<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>InAppWebViewJavaScriptHandlerTest</title> </head> <body> <h1>InAppWebViewJavaScriptHandlerTest</h1> <script> window.addEventListener("flutterInAppWebViewPlatformReady", function(event) { window.flutter_inappwebview.callHandler('handlerFoo').then(function(result) { window.flutter_inappwebview.callHandler('handlerFooWithArgs', 1, true, ['bar', 5], {foo: 'baz'}, result).then(function(result) { }); }); }); </script> </body> </html>