iosWebViewFix/example/lib/headless_in_app_webview.screen.dart

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_inappwebview/flutter_inappwebview.dart';

import 'main.dart';

class HeadlessInAppWebViewExampleScreen extends StatefulWidget {
  @override
  _HeadlessInAppWebViewExampleScreenState createState() =>
      new _HeadlessInAppWebViewExampleScreenState();
}

class _HeadlessInAppWebViewExampleScreenState extends State<HeadlessInAppWebViewExampleScreen> {
  HeadlessInAppWebView headlessWebView;
  String url = "";

  @override
  void initState() {
    super.initState();

    headlessWebView = new HeadlessInAppWebView(
      initialUrl: "https://flutter.dev/",
      initialOptions: InAppWebViewGroupOptions(
        crossPlatform: InAppWebViewOptions(
          debuggingEnabled: true,
        ),
      ),
      onWebViewCreated: (controller) {
        print('HeadlessInAppWebView created!');
      },
      onConsoleMessage: (controller, consoleMessage) {
        print("CONSOLE MESSAGE: " + consoleMessage.message);
      },
      onLoadStart: (controller, url) async {
        print("onLoadStart $url");
        setState(() {
          this.url = url;
        });
      },
      onLoadStop: (controller, url) async {
        print("onLoadStop $url");
        setState(() {
          this.url = url;
        });
      },
      onUpdateVisitedHistory: (InAppWebViewController controller, String url, bool androidIsReload) {
        print("onUpdateVisitedHistory $url");
        setState(() {
          this.url = url;
        });
      },
    );
  }

  @override
  void dispose() {
    super.dispose();
    headlessWebView.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
            title: Text(
          "HeadlessInAppWebView",
        )),
        drawer: myDrawer(context: context),
        body: SafeArea(
          child: Column(children: <Widget>[
            Container(
            padding: EdgeInsets.all(20.0),
            child: Text(
                "CURRENT URL\n${(url.length > 50) ? url.substring(0, 50) + "..." : url}"),
          ),
          Center(
            child: RaisedButton(
              onPressed: () async {
                await headlessWebView.dispose();
                await headlessWebView.run();
              },
              child: Text("Run HeadlessInAppWebView")),
          ),
          Center(
            child: RaisedButton(
              onPressed: () async {
                try {
                  await headlessWebView.webViewController.evaluateJavascript(source: """console.log('Here is the message!');""");
                } on MissingPluginException catch(e) {
                  print("HeadlessInAppWebView is not running. Click on \"Run HeadlessInAppWebView\"!");
                }
              },
              child: Text("Send console.log message")),
          ),
          Center(
            child: RaisedButton(
              onPressed: () {
                headlessWebView.dispose();
              },
              child: Text("Dispose HeadlessInAppWebView")),
          )
        ])
      )
    );
  }
}