A feature-rich cross-platform webview using webview_flutter for mobile and iframe for web. JS interop-ready.
late WebViewXController webviewController;
2. Add the WebViewX widget inside the build method, and set the onWebViewCreated
callback in order to retrieve the controller when the webview is initialized
WebViewX(
initialContent: '<h2> Hello, world! </h2>',
initialSourceType: SourceType.HTML,
onWebViewCreated: (controller) => webviewController = controller,
...
... other options
);
If you need to add other widgets on top of the webview (e.g. inside a Stack widget), you MUST wrap those widgets with a WebViewAware widget. This does nothing on mobile, but on web it allows widgets on top to intercept gestures. Otherwise, those widgets may not be clickable and/or the iframe will behave weird (unexpected refresh/reload - this is a well known issue).
Also, if you add widgets on top of the webview, wrap them and then you notice that the iframe still reloads unexpectedly, you should check if there are other widgets that sit on top without being noticed, or try to wrap InkWell, GestureRecognizer or Button widgets to see which one causes the problem.
3. Interact with the controller (run the example app to check out some use cases)
webviewController.loadContent(
'https://flutter.dev',
SourceType.url,
);
webviewController.goBack();
webviewController.goForward();
...
...
Note: For more detailed information about things such as EmbeddedJsContent
, please visit each own's .dart
file from the utils
folder.
Feature | Details |
---|---|
String initialContent |
Initial webview content |
SourceType initialSourceType |
Initial webview content type (url, urlBypass or html ) |
String? userAgent |
User agent |
double? width |
Widget's width (if null, it takes all available space) |
double? height |
Widget's height (if null, it takes all available space) |
Function(WebViewXController controller)? onWebViewCreated |
Callback that gets executed when the webview has initialized |
Set<EmbeddedJsContent> jsContent |
A set of EmbeddedJsContent, which is an object that defines some javascript which will be embedded in the page, once loaded (check the example app) |
Set<DartCallback> dartCallBacks |
A set of DartCallback, which is an object that defines a dart callback function, which will be called from javascript (check the example app) |
bool ignoreAllGestures |
Boolean value that specifies if the widget should ignore all gestures right after it is initialized |
JavascriptMode javascriptMode |
This specifies if Javascript should be allowed to execute, or not (allowed by default, you must allow it in order to use above features) |
AutoMediaPlaybackPolicy initialMediaPlaybackPolicy |
This specifies if media content should be allowed to autoplay when initialized (i.e when the page is loaded) |
void Function(String src)? onPageStarted |
Callback that gets executed when a page starts loading (e.g. after you change the content) |
void Function(String src)? onPageFinished |
Callback that gets executed when a page finishes loading |
NavigationDelegate? navigationDelegate |
Callback that, if not null, gets executed when the user clicks something in the webview (on Web it only works for SourceType.urlBypass , for now) |
void Function(WebResourceError error)? onWebResourceError |
Callback that gets executed when there is an error when loading resources ( issues on web ) |
WebSpecificParams webSpecificParams |
This is an object that contains web-specific options. Theese are not available on mobile (yet) |
MobileSpecificParams mobileSpecificParams |
This is an object that contains mobile-specific options. Theese are not available on web (yet) |
Feature | Usage |
---|---|
Load URL that allows iframe embedding | webviewController.loadContent(URL, SourceType.URL) |
Load URL that doesnt allow iframe embedding | webviewController.loadContent(URL, SourceType.URL_BYPASS) |
Load URL that doesnt allow iframe embedding, with headers | webviewController.loadContent(URL, SourceType.URL_BYPASS, headers: {'x-something': 'value'}) |
Load HTML from string | webviewController.loadContent(HTML, SourceType.HTML) |
Load HTML from assets | webviewController.loadContent(HTML, SourceType.HTML, fromAssets: true) |
Check if you can go back in history | webviewController.canGoBack() |
Go back in history | webviewController.goBack() |
Check if you can go forward in history | webviewController.canGoForward() |
Go forward in history | webviewController.goForward() |
Reload current content | webviewController.reload() |
Check if all gestures are ignored | webviewController.ignoringAllGestures |
Set ignore all gestures | webviewController.setIgnoreAllGestures(value) |
Evaluate "raw" javascript code | webviewController.evalRawJavascript(JS) |
Evaluate "raw" javascript code in global context ("page") | webviewController.evalRawJavascript(JS, inGlobalContext: true) |
Call a JS method | webviewController.callJsMethod(METHOD_NAME, PARAMS_LIST) |
Retrieve webview's content | webviewController.getContent() |
Get scroll position on X axis | webviewController.getScrollX() |
Get scroll position on Y axis | webviewController.getScrollY() |
Scrolls by x on X axis and by y on Y axis |
webviewController.scrollBy(int x, int y) |
Scrolls exactly to the position (x, y) |
webviewController.scrollTo(int x, int y) |
Retrieves the inner page title | webviewController.getTitle() |
Clears cache | webviewController.clearCache() |
While this package aims to put together the best of both worlds, there are differences between web and mobile.
-
Running and building
First, this package was being developed while the default
web renderer
washtml
. Now(Flutter 2, Dart 2.12), the default renderer iscanvaskit
.From my experience, this package does behave a little bit weird on canvaskit, so you should use the
html
renderer.To do this, you have to run your ordinary
flutter run -d chrome
command with the--web-renderer html
extra argument, like this:flutter run -d chrome --web-renderer html
for running and
flutter build web --web-renderer html
for building.
-
Diferences between Web and Mobile behaviour:
See issues/#27
-
About content loading on Web
To make the web version (iframe) work as it is, I had to use some of the code from x-frame bypass in order to make a request to a CORS proxy, which removes the headers that block iframe embeddings.
This might seem like a hack, and it really is, but I couldn't find any other way to make the iframe behave similar to the mobile webview (which is some kind of an actual browser, that's why everything works there by default).
-
About Web navigation
On web, the history navigation stack is built from scratch because I couldn't handle iframe's internal history the right way.
-
[ x ] On web, user-agent and headers only work when using
SourceType.urlBypass
, and they only have effect the first time being used (view/web.dart
) -
[ x ] On web, it should be possible to send any errors caught when loading an
urlBypass
to a dart callback, which will then be sent through theonWebResourceError
callback, just like on the mobile version (utils/x_frame_options_bypass.dart
) -
[ x ] On web, it should be possible to add a custom proxy list without the js null-checking mess (
utils/x_frame_options_bypass.dart
) -
[ ? ] Eventually (if possible), most if not all properties from
WebSpecificParams
andMobileSpecificParams
should merge and theese two objects may disappear -
[ x ] On mobile, the controller's value's source type becomes out of sync when moving back and forth in history. This happens because the url change is not yet intercepted and set the model accordingly (shouldn't be hard to fix).
-
On mobile, the controller's callJsMethod doesnt throw an error if the operation failed. Instead it only shows the error in console.
-
Add tests
-
List open, there may be others
This package wouldn't be possible without the following:
- webview_flutter for the mobile version
- easy_web_view for ideas and starting point for the web version
- pointer_interceptor for fixing iframe issues when other widgets are on top of it (see above)
- x-frame-bypass for allowing the iframe to bypass websites' X-Frame-Options: deny/same-origin headers, thus allowing us to load any webpage (just like on mobile)
- https://cors.bridged.cc/ for the free CORS proxy
- https://api.codetabs.com/ for the free CORS proxy
- And last but not least, http://deversoft.ro (the company I work for) for motivating me throughout the development process