[webview_flutter] Support new onUrlChanged event on iOS.

packages/webview_flutter/webview_flutter_platform_interface/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 1.5.0
+
+* Added `onUrlChanged` callback to platform callback handler.
+
 ## 1.4.0
 
 * Added `loadFile` and `loadHtml` interface methods.

packages/webview_flutter/webview_flutter_platform_interface/lib/src/method_channel/webview_method_channel.dart

@@ -53,6 +53,9 @@ class MethodChannelWebViewPlatform implements WebViewPlatformController {
       case 'onPageStarted':
         _platformCallbacksHandler.onPageStarted(call.arguments['url']!);
         return null;
+      case 'onUrlChanged':
+        _platformCallbacksHandler.onUrlChanged(call.arguments['url']!);
+        return null;
       case 'onWebResourceError':
         _platformCallbacksHandler.onWebResourceError(
           WebResourceError(

packages/webview_flutter/webview_flutter_platform_interface/lib/src/platform_interface/webview_platform_callbacks_handler.dart

@@ -24,9 +24,16 @@ abstract class WebViewPlatformCallbacksHandler {
   void onPageFinished(String url);
 
   /// Invoked by [WebViewPlatformController] when a page is loading.
-  /// /// Only works when [WebSettings.hasProgressTracking] is set to `true`.
+  /// Only works when [WebSettings.hasProgressTracking] is set to `true`.
   void onProgress(int progress);
 
+  /// Invoked by [WebViewPlatformController] when the webview's URL has changed.
+  ///
+  /// Unlike [onPageStarted], [onProgress], and [onPageFinished],
+  /// [onUrlChanged] also fires when navigating without a full page load
+  /// e.g. when using a single page application.
+  void onUrlChanged(String url);
+
   /// Report web resource loading error to the host application.
   void onWebResourceError(WebResourceError error);
 }

packages/webview_flutter/webview_flutter_platform_interface/pubspec.yaml

@@ -4,7 +4,7 @@ repository: https://github.com/flutter/plugins/tree/master/packages/webview_flut
 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: 1.4.0
+version: 1.5.0
 
 environment:
   sdk: ">=2.12.0 <3.0.0"

packages/webview_flutter/webview_flutter_platform_interface/test/src/method_channel/webview_method_channel_test.dart

@@ -13,7 +13,9 @@ import 'package:webview_flutter_platform_interface/webview_flutter_platform_inte
 void main() {
   TestWidgetsFlutterBinding.ensureInitialized();
 
-  group('Tests on `plugin.flutter.io/webview_<channel_id>` channel', () {
+  group(
+      'Tests on `plugin.flutter.io/webview_<channel_id>` channel dart->native',
+      () {
     const int channelId = 1;
     const MethodChannel channel =
         MethodChannel('plugins.flutter.io/webview_$channelId');
@@ -554,6 +556,40 @@ void main() {
     });
   });
 
+  group(
+      'Tests on `plugin.flutter.io/webview_<channel_id>` channel native->dart',
+      () {
+    const int channelId = 1;
+    final WebViewPlatformCallbacksHandler callbacksHandler =
+        MockWebViewPlatformCallbacksHandler();
+    final JavascriptChannelRegistry javascriptChannelRegistry =
+        MockJavascriptChannelRegistry();
+
+    MethodChannelWebViewPlatform(
+      channelId,
+      callbacksHandler,
+      javascriptChannelRegistry,
+    );
+
+    tearDown(() {
+      reset(callbacksHandler);
+    });
+
+    test('onUrlChanged', () async {
+      // Run
+      await ServicesBinding.instance!.defaultBinaryMessenger
+          .handlePlatformMessage(
+        'plugins.flutter.io/webview_$channelId',
+        StandardMethodCodec()
+            .encodeMethodCall(MethodCall('onUrlChanged', {'url': 'Test Url'})),
+        null,
+      );
+
+      // Verify
+      verify(callbacksHandler.onUrlChanged('Test Url'));
+    });
+  });
+
   group('Tests on `plugins.flutter.io/cookie_manager` channel', () {
     const MethodChannel cookieChannel =
         MethodChannel('plugins.flutter.io/cookie_manager');

packages/webview_flutter/webview_flutter_wkwebview/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 2.5.0
+
+* Support new `onUrlChanged` event in platform interface.
+
 ## 2.4.0
 
 * Implemented new `loadFile` and `loadHtmlString` methods from the platform interface.

packages/webview_flutter/webview_flutter_wkwebview/example/ios/RunnerTests/FLTWKNavigationDelegateTests.m

@@ -69,4 +69,38 @@ - (void)testWebViewWebEvaluateJavaScriptShouldNotBeCalledWhenShouldEnableZoomIsT
   [self.navigationDelegate webView:webview didFinishNavigation:navigation];
 }
 
+- (void)testWebViewObserveValueForKeyPathCallsMethodChannelOnURLChange {
+  [self.navigationDelegate
+      observeValueForKeyPath:@"URL"
+                    ofObject:nil
+                      change:@{
+                        NSKeyValueChangeNewKey : [NSURL URLWithString:@"https://flutter.dev/"]
+                      }
+                     context:nil];
+  OCMVerify([self.mockMethodChannel
+      invokeMethod:@"onUrlChanged"
+         arguments:[OCMArg isEqual:@{@"url" : @"https://flutter.dev/"}]]);
+}
+
+- (void)testWebViewObserveValueForKeyPathReturnsForNonURLChanges {
+  [self.navigationDelegate
+      observeValueForKeyPath:@"IRRELEVANT_PATH"
+                    ofObject:nil
+                      change:@{
+                        NSKeyValueChangeNewKey : [NSURL URLWithString:@"https://flutter.dev/"]
+                      }
+                     context:nil];
+
+  OCMReject([self.mockMethodChannel invokeMethod:[OCMArg any] arguments:[OCMArg any]]);
+}
+
+- (void)testWebViewObserveValueForKeyPathReturnsForNSNullURLChanges {
+  [self.navigationDelegate observeValueForKeyPath:@"URL"
+                                         ofObject:nil
+                                           change:@{NSKeyValueChangeNewKey : [NSNull null]}
+                                          context:nil];
+
+  OCMReject([self.mockMethodChannel invokeMethod:[OCMArg any] arguments:[OCMArg any]]);
+}
+
 @end

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

@@ -35,6 +35,9 @@ typedef void PageFinishedCallback(String url);
 /// Signature for when a [WebView] is loading a page.
 typedef void PageLoadingCallback(int progress);
 
+/// Signature for when a [WebView] changed its current URL.
+typedef void UrlChangedCallback(String url);
+
 /// Signature for when a [WebView] has failed to load a resource.
 typedef void WebResourceErrorCallback(WebResourceError error);
 
@@ -61,6 +64,7 @@ class WebView extends StatefulWidget {
     this.onPageStarted,
     this.onPageFinished,
     this.onProgress,
+    this.onUrlChanged,
     this.onWebResourceError,
     this.debuggingEnabled = false,
     this.gestureNavigationEnabled = false,
@@ -175,6 +179,9 @@ class WebView extends StatefulWidget {
   /// Invoked when a page is loading.
   final PageLoadingCallback? onProgress;
 
+  /// Invoked when a webview's URL has changed.
+  final UrlChangedCallback? onUrlChanged;
+
   /// Invoked when a web resource has failed to load.
   ///
   /// This callback is only called for the main page.
@@ -645,6 +652,13 @@ class _PlatformCallbacksHandler implements WebViewPlatformCallbacksHandler {
     }
   }
 
+  @override
+  void onUrlChanged(String url) {
+    if (_webView.onUrlChanged != null) {
+      _webView.onUrlChanged!(url);
+    }
+  }
+
   void onWebResourceError(WebResourceError error) {
     if (_webView.onWebResourceError != null) {
       _webView.onWebResourceError!(error);

packages/webview_flutter/webview_flutter_wkwebview/ios/Classes/FLTWKNavigationDelegate.m

@@ -16,6 +16,19 @@ - (instancetype)initWithChannel:(FlutterMethodChannel *)channel {
   return self;
 }
 
+- (void)observeValueForKeyPath:(NSString *)keyPath
+                      ofObject:(id)object
+                        change:(NSDictionary<NSKeyValueChangeKey, id> *)change
+                       context:(void *)context {
+  if (![keyPath isEqualToString:@"URL"]) {
+    return;
+  }
+  NSURL *newURL = [change objectForKey:NSKeyValueChangeNewKey];
+  if (![newURL isEqual:[NSNull null]]) {
+    [_methodChannel invokeMethod:@"onUrlChanged" arguments:@{@"url" : newURL.absoluteString}];
+  }
+}
+
 #pragma mark - WKNavigationDelegate conformance
 
 - (void)webView:(WKWebView *)webView didStartProvisionalNavigation:(WKNavigation *)navigation {

packages/webview_flutter/webview_flutter_wkwebview/ios/Classes/FlutterWebView.m

@@ -110,6 +110,10 @@ - (instancetype)initWithFrame:(CGRect)frame
         _webView.scrollView.automaticallyAdjustsScrollIndicatorInsets = NO;
       }
     }
+    [_webView addObserver:_navigationDelegate
+               forKeyPath:@"URL"
+                  options:NSKeyValueObservingOptionNew
+                  context:NULL];
 
     [self applySettings:settings];
     // TODO(amirh): return an error if apply settings failed once it's possible to do so.

packages/webview_flutter/webview_flutter_wkwebview/pubspec.yaml

@@ -2,7 +2,7 @@ name: webview_flutter_wkwebview
 description: A Flutter plugin that provides a WebView widget based on Apple's WKWebView control.
 repository: https://github.com/flutter/plugins/tree/master/packages/webview_flutter/webview_flutter_wkwebview
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+webview%22
-version: 2.4.0
+version: 2.5.0
 
 environment:
   sdk: ">=2.14.0 <3.0.0"
@@ -18,7 +18,9 @@ flutter:
 dependencies:
   flutter:
     sdk: flutter
-  webview_flutter_platform_interface: ^1.3.0
+  #TODO (BeMacized): CHANGE TO VERSION DEPENDENCY ONCE UPDATED PLATFORM INTERFACE HAS BEEN PUBLISHED.
+  webview_flutter_platform_interface:
+    path: ../webview_flutter_platform_interface
 
 dev_dependencies:
   flutter_driver: