conflict with webview_flutter

[3ace]

when I include both webview_flutter and youtube_player_flutter, application would crash upon starts with the following warning and error

objc[44664]: Class FLTCookieManager is implemented in both /Users/ace/Library/Developer/CoreSimulator/Devices/B18AEF78-2279-4A87-AF9C-EC10E395036D/data/Containers/Bundle/Application/7210DA0C-0DBD-40B3-82E4-83D52BA8ADF7/Runner.app/Frameworks/ytview.framework/ytview (0x10c3d8400) and /Users/ace/Library/Developer/CoreSimulator/Devices/B18AEF78-2279-4A87-AF9C-EC10E395036D/data/Containers/Bundle/Application/7210DA0C-0DBD-40B3-82E4-83D52BA8ADF7/Runner.app/Frameworks/webview_flutter.framework/webview_flutter (0x10c3bb250). One of the two will be used. Which one is undefined.
objc[44664]: Class FLTWKNavigationDelegate is implemented in both /Users/ace/Library/Developer/CoreSimulator/Devices/B18AEF78-2279-4A87-AF9C-EC10E395036D/data/Containers/Bundle/Application/7210DA0C-0DBD-40B3-82E4-83D52BA8ADF7/Runner.app/Frameworks/ytview.framework/ytview (0x10c3d8450) and /Users/ace/Library/Developer/CoreSimulator/Devices/B18AEF78-2279-4A87-AF9C-EC10E395036D/data/Containers/Bundle/Application/7210DA0C-0DBD-40B3-82E4-83D52BA8ADF7/Runner.app/Frameworks/webview_flutter.framework/webview_flutter (0x10c3bb2a0). One of the two will be used. Which one is undefined.
objc[44664]: Class FLTWebViewFactory is implemented in both /Users/ace/Library/Developer/CoreSimulator/Devices/B18AEF78-2279-4A87-AF9C-EC10E395036D/data/Containers/Bundle/Application/7210DA0C-0DBD-40B3-82E4-83D52BA8ADF7/Runner.app/Frameworks/ytview.framework/ytview (0x10c3d84a0) and /Users/ace/Library/Developer/CoreSimulator/Devices/B18AEF78-2279-4A87-AF9C-EC10E395036D/data/Containers/Bundle/Application/7210DA0C-0DBD-40B3-82E4-83D52BA8ADF7/Runner.app/Frameworks/webview_flutter.framework/webview_flutter (0x10c3bb2f0). One of the two will be used. Which one is undefined.
objc[44664]: Class FLTWebViewController is implemented in both /Users/ace/Library/Developer/CoreSimulator/Devices/B18AEF78-2279-4A87-AF9C-EC10E395036D/data/Containers/Bundle/Application/7210DA0C-0DBD-40B3-82E4-83D52BA8ADF7/Runner.app/Frameworks/ytview.framework/ytview (0x10c3d84c8) and /Users/ace/Library/Developer/CoreSimulator/Devices/B18AEF78-2279-4A87-AF9C-EC10E395036D/data/Containers/Bundle/Application/7210DA0C-0DBD-40B3-82E4-83D52BA8ADF7/Runner.app/Frameworks/webview_flutter.framework/webview_flutter (0x10c3bb318). One of the two will be used. Which one is undefined.
objc[44664]: Class FLTJavaScriptChannel is implemented in both /Users/ace/Library/Developer/CoreSimulator/Devices/B18AEF78-2279-4A87-AF9C-EC10E395036D/data/Containers/Bundle/Application/7210DA0C-0DBD-40B3-82E4-83D52BA8ADF7/Runner.app/Frameworks/ytview.framework/ytview (0x10c3d8540) and /Users/ace/Library/Developer/CoreSimulator/Devices/B18AEF78-2279-4A87-AF9C-EC10E395036D/data/Containers/Bundle/Application/7210DA0C-0DBD-40B3-82E4-83D52BA8ADF7/Runner.app/Frameworks/webview_flutter.framework/webview_flutter (0x10c3bb390). One of the two will be used. Which one is undefined.
objc[44664]: Class FLTWebViewFlutterPlugin is implemented in both /Users/ace/Library/Developer/CoreSimulator/Devices/B18AEF78-2279-4A87-AF9C-EC10E395036D/data/Containers/Bundle/Application/7210DA0C-0DBD-40B3-82E4-83D52BA8ADF7/Runner.app/Frameworks/ytview.framework/ytview (0x10c3d85b8) and /Users/ace/Library/Developer/CoreSimulator/Devices/B18AEF78-2279-4A87-AF9C-EC10E395036D/data/Containers/Bundle/Application/7210DA0C-0DBD-40B3-82E4-83D52BA8ADF7/Runner.app/Frameworks/webview_flutter.framework/webview_flutter (0x10c3bb458). One of the two will be used. Which one is undefined.
2019-05-04 09:20:00.568482+0700 Runner[44664:362412] libMobileGestalt MobileGestalt.c:890: MGIsDeviceOneOfType is not supported on this platform.
2019-05-04 09:20:00.844000+0700 Runner[44664:362412] You've implemented -[<UIApplicationDelegate> application:performFetchWithCompletionHandler:], but you still need to add "fetch" to the list of your supported UIBackgroundModes in your Info.plist.
2019-05-04 09:20:00.844196+0700 Runner[44664:362412] You've implemented -[<UIApplicationDelegate> application:didReceiveRemoteNotification:fetchCompletionHandler:], but you still need to add "remote-notification" to the list of your supported UIBackgroundModes in your Info.plist.
2019-05-04 09:20:00.845692+0700 Runner[44664:362412] *** Assertion failure in -[FlutterEngine registrarForPlugin:], ../../flutter/shell/platform/darwin/ios/framework/Source/FlutterEngine.mm:560
2019-05-04 09:20:00.917563+0700 Runner[44664:362412] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Duplicate plugin key: FLTWebViewFlutterPlugin'
*** First throw call stack:
(
	0   CoreFoundation                      0x000000010d4296fb __exceptionPreprocess + 331
	1   libobjc.A.dylib                     0x000000010c9cdac5 objc_exception_throw + 48
	2   CoreFoundation                      0x000000010d429482 +[NSException raise:format:arguments:] + 98
	3   Foundation                          0x000000010c41b927 -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 194
	4   Flutter                             0x000000010a5a3d6b -[FlutterEngine registrarForPlugin:] + 269
	5   Runner                              0x000000010a29be1e +[GeneratedPluginRegistrant registerWithRegistry:] + 174
	6   Runner                              0x000000010a29bf18 $s6Runner11AppDelegateC11application_29didFinishLaunchingWithOptionsSbSo13UIApplicationC_SDySo0j6LaunchI3KeyaypGSgtF + 168
	7   Runner                              0x000000010a29c254 $s6Runner11AppDelegateC11application_29didFinishLaunchingWithOptionsSbSo13UIApplicationC_SDySo0j6LaunchI3KeyaypGSgtFTo + 196
	8   UIKitCore                           0x0000000116d3b311 -[UIApplication _handleDelegateCallbacksWithOptions:isSuspended:restoreState:] + 280
	9   UIKitCore                           0x0000000116d3ccad -[UIApplication _callInitializationDelegatesForMainScene:transitionContext:] + 3932
	10  UIKitCore                           0x0000000116d420c6 -[UIApplication _runWithMainScene:transitionContext:completion:] + 1617
	11  UIKitCore                           0x00000001165876d6 __111-[__UICanvasLifecycleMonitor_Compatability _scheduleFirstCommitForScene:transition:firstActivation:completion:]_block_invoke + 904
	12  UIKitCore                           0x000000011658ffce +[_UICanvas _enqueuePostSettingUpdateTransactionBlock:] + 153
	13  UIKitCore                           0x00000001165872ec -[__UICanvasLifecycleMonitor_Compatability _scheduleFirstCommitForScene:transition:firstActivation:completion:] + 236
	14  UIKitCore                           0x0000000116587c48 -[__UICanvasLifecycleMonitor_Compatability activateEventsOnly:withContext:completion:] + 1091
	15  UIKitCore                           0x0000000116585fba __82-[_UIApplicationCanvas _transitionLifecycleStateWithTransitionContext:completion:]_block_invoke + 782
	16  UIKitCore                           0x0000000116585c71 -[_UIApplicationCanvas _transitionLifecycleStateWithTransitionContext:completion:] + 433
	17  UIKitCore                           0x000000011658a9b6 __125-[_UICanvasLifecycleSettingsDiffAction performActionsForCanvas:withUpdatedScene:settingsDiff:fromSettings:transitionContext:]_block_invoke + 576
	18  UIKitCore                           0x000000011658b610 _performActionsWithDelayForTransitionContext + 100
	19  UIKitCore                           0x000000011658a71d -[_UICanvasLifecycleSettingsDiffAction performActionsForCanvas:withUpdatedScene:settingsDiff:fromSettings:transitionContext:] + 223
	20  UIKitCore                           0x000000011658f6d0 -[_UICanvas scene:didUpdateWithDiff:transitionContext:completion:] + 392
	21  UIKitCore                           0x0000000116d409a8 -[UIApplication workspace:didCreateScene:withTransitionContext:completion:] + 514
	22  UIKitCore                           0x00000001168f7dfa -[UIApplicationSceneClientAgent scene:didInitializeWithEvent:completion:] + 361
	23  FrontBoardServices                  0x0000000118d71125 -[FBSSceneImpl _didCreateWithTransitionContext:completion:] + 448
	24  FrontBoardServices                  0x0000000118d7aed6 __56-[FBSWorkspace client:handleCreateScene:withCompletion:]_block_invoke_2 + 283
	25  FrontBoardServices                  0x0000000118d7a700 __40-[FBSWorkspace _performDelegateCallOut:]_block_invoke + 53
	26  libdispatch.dylib                   0x0000000110db5db5 _dispatch_client_callout + 8
	27  libdispatch.dylib                   0x0000000110db92ba _dispatch_block_invoke_direct + 300
	28  FrontBoardServices                  0x0000000118dac146 __FBSSERIALQUEUE_IS_CALLING_OUT_TO_A_BLOCK__ + 30
	29  FrontBoardServices                  0x0000000118dabdfe -[FBSSerialQueue _performNext] + 451
	30  FrontBoardServices                  0x0000000118dac393 -[FBSSerialQueue _performNextFromRunLoopSource] + 42
	31  CoreFoundation                      0x000000010d390be1 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
	32  CoreFoundation                      0x000000010d390463 __CFRunLoopDoSources0 + 243
	33  CoreFoundation                      0x000000010d38ab1f __CFRunLoopRun + 1231
	34  CoreFoundation                      0x000000010d38a302 CFRunLoopRunSpecific + 626
	35  GraphicsServices                    0x0000000111ba92fe GSEventRunModal + 65
	36  UIKitCore                           0x0000000116d43ba2 UIApplicationMain + 140
	37  Runner                              0x000000010a29c3f8 main + 72
	38  libdyld.dylib                       0x0000000110e2a541 start + 1
	39  ???                                 0x0000000000000001 0x0 + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException

I had to remove webview_flutter to be able to run the application.

I only tested this problem on iOS using simulator.

[GeertJohan]

A related problem occurs on android, where the following exception is thrown and the application exits before first frame render.
E/AndroidRuntime( 6955): java.lang.RuntimeException: Unable to start activity ComponentInfo{my.app/my.app.MainActivity}: java.lang.IllegalStateException: Plugin key io.flutter.plugins.webviewflutter.WebViewFlutterPlugin is already in use

[sarbagyastha]

Sorry for late response 😐, but this plugin has in-built webview plugin, so no need to add webview plugin separately.

[GeertJohan]

@sarbagyastha But my app also uses the webview directly. Can it use the forked version, will that be kept up-to-date with the latest version of webview_flutter? Can the changes in this plugin's fork of webview_flutter be merged upstream so it no longer requires the fork?

[Xoshbin]

D8: Program type already present: io.flutter.plugins.webviewflutter.BuildConfig

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:transformClassesWithMultidexlistForDebug'.
> com.android.build.api.transform.TransformException: Error while generating the main dex list:
  Error while merging dex archives: 
  Learn how to resolve the issue at https://developer.android.com/studio/build/dependencies#duplicate_classes.
  Program type already present: io.flutter.plugins.webviewflutter.BuildConfig

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 10s
Finished with error: Gradle task assembleDebug failed with exit code 1

I'm using webview_flutter: ^0.3.6 in my app but when having both of them it gives the above error. and when I remove the webview_flutter: ^0.3.6 it gives error because my app needs it.

[sarbagyastha]

@GeertJohan yes the forked version will be kept up-to-date for major updates and performance improvements. Yes, it could be merged but takes a long time to get merge, there are currently many pending webview_flutter PRs in project tracking.

[sarbagyastha]

@Xoshbin , will be updating the plugin tonight, where access to in-built webview will be exported.

[Xoshbin]

@sarbagyastha Thanks I will wait for it then :)

[sarbagyastha]

Version 1.1.1 addresses the issue.

[Xoshbin]

It's not working for me yet, I did remove the webview from dependencies it still gives error, and when I add it it still gives the same error above.

[sarbagyastha]

did you perform full build ?
Also try running flutter clean

[Xoshbin]

Yes I did a full build, and flutter clean with and without the webview_flutter

[sarbagyastha]

Also, If you're using Android Studio, please try invalidating cache. Or perform gradlew clean.
This might be due to leftover of webview_flutter plugin.

[Xoshbin]

Do I have to keep the webview_flutter in the dependancies or remove it?

[Xoshbin]

I did that too, still not working!

[3ace]

I'm able to use the built in WebView using this import statement

import 'package:ytview/ytview.dart';

I think this should be mentioned in the Readme file

[sarbagyastha]

@Xoshbin @3ace You'll need to remove webview_flutter. And with the latest update
import 'package:youtube_player_flutter/youtube_player_flutter.dart';
includes WebView widget.
It's mentioned in Note section of readme.

[Xoshbin]

@sarbagyastha Thanks it's working now.

[adrianvintu]

Can you please make a big note about this in the readme?

And also add the import as specified by @3ace ?

import 'package:ytview/ytview.dart';

This was a very difficult issue to debug.

Maybe actually add a link to this page in the readme?

I find that the existing text is not very clear, especially for someone new to Flutter.

Existing text:
The plugin causes conflict with webview_flutter plugin as this plugin already contains webview as its dependency. So there is no need of separately adding webview_flutter. You can use WebView from the plugin itself.

Proposal text:

Conflict with webview

You may get an exception like:
program type already present: io.flutter.plugins.webviewflutter
or
Plugin key io.flutter.plugins.webviewflutter.WebViewFlutterPlugin is already in use

The plugin causes conflict with webview_flutter plugin as this plugin already contains webview as its dependency. So there is no need of separately adding webview_flutter. You can use WebView from the plugin itself.

This means:

1. you delete/comment out

dependencies:
  webview_flutter: ^0.3.0

2. you use import 'package:ytview/ytview.dart';
3. optionally, see this ticket for more information

---

How does this text sound to you?

Thank you for the great work, by the way!

[yamarkz]

thanks! Great work 😸

[ziggycrane]

When I import
import 'package:youtube_player_flutter/youtube_player_flutter.dart';
and remove "webview_flutter: 0.3.19+7", install all the packages and even flutter clean - it does not work.

It throws an error that - The method "WebView" is not defined.

[srinivasanrsp]

YouTube player plugin uses another plugin webview_media and that uses webview_flutter plugin, so use following import the error should be gone

import 'package:webview_media/webview_flutter.dart'

[jameskaguo777]

import 'package:webview_media/webview_flutter.dart'

This is the most correct Answer.

[NtemKenyor]

I had the same issue using webview_flutter and youtube_player_flutter. I used the solution by @srinivasanrsp. It works.

1. Remove the webview_flutter package from the pubspec.yaml file
2. Use import 'package:webview_media/webview_flutter.dart';

This works just fine.