How to cancel routing go_router in redirection?

Question

How to cancel routing? If user is not premium user, Try to not allow to move to target routing. For example, like below.

redirect: (BuildContext context, GoRouterState state) {
  if (AuthState.of(context).isNotPremiumUser) {
   // cancel routing
  } else {
    return null;
  }   
},

How to do "return false" with go_router?

I did some research but nothing very conclusive.

Answer 1

I found out that If we will throw an exception during redirect, nothing happens

redirect: (BuildContext context, GoRouterState state) {
  if (AuthState.of(context).isNotPremiumUser) {
    throw Exception('Router declined redirect');
  } 
  return null;
}

You can use the same approach for example showing dialog which asks user if he wants to redirect.

redirect: (BuildContext context, GoRouterState state) async {
  if (AuthState.of(context).hasUnfinishedData) {
    final allowed = await showDialog(SomeDialog());

    if(allowed) return null; // Allows for redirection to the specific page may be returned as well from the dialog 
    throw Exception('Router declined redirect');
  } 
  return null;
}

Just return the data from the Dialog like this -

Navigator.of(context).pop(true/false);