[webview_flutter_platform_interface] Adds platform interface for onHttpError callback (flutter#3645)

[webview_flutter_platform_interface] Adds platform interface for onHttpError callback

Author: HugoOlthof

packages/webview_flutter/webview_flutter_platform_interface/CHANGELOG.md

@@ -1,7 +1,9 @@
-## NEXT
+## 2.2.0
 
 * Updates minimum Flutter version to 3.3.
 * Fixes common typos in tests and documentation.
+* Adds support for listening to HTTP errors. See
+  `PlatformNavigationDelegate.setOnHttpError`.
 
 ## 2.1.0
 

packages/webview_flutter/webview_flutter_platform_interface/lib/src/platform_navigation_delegate.dart

@@ -19,6 +19,9 @@ typedef PageEventCallback = void Function(String url);
 /// Signature for callbacks that report loading progress of a page.
 typedef ProgressCallback = void Function(int progress);
 
+/// Signature for callbacks that report http errors during loading a page.
+typedef HttpResponseErrorCallback = void Function(HttpResponseError error);
+
 /// Signature for callbacks that report a resource loading error.
 typedef WebResourceErrorCallback = void Function(WebResourceError error);
 
@@ -90,6 +93,16 @@ abstract class PlatformNavigationDelegate extends PlatformInterface {
         'setOnPageFinished is not implemented on the current platform.');
   }
 
+  /// Invoked when an HTTP error has occurred during loading.
+  ///
+  /// See [PlatformWebViewController.setPlatformNavigationDelegate].
+  Future<void> setOnHttpError(
+    HttpResponseErrorCallback onHttpError,
+  ) {
+    throw UnimplementedError(
+        'setOnHttpError is not implemented on the current platform.');
+  }
+
   /// Invoked when a page is loading to report the progress.
   ///
   /// See [PlatformWebViewController.setPlatformNavigationDelegate].

packages/webview_flutter/webview_flutter_platform_interface/lib/src/types/http_response_error.dart

@@ -0,0 +1,45 @@
+// 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/foundation.dart';
+
+/// Error returned in `PlatformNavigationDelegate.setOnHttpError` when an HTTP
+/// response error has been received.
+///
+/// Platform specific implementations can add additional fields by extending
+/// this class.
+///
+/// This example demonstrates how to extend the [HttpResponseError] to
+/// provide additional platform specific parameters.
+///
+/// When extending [HttpResponseError] additional parameters should always
+/// accept `null` or have a default value to prevent breaking changes.
+///
+/// ```dart
+/// class IOSHttpResponseError extends HttpResponseError {
+///   IOSHttpResponseError._(HttpResponseError error, {required this.domain})
+///       : super(
+///           statusCode: error.statusCode,
+///         );
+///
+///   factory IOSHttpResponseError.fromHttpResponseError(
+///     HttpResponseError error, {
+///     required String? domain,
+///   }) {
+///     return IOSHttpResponseError._(error, domain: domain);
+///   }
+///
+///   final String? domain;
+/// }
+/// ```
+@immutable
+class HttpResponseError {
+  /// Used by the platform implementation to create a new [HttpResponseError].
+  const HttpResponseError({
+    required this.statusCode,
+  });
+
+  /// The HTTP status code.
+  final int statusCode;
+}

packages/webview_flutter/webview_flutter_platform_interface/lib/src/types/types.dart

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+export 'http_response_error.dart';
 export 'javascript_message.dart';
 export 'javascript_mode.dart';
 export 'load_request_params.dart';

packages/webview_flutter/webview_flutter_platform_interface/pubspec.yaml

@@ -4,7 +4,7 @@ repository: https://github.com/flutter/packages/tree/main/packages/webview_flutt
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+webview_flutter%22
 # NOTE: We strongly prefer non-breaking changes, even at the expense of a
 # less-clean API. See https://flutter.dev/go/platform-interface-breaking-changes
-version: 2.1.0
+version: 2.2.0
 
 environment:
   sdk: ">=2.18.0 <4.0.0"

packages/webview_flutter/webview_flutter_platform_interface/test/platform_navigation_delegate_test.dart

@@ -91,6 +91,20 @@ void main() {
   });
 
   test(
+      'Default implementation of setOnHttpError should throw unimplemented error',
+      () {
+    final PlatformNavigationDelegate callbackDelegate =
+        ExtendsPlatformNavigationDelegate(
+            const PlatformNavigationDelegateCreationParams());
+
+    expect(
+      () => callbackDelegate.setOnHttpError((HttpResponseError error) {}),
+      throwsUnimplementedError,
+    );
+  });
+
+  test(
+      // ignore: lines_longer_than_80_chars
       'Default implementation of setOnProgress should throw unimplemented error',
       () {
     final PlatformNavigationDelegate callbackDelegate =

packages/webview_flutter/webview_flutter_platform_interface/test/platform_webview_controller_test.mocks.dart

@@ -83,6 +83,16 @@ class MockPlatformNavigationDelegate extends _i1.Mock
         returnValueForMissingStub: _i4.Future<void>.value(),
       ) as _i4.Future<void>);
   @override
+  _i4.Future<void> setOnHttpError(_i3.HttpResponseErrorCallback? onHttpError) =>
+      (super.noSuchMethod(
+        Invocation.method(
+          #setOnHttpError,
+          [onHttpError],
+        ),
+        returnValue: _i4.Future<void>.value(),
+        returnValueForMissingStub: _i4.Future<void>.value(),
+      ) as _i4.Future<void>);
+  @override
   _i4.Future<void> setOnProgress(_i3.ProgressCallback? onProgress) =>
       (super.noSuchMethod(
         Invocation.method(