dvote-js-runtime-flutter

DVote JS runtime for Flutter

The purpose of this component is to overcome the current limitations of the ecosystem available to apps running on Flutter.

The component provides access to a full fledged JS runtime, that will only run explicitly bundled static HTML/JS code.

This is intended as a workaround until Dart has full support for cryptographic and blockchain libraries.

Usage

Check the exampe on example/*.

Within your Flutter code, invoke the available runtime functions as follows.

Add a listener

// listen for post messages coming from the JavaScript side
this.webViewController.addJavaScriptHandler(
    "JS_REQUEST_RESPONSE_CHANNEL", (arguments) => onMessageReceived(arguments));

Trigger an action

final requestId = 1234;
final jsExpression = "myJavascriptFunction('param1', { param2: true }, false)";

await this.webViewController.injectScriptCode('''
    call(() => $jsExpression)
    .then(result => replyMessage($requestId, result))
    .catch(error => replyError($requestId, error))
''');

Handle a response

  onMessageReceived(List<dynamic> arguments) async {
    print(arguments);

    // Expected:
    //  arguments[0] = { id: <int>, error: <bool> }
    //  arguments[1] = <data>
    
    // ...
  }

Customize

• Add your new handler on index.ts
• Declare the function within const handlers: HandlersMap = { ... }
• Run npm run build
• Use dist/runtime.html

Future work

• Provide a dart example
• Provide a dart package to import
• Publish the repo as a package