMissingStub: Future<void>.value()) as _i9.Future<void>);
+  @override
+  _i9.Future<void> updateSettings(_i5.WebSettings? setting) =>
       (super.noSuchMethod(Invocation.method(#updateSettings, [setting]),
           returnValue: Future<void>.value(),
           returnValueForMissingStub: Future<void>.value()) as _i9.Future<void>);

packages/webview_flutter/webview_flutter_android/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 2.5.0
+
+* Adds support for the `loadRequest` method from the platform interface.
+
 ## 2.4.0
 
 * Adds support for Android's `WebView.loadData` and `WebView.loadDataWithBaseUrl` methods and implements the `loadFile` and `loadHtmlString` methods from the platform interface.

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

@@ -185,6 +185,8 @@ void loadDataWithBaseUrl(
 
     void loadUrl(Long instanceId, String url, Map<String, String> headers);
 
+    void postUrl(Long instanceId, String url, byte[] data);
+
     String getUrl(Long instanceId);
 
     Boolean canGoBack(Long instanceId);
@@ -407,6 +409,39 @@ static void setup(BinaryMessenger binaryMessenger, WebViewHostApi api) {
           channel.setMessageHandler(null);
         }
       }
+      {
+        BasicMessageChannel<Object> channel =
+            new BasicMessageChannel<>(
+                binaryMessenger, "dev.flutter.pigeon.WebViewHostApi.postUrl", getCodec());
+        if (api != null) {
+          channel.setMessageHandler(
+              (message, reply) -> {
+                Map<String, Object> wrapped = new HashMap<>();
+                try {
+                  ArrayList<Object> args = (ArrayList<Object>) message;
+                  Number instanceIdArg = (Number) args.get(0);
+                  if (instanceIdArg == null) {
+                    throw new NullPointerException("instanceIdArg unexpectedly null.");
+                  }
+                  String urlArg = (String) args.get(1);
+                  if (urlArg == null) {
+                    throw new NullPointerException("urlArg unexpectedly null.");
+                  }
+                  byte[] dataArg = (byte[]) args.get(2);
+                  if (dataArg == null) {
+                    throw new NullPointerException("dataArg unexpectedly null.");
+                  }
+                  api.postUrl(instanceIdArg.longValue(), urlArg, dataArg);
+                  wrapped.put("result", null);
+                } catch (Error | RuntimeException exception) {
+                  wrapped.put("error", wrapError(exception));
+                }
+                reply.reply(wrapped);
+              });
+        } else {
+          channel.setMessageHandler(null);
+        }
+      }
       {
         BasicMessageChannel<Object> channel =
             new BasicMessageChannel<>(

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

@@ -382,6 +382,12 @@ public void loadUrl(Long instanceId, String url, Map<String, String> headers) {
     webView.loadUrl(url, headers);
   }
 
+  @Override
+  public void postUrl(Long instanceId, String url, byte[] data) {
+    final WebView webView = (WebView) instanceManager.getInstance(instanceId);
+    webView.postUrl(url, data);
+  }
+
   @Override
   public String getUrl(Long instanceId) {
     final WebView webView = (WebView) instanceManager.getInstance(instanceId);

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

@@ -208,6 +208,12 @@ public void loadUrl() {
     verify(mockWebView).loadUrl("https://www.google.com", new HashMap<>());
   }
 
+  @Test
+  public void postUrl() {
+    testHostApiImpl.postUrl(0L, "https://www.google.com", new byte[] {0x01, 0x02});
+    verify(mockWebView).postUrl("https://www.google.com", new byte[] {0x01, 0x02});
+  }
+
   @Test
   public void getUrl() {
     when(mockWebView.getUrl()).thenReturn("https://www.google.com");

packages/webview_flutter/webview_flutter_android/example/lib/main.dart

@@ -7,6 +7,7 @@
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
+import 'dart:typed_data';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:path_provider/path_provider.dart';
@@ -158,6 +159,7 @@ enum _MenuOptions {
   navigationDelegate,
   loadLocalFile,
   loadHtmlString,
+  doPostRequest,
 }
 
 class _SampleMenu extends StatelessWidget {
@@ -201,6 +203,9 @@ class _SampleMenu extends StatelessWidget {
               case _MenuOptions.loadHtmlString:
                 _onLoadHtmlStringExample(controller.data!, context);
                 break;
+              case _MenuOptions.doPostRequest:
+                _onDoPostRequest(controller.data!, context);
+                break;
             }
           },
           itemBuilder: (BuildContext context) => <PopupMenuItem<_MenuOptions>>[
@@ -241,6 +246,10 @@ class _SampleMenu extends StatelessWidget {
               value: _MenuOptions.loadLocalFile,
               child: Text('Load local file'),
             ),
+            const PopupMenuItem<_MenuOptions>(
+              value: _MenuOptions.doPostRequest,
+              child: Text('Post Request'),
+            ),
           ],
         );
       },
@@ -330,6 +339,16 @@ class _SampleMenu extends StatelessWidget {
     await controller.loadHtmlString(kExamplePage);
   }
 
+  Future<void> _onDoPostRequest(
+      WebViewController controller, BuildContext context) async {
+    final WebViewRequest request = WebViewRequest(
+      uri: Uri.parse('https://httpbin.org/post'),
+      method: WebViewRequestMethod.post,
+      body: Uint8List.fromList('Test Body'.codeUnits),
+    );
+    await controller.loadRequest(request);
+  }
+
   Widget _getCookieList(String cookies) {
     if (cookies == null || cookies == '""') {
       return Container();

packages/webview_flutter/webview_flutter_android/example/lib/web_view.dart

@@ -402,6 +402,11 @@ class WebViewController {
     return _webViewPlatformController.loadUrl(url, headers);
   }
 
+  /// Loads a page by making the specified request.
+  Future<void> loadRequest(WebViewRequest request) async {
+    return _webViewPlatformController.loadRequest(request);
+  }
+
   /// Accessor to the current URL that the WebView is displaying.
   ///
   /// If [WebView.initialUrl] was never specified, returns `null`.