Flutter - Pass Data Back with .popUntil

Question

I have been using Navigator.pop and passing data back 1 screen with ease. However, if I use Navigator.popUntil, what is an acceptable way to pass an object back to the destination screen?

Answer 1

You can using arguments in RouteSettings to pass data back to a specific Route.

For example:

// in MaterialApp
MaterialApp(
   onGenerateRoute: (settings) {
      switch (settings.name) {
         case '/':
            return MaterialPageRoute(
                     settings: RouteSettings(name: '/', arguments: Map()),  // (1)
                     builder: (_) => HomePage()
                  );
      }
   }
)

// in HomePage
Navigator.of(context).push(MaterialPageRoute(builder: (_) => StuffPage())
                     .then(_) {
                        final arguments = ModalRoute.of(context).settings.arguments as Map;
                        final result = arguments['result'];
                     };

// in StuffPage
Navigator.of(context).popUntil((route) {
   if (route.settings.name == '/') {
      (route.settings.arguments as Map)['result'] = 'something';
      return true;
   } else {
      return false;
   }
});

Note that: you have to initialize arguments or it will be null, that's what is the purpose of (1)