MissingPluginException when calling InAppWebViewController

[AlexV525]

Environment

Flutter version: 1.17.0 (stable)
Plugin version: 3.1.0
Android version: Android 10
Device information: Emulator/OnePlus IN2020

Description

Calling any methods in InAppWebViewController throws an unimplement error.

Steps to reproduce

1. Implement a webView widget in some pages.
2. Define method onWebViewCreated and inside this call _webViewController = controller.
3. Call _webViewController.evaluateJavascript(...) or any methods and it throws error.

Images

Stacktrace/Logcat

E/flutter (16827): [ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: MissingPluginException(No implementation found for method evaluateJavascript on channel com.pichillilorenzo/flutter_inappwebview_1)
E/flutter (16827): #0      MethodChannel._invokeMethod (package:flutter/src/services/platform_channel.dart:154:7)
E/flutter (16827): <asynchronous suspension>
E/flutter (16827): #1      MethodChannel.invokeMethod (package:flutter/src/services/platform_channel.dart:329:12)
E/flutter (16827): #2      InAppWebViewController.evaluateJavascript (package:flutter_inappwebview/src/in_app_webview_controller.dart:926:31)
E/flutter (16827): #3      _InAppBrowserPageState.dispose (package:openjmu/widgets/webview/in_app_webview.dart:91:24)
......

[AlexV525]

@pichillilorenzo I think it might be related to id with the channel?

[pichillilorenzo]

This behavior is correct. That happens in your case because you are calling the webview controller method inside the dispose() widget method.
Any webview controller method, such as evaluateJavascript is an async method, so execute asynchronously. It means that when you call a webview controller method at dispose widget time, your webview has already been disposed (it has been removed from the widget tree), so you can't communicate with it, because there isn't any webview anymore.
If you need to set window.onbeforeunload=null with javascript, you need to do it before the dispose widget method is called! For example, you can place it in the onLoadStop method.

[AlexV525]

Okay, but the reason I'm override onBeforeUnload is from another issue, I'll open it later.

BTW, glad to see you coming back after these months. 😄

[github-actions]

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