WebView for Flutter
A Flutter plugin that provides a WebView widget.
On iOS the WebView widget is backed by a WKWebView. On Android the WebView widget is backed by a WebView.
Android | iOS | |
---|---|---|
Support | SDK 19+ or 20+ | 11.0+ |
Usage
Add webview_flutter
as a dependency in your pubspec.yaml file.
You can now display a WebView by:
- Instantiating a WebViewController.
controller = WebViewController()
..setJavaScriptMode(JavaScriptMode.unrestricted)
..setBackgroundColor(const Color(0x00000000))
..setNavigationDelegate(
NavigationDelegate(
onProgress: (int progress) {
// Update loading bar.
},
onPageStarted: (String url) {},
onPageFinished: (String url) {},
onWebResourceError: (WebResourceError error) {},
onNavigationRequest: (NavigationRequest request) {
if (request.url.startsWith('https://www.youtube.com/')) {
return NavigationDecision.prevent;
}
return NavigationDecision.navigate;
},
),
)
..loadRequest(Uri.parse('https://flutter.dev'));
- Passing the controller to a WebViewWidget.
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: const Text('Flutter Simple Example')),
body: WebViewWidget(controller: controller),
);
}
See the Dartdocs for WebViewController and WebViewWidget for more details.
Android Platform Views
This plugin uses Platform Views to embed the Android’s WebView within the Flutter app.
You should however make sure to set the correct minSdkVersion
in android/app/build.gradle
if it was previously lower than 19:
android {
defaultConfig {
minSdkVersion 19
}
}
Platform-Specific Features
Many classes have a subclass or an underlying implementation that provides access to platform-specific features.
To access platform-specific features, start by adding the platform implementation packages to your app or package:
- Android: webview_flutter_android
- iOS: webview_flutter_wkwebview
Next, add the imports of the implementation packages to your app or package:
// Import for Android features.
import 'package:webview_flutter_android/webview_flutter_android.dart';
// Import for iOS features.
import 'package:webview_flutter_wkwebview/webview_flutter_wkwebview.dart';
Now, additional features can be accessed through the platform implementations. Classes WebViewController, WebViewWidget, NavigationDelegate, and WebViewCookieManager pass their functionality to a class provided by the current platform. Below are a couple of ways to access additional functionality provided by the platform and is followed by an example.
- Pass a creation params class provided by a platform implementation to a
fromPlatformCreationParams
constructor (e.g.WebViewController.fromPlatformCreationParams
,WebViewWidget.fromPlatformCreationParams
, etc.). - Call methods on a platform implementation of a class by using the
platform
field (e.g.WebViewController.platform
,WebViewWidget.platform
, etc.).
Below is an example of setting additional iOS and Android parameters on the WebViewController
.
late final PlatformWebViewControllerCreationParams params;
if (WebViewPlatform.instance is WebKitWebViewPlatform) {
params = WebKitWebViewControllerCreationParams(
allowsInlineMediaPlayback: true,
mediaTypesRequiringUserAction: const <PlaybackMediaTypes>{},
);
} else {
params = const PlatformWebViewControllerCreationParams();
}
final WebViewController controller =
WebViewController.fromPlatformCreationParams(params);
// ···
if (controller.platform is AndroidWebViewController) {
AndroidWebViewController.enableDebugging(true);
(controller.platform as AndroidWebViewController)
.setMediaPlaybackRequiresUserGesture(false);
}
See https://pub.dev/documentation/webview_flutter_android/latest/webview_flutter_android/webview_flutter_android-library.html for more details on Android features.
See https://pub.dev/documentation/webview_flutter_wkwebview/latest/webview_flutter_wkwebview/webview_flutter_wkwebview-library.html for more details on iOS features.
Enable Material Components for 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.
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.
Migrating from 3.0 to 4.0
Instantiating WebViewController
In version 3.0 and below, WebViewController
could only be retrieved in a callback after the
WebView
was added to the widget tree. Now, WebViewController
must be instantiated and can be
used before it is added to the widget tree. See Usage
section above for an example.
Replacing WebView Functionality
The WebView
class has been removed and its functionality has been split into WebViewController
and WebViewWidget
.
WebViewController
handles all functionality that is associated with the underlying web view
provided by each platform. (e.g., loading a url, setting the background color of the underlying
platform view, or clearing the cache).
WebViewWidget
takes a WebViewController
and handles all Flutter widget related functionality
(e.g., layout direction, gesture recognizers).
See the Dartdocs for WebViewController and WebViewWidget for more details.
PlatformView Implementation on Android
The PlatformView implementation for Android uses Texture Layer Hybrid Composition on versions 23+
and automatically fallbacks to Hybrid Composition for version 19-23. See section
Platform-Specific Features
and AndroidWebViewWidgetCreationParams.displayWithHybridComposition
to manually switch to Hybrid Composition on versions 23+.
API Changes
Below is a non-exhaustive list of changes to the API:
WebViewController.clearCache
no longer clears local storage. Please useWebViewController.clearLocalStorage
.WebViewController.clearCache
no longer reloads the page.WebViewController.loadUrl
has been removed. Please useWebViewController.loadRequest
.WebViewController.evaluateJavascript
has been removed. Please useWebViewController.runJavaScript
orWebViewController.runJavaScriptReturningResult
.WebViewController.getScrollX
andWebViewController.getScrollY
have been removed and have been replaced byWebViewController.getScrollPosition
.WebViewController.runJavaScriptReturningResult
now returns anObject
and not aString
. This will attempt to return abool
ornum
if the return value can be parsed.WebView.initialCookies
has been removed. UseWebViewCookieManager.setCookie
before callingWebViewController.loadRequest
.CookieManager
is replaced byWebViewCookieManager
.NavigationDelegate.onWebResourceError
callback includes errors that are not from the main frame. Use theWebResourceError.isForMainFrame
field to filter errors.- The following fields from
WebView
have been moved toNavigationDelegate
. They can be added to a WebView withWebViewController.setNavigationDelegate
.WebView.navigationDelegate
->NavigationDelegate.onNavigationRequest
WebView.onPageStarted
->NavigationDelegate.onPageStarted
WebView.onPageFinished
->NavigationDelegate.onPageFinished
WebView.onProgress
->NavigationDelegate.onProgress
WebView.onWebResourceError
->NavigationDelegate.onWebResourceError
- The following fields from
WebView
have been moved toWebViewController
:WebView.javascriptMode
->WebViewController.setJavaScriptMode
WebView.javascriptChannels
->WebViewController.addJavaScriptChannel
/WebViewController.removeJavaScriptChannel
WebView.zoomEnabled
->WebViewController.enableZoom
WebView.userAgent
->WebViewController.setUserAgent
WebView.backgroundColor
->WebViewController.setBackgroundColor
- The following features have been moved to an Android implementation class. See section
Platform-Specific Features
for details on accessing Android platform-specific features.WebView.debuggingEnabled
->static AndroidWebViewController.enableDebugging
WebView.initialMediaPlaybackPolicy
->AndroidWebViewController.setMediaPlaybackRequiresUserGesture
- The following features have been moved to an iOS implementation class. See section
Platform-Specific Features
for details on accessing iOS platform-specific features.WebView.gestureNavigationEnabled
->WebKitWebViewController.setAllowsBackForwardNavigationGestures
WebView.initialMediaPlaybackPolicy
->WebKitWebViewControllerCreationParams.mediaTypesRequiringUserAction
WebView.allowsInlineMediaPlayback
->WebKitWebViewControllerCreationParams.allowsInlineMediaPlayback