[webview_flutter] Send history events

wwwdata · wwwdata · commit 02a610eef477 · 2019-12-10T13:31:27.000+01:00
Send URL change events when the user navigates in the Browser. This also
works for JavaScript Navigation that does not actually make any request.
diff --git a/packages/webview_flutter/CHANGELOG.md b/packages/webview_flutter/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.3.19
+
+* Add support for Navigation History observation.
+
 ## 0.3.18
 
 * Add support for onPageStarted event.
diff --git a/packages/webview_flutter/android/src/main/java/io/flutter/plugins/webviewflutter/FlutterWebViewClient.java b/packages/webview_flutter/android/src/main/java/io/flutter/plugins/webviewflutter/FlutterWebViewClient.java
@@ -92,6 +92,12 @@ private void notifyOnNavigationRequest(
     }
   }
 
+  private void onUpdateVisitedHistory(String url) {
+    HashMap<String, Object> args = new HashMap<>();
+    args.put("url", url);
+    methodChannel.invokeMethod("onUpdateVisitedHistory", args);
+  }
+
   // This method attempts to avoid using WebViewClientCompat due to bug
   // https://bugs.chromium.org/p/chromium/issues/detail?id=925887. Also, see
   // https://github.com/flutter/flutter/issues/29446.
@@ -107,6 +113,12 @@ WebViewClient createWebViewClient(boolean hasNavigationDelegate) {
 
   private WebViewClient internalCreateWebViewClient() {
     return new WebViewClient() {
+      @Override
+      public void doUpdateVisitedHistory(WebView view, String url, boolean isReload) {
+        FlutterWebViewClient.this.onUpdateVisitedHistory(url);
+        super.doUpdateVisitedHistory(view, url, isReload);
+      }
+
       @TargetApi(Build.VERSION_CODES.N)
       @Override
       public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) {
@@ -134,6 +146,12 @@ public void onUnhandledKeyEvent(WebView view, KeyEvent event) {
 
   private WebViewClientCompat internalCreateWebViewClientCompat() {
     return new WebViewClientCompat() {
+      @Override
+      public void doUpdateVisitedHistory(WebView view, String url, boolean isReload) {
+        FlutterWebViewClient.this.onUpdateVisitedHistory(url);
+        super.doUpdateVisitedHistory(view, url, isReload);
+      }
+
       @Override
       public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) {
         return FlutterWebViewClient.this.shouldOverrideUrlLoading(view, request);
diff --git a/packages/webview_flutter/example/lib/main.dart b/packages/webview_flutter/example/lib/main.dart
@@ -74,6 +74,9 @@ class _WebViewExampleState extends State<WebViewExample> {
           onPageFinished: (String url) {
             print('Page finished loading: $url');
           },
+          onUpdateVisitedHistory: (String url) {
+            print('Update visited history: $url');
+          },
         );
       }),
       floatingActionButton: favoriteButton(),
diff --git a/packages/webview_flutter/example/test_driver/webview_flutter_e2e.dart b/packages/webview_flutter/example/test_driver/webview_flutter_e2e.dart
@@ -652,6 +652,60 @@ void main() {
       expect(currentUrl, 'https://www.google.com/');
     });
   });
+
+  testWidgets('onUpdateVisitedHistory triggers when the URL changes',
+      (WidgetTester tester) async {
+    final String onUpdateVisitedHistoryTest = '''
+        <!DOCTYPE html><html>
+        <head><title>onUpdateVisitedHistory test</title>
+          <script type="text/javascript">
+            function changeHash() {
+              window.location.href = 'https://www.google.com/';
+            }
+          </script>
+        </head>
+        <body onload="changeHash();" bgColor="blue">
+        </body>
+        </html>
+      ''';
+    final String onUpdateVisitedHistoryTestBase64 =
+        base64Encode(const Utf8Encoder().convert(onUpdateVisitedHistoryTest));
+    final Completer<String> onUpdateVisitedHistoryCompleter =
+        Completer<String>();
+    final GlobalKey key = GlobalKey();
+
+    final String initialUrl =
+        'data:text/html;charset=utf-8;base64,$onUpdateVisitedHistoryTestBase64';
+
+    final WebView webView = WebView(
+        key: key,
+        initialUrl: initialUrl,
+        javascriptMode: JavascriptMode.unrestricted,
+        onUpdateVisitedHistory: (String newUrl) {
+          if (newUrl == initialUrl) {
+            return;
+          }
+          onUpdateVisitedHistoryCompleter.complete(newUrl);
+        });
+
+    await tester.pumpWidget(
+      Directionality(
+        textDirection: TextDirection.ltr,
+        child: Column(
+          children: <Widget>[
+            SizedBox(
+              width: 200,
+              height: 200,
+              child: webView,
+            ),
+          ],
+        ),
+      ),
+    );
+
+    final String nextUrl = await onUpdateVisitedHistoryCompleter.future;
+    expect(nextUrl, 'https://www.google.com/');
+  });
 }
 
 // JavaScript booleans evaluate to different string values on Android and iOS.
diff --git a/packages/webview_flutter/ios/Classes/FLTWKHistoryDelegate.h b/packages/webview_flutter/ios/Classes/FLTWKHistoryDelegate.h
@@ -0,0 +1,16 @@
+// Copyright 2019 The Chromium 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 <Flutter/Flutter.h>
+#import <Foundation/Foundation.h>
+#import <WebKit/WebKit.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface FLTWKHistoryDelegate : NSObject
+- (instancetype)initWithWebView:(WKWebView *)webView channel:(FlutterMethodChannel *)channel;
+- (void)stopObserving:(WKWebView *)webView;
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/packages/webview_flutter/ios/Classes/FLTWKHistoryDelegate.m b/packages/webview_flutter/ios/Classes/FLTWKHistoryDelegate.m
@@ -0,0 +1,42 @@
+// Copyright 2019 The Chromium 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 "FLTWKHistoryDelegate.h"
+
+NSString *const keyPath = @"URL";
+
+@implementation FLTWKHistoryDelegate {
+  FlutterMethodChannel *_methodChannel;
+}
+
+- (instancetype)initWithWebView:(id)webView channel:(FlutterMethodChannel *)channel {
+  self = [super init];
+  if (self) {
+    _methodChannel = channel;
+    [webView addObserver:self
+              forKeyPath:keyPath
+                 options:NSKeyValueObservingOptionNew | NSKeyValueObservingOptionOld
+                 context:nil];
+  }
+
+  return self;
+}
+
+- (void)stopObserving:(WKWebView *)webView {
+  [webView removeObserver:self forKeyPath:keyPath];
+}
+
+- (void)observeValueForKeyPath:(NSString *)keyPath
+                      ofObject:(id)object
+                        change:(NSDictionary *)change
+                       context:(void *)context {
+  if ([keyPath isEqualToString:keyPath] &&
+      [change[NSKeyValueChangeNewKey] isKindOfClass:[NSURL class]]) {
+    NSURL *newUrl = change[NSKeyValueChangeNewKey];
+    [_methodChannel invokeMethod:@"onUpdateVisitedHistory"
+                       arguments:@{@"url" : [newUrl absoluteString]}];
+  }
+}
+
+@end
diff --git a/packages/webview_flutter/ios/Classes/FlutterWebView.m b/packages/webview_flutter/ios/Classes/FlutterWebView.m
@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 #import "FlutterWebView.h"
+#import "FLTWKHistoryDelegate.h"
 #import "FLTWKNavigationDelegate.h"
 #import "JavaScriptChannelHandler.h"
 
@@ -42,6 +43,7 @@ @implementation FLTWebViewController {
   // The set of registered JavaScript channel names.
   NSMutableSet* _javaScriptChannelNames;
   FLTWKNavigationDelegate* _navigationDelegate;
+  FLTWKHistoryDelegate* _historyDelegate;
 }
 
 - (instancetype)initWithFrame:(CGRect)frame
@@ -72,6 +74,7 @@ - (instancetype)initWithFrame:(CGRect)frame
     _webView = [[WKWebView alloc] initWithFrame:frame configuration:configuration];
     _navigationDelegate = [[FLTWKNavigationDelegate alloc] initWithChannel:_channel];
     _webView.navigationDelegate = _navigationDelegate;
+    _historyDelegate = [[FLTWKHistoryDelegate alloc] initWithWebView:_webView channel:_channel];
     __weak __typeof__(self) weakSelf = self;
     [_channel setMethodCallHandler:^(FlutterMethodCall* call, FlutterResult result) {
       [weakSelf onMethodCall:call result:result];
@@ -89,6 +92,12 @@ - (instancetype)initWithFrame:(CGRect)frame
   return self;
 }
 
+- (void)dealloc {
+  if (_historyDelegate != nil) {
+    [_historyDelegate stopObserving:_webView];
+  }
+}
+
 - (UIView*)view {
   return _webView;
 }
diff --git a/packages/webview_flutter/lib/platform_interface.dart b/packages/webview_flutter/lib/platform_interface.dart
@@ -28,6 +28,9 @@ abstract class WebViewPlatformCallbacksHandler {
 
   /// Invoked by [WebViewPlatformController] when a page has finished loading.
   void onPageFinished(String url);
+
+  /// Invoked by [WebViewPlatformController] when the url has changed.
+  void onUpdateVisitedHistory(String url);
 }
 
 /// Interface for talking to the webview's platform implementation.
diff --git a/packages/webview_flutter/lib/src/webview_method_channel.dart b/packages/webview_flutter/lib/src/webview_method_channel.dart
@@ -43,6 +43,9 @@ class MethodChannelWebViewPlatform implements WebViewPlatformController {
       case 'onPageStarted':
         _platformCallbacksHandler.onPageStarted(call.arguments['url']);
         return null;
+      case 'onUpdateVisitedHistory':
+        _platformCallbacksHandler.onUpdateVisitedHistory(call.arguments['url']);
+        return null;
     }
     throw MissingPluginException(
         '${call.method} was invoked but has no handler');
diff --git a/packages/webview_flutter/lib/webview_flutter.dart b/packages/webview_flutter/lib/webview_flutter.dart
@@ -79,6 +79,9 @@ typedef void PageStartedCallback(String url);
 /// Signature for when a [WebView] has finished loading a page.
 typedef void PageFinishedCallback(String url);
 
+/// Signature for when an Android [WebView] had a history update.
+typedef void PageUpdateVisitedHistoryCallback(String url);
+
 /// Specifies possible restrictions on automatic media playback.
 ///
 /// This is typically used in [WebView.initialMediaPlaybackPolicy].
@@ -147,6 +150,7 @@ class WebView extends StatefulWidget {
     this.gestureRecognizers,
     this.onPageStarted,
     this.onPageFinished,
+    this.onUpdateVisitedHistory,
     this.debuggingEnabled = false,
     this.userAgent,
     this.initialMediaPlaybackPolicy =
@@ -276,6 +280,14 @@ class WebView extends StatefulWidget {
   /// [WebViewController.evaluateJavascript] can assume this.
   final PageFinishedCallback onPageFinished;
 
+  /// Invoked when the URL in the browser changed.
+  ///
+  /// While it is possible to see all URL changes in the [navigationDelegate]
+  /// in iOS. This is not the case for Android when JavaScript updates the URL.
+  /// So when you need an update as soon as the browser is on a different URL,
+  /// use this callback.
+  final PageUpdateVisitedHistoryCallback onUpdateVisitedHistory;
+
   /// Controls whether WebView debugging is enabled.
   ///
   /// Setting this to true enables [WebView debugging on Android](https://developers.google.com/web/tools/chrome-devtools/remote-debugging/).
@@ -473,6 +485,13 @@ class _PlatformCallbacksHandler implements WebViewPlatformCallbacksHandler {
     }
   }
 
+  @override
+  void onUpdateVisitedHistory(String url) {
+    if (_widget.onUpdateVisitedHistory != null) {
+      _widget.onUpdateVisitedHistory(url);
+    }
+  }
+
   void _updateJavascriptChannelsFromSet(Set<JavascriptChannel> channels) {
     _javascriptChannels.clear();
     if (channels == null) {
diff --git a/packages/webview_flutter/pubspec.yaml b/packages/webview_flutter/pubspec.yaml
@@ -1,6 +1,6 @@
 name: webview_flutter
 description: A Flutter plugin that provides a WebView widget on Android and iOS.
-version: 0.3.18
+version: 0.3.19
 homepage: https://github.com/flutter/plugins/tree/master/packages/webview_flutter
 
 environment:
diff --git a/packages/webview_flutter/test/webview_flutter_test.dart b/packages/webview_flutter/test/webview_flutter_test.dart
@@ -887,6 +887,22 @@ void main() {
 
     expect(platformWebView.userAgent, 'UA');
   });
+  testWidgets('onUpdateVisitedHistory', (WidgetTester tester) async {
+    String visitedUrl;
+
+    await tester.pumpWidget(WebView(
+        initialUrl: 'https://youtube.com',
+        onUpdateVisitedHistory: (String url) {
+          visitedUrl = url;
+        }));
+
+    final FakePlatformWebView platformWebView =
+        fakePlatformViewsController.lastCreatedView;
+
+    platformWebView.fakeOnUpdateVisitedHistoryCallback('https://google.com');
+
+    expect(visitedUrl, 'https://google.com');
+  });
 }
 
 class FakePlatformWebView {
@@ -1061,6 +1077,24 @@ class FakePlatformWebView {
     );
   }
 
+  void fakeOnUpdateVisitedHistoryCallback(String nextUrl) {
+    final StandardMethodCodec codec = const StandardMethodCodec();
+
+    final ByteData data = codec.encodeMethodCall(MethodCall(
+      'onUpdateVisitedHistory',
+      <dynamic, dynamic>{'url': nextUrl},
+    ));
+
+    // TODO(hterkelsen): Remove this when defaultBinaryMessages is in stable.
+    // https://github.com/flutter/flutter/issues/33446
+    // ignore: deprecated_member_use
+    BinaryMessages.handlePlatformMessage(
+      channel.name,
+      data,
+      (ByteData data) {},
+    );
+  }
+
   void _loadUrl(String url) {
     history = history.sublist(0, currentPosition + 1);
     history.add(url);

Original file line number	Diff line number	Diff line change
`@@ -28,6 +28,9 @@ abstract class WebViewPlatformCallbacksHandler {`
`28`	`28`
`29`	`29`	`/// Invoked by [WebViewPlatformController] when a page has finished loading.`
`30`	`30`	`void onPageFinished(String url);`
	`31`	`+`
	`32`	`+ /// Invoked by [WebViewPlatformController] when the url has changed.`
	`33`	`+ void onUpdateVisitedHistory(String url);`
`31`	`34`	`}`
`32`	`35`
`33`	`36`	`/// Interface for talking to the webview's platform implementation.`