registerWebServiceExtension function Null safety

void registerWebServiceExtension(
  1. Future<Map<String, dynamic>> callback(
    1. Map<String, String>
    )
)

The web implementation of registerWebServiceExtension.

Adds a hidden window.$flutterDriver JavaScript function that's called by FlutterWebDriver to fulfill FlutterDriver commands.

See also:

  • _extension_io.dart, which has the dart:io implementation

Implementation

void registerWebServiceExtension(Future<Map<String, dynamic>> Function(Map<String, String>) callback) {
  js_util.setProperty(html.window, r'$flutterDriver', allowInterop((dynamic message) async {
    try {
      final Map<String, dynamic> messageJson = jsonDecode(message as String) as Map<String, dynamic>;
      final Map<String, String> params = messageJson.cast<String, String>();
      final Map<String, dynamic> result = await callback(params);
      context[r'$flutterDriverResult'] = json.encode(result);
    } catch (error, stackTrace) {
      // Encode the error in the same format the FlutterDriver extension uses.
      // See //packages/flutter_driver/lib/src/extension/extension.dart
      context[r'$flutterDriverResult'] = json.encode(<String, dynamic>{
        'isError': true,
        'response': '$error\n$stackTrace',
      });
    }
  }));
}