[Deprecated] Flutter Go Router: Async Await and Return Data from Previous Screen

Deprecated!

Since go_router version https://pub.dev/packages/go_router/changelog#650 they support return value on pop, so you can use it as usual as example below.

Background

In the Navigator, we can use async await. We can wait until the previous page is popped and do something with value from that screen. For example, we will refresh the list page after we edit the data in edit page.

class Page1 extends Stateless{

  ....
  TextButton(
  onPressed:() async {
      /// Will get return boolean data
	    final result = await Navigator.pushNamed("page2") as bool;
			if (result){
			...
			}
	  }
  )
}

---

class Page2 extends Stateless{

  ....
  TextButton(
  onPressed:() async {
      /// return true to Page1
	    Navigator.pop(context,true);
	  }
  )
}

But, In the go_router for context.goNamed or context.pushNamed is return void

It's different with Navigator.pushNamed it's using Future and T object, so we can return await and T object data when you call Navigator.pop(context,T)

Popping and return value in Go Router

In the go_router you can do this:

class Page1 extends Stateless{

  ....
  TextButton(
  onPressed:() async {
      /// Will get return boolean data
	    context.pushNamed(
		    "page2",
		    /// this will be triggerd when `result.call(true);` is called
		    /// on the Page2
		    extra:(result){
			    if (result){
					...
					}
		    }
	    );
	  }
  )
}

---

class Page2 extends Stateless{
  const Page2({super.key, required this.result});

  // create callback and will return bool
  final Function(bool) result;

  ....
  TextButton(
  onPressed:() async {
	    context.pop();
	    /// trigger extra on Page1
	    result.call(true);
	  }
  )
}

For the bool you can replace it with what data you need, for Example String, Object, etc.