Got it. Yeah, you can hook into GoToAsync as I did, and also provide extension methods/members (depending on your desire) to use your implementation when calling Shell.Current.

I would say that maui provides a basic navigation system, but each app may need its own navigation system, normally an override will be hard to maintain in the library and using composition/proxy is a better approach. If that doesn't work for you either, please open an issue providing more info and maybe a usage sample on what you're trying to archive, that way we can improve the navigation system

I know a "navigation service" should be the way to go, at least aiming not to call Shell.Current in a ViewModel, but since Shell.Current.GoToAsync() is documented everywhere (and so was choosen as the main solution by Maui team, even though it was a terrible idea imho), we know it might be called by a junior-dev at some point in a project and break everything.

You could see my question as "Why does Shell have a virtual method (OnNavigating) that has access to the Current state, the Target state, the OriginalString URL called with eventual string parameters (?a=1&b=2...), the Cancel() way to interrupt the navigation, but has no clue about any other parameter given while navigating?", is there a (good) reason not to expose this?

So, for now, I guess I'll have to move all my redirection handling logic in a "custom navigation service" like you suggested, and replace that logic in my custom Shell class with a simple navigation cancellation (args.Cancel()) followed by an exception's throw (or Debugger.Break(), or logs... anything that'd let (junior) developer know he did something wrong).

@pictos I tried to throw an exception in my OnNavigating override, but I couldn't catch it around the Shell.Current.GoToAsync call, do you know why? Is it because it occurs through an event?

@pictos I tried to throw an exception in my OnNavigating override, but I couldn't catch it around the Shell.Current.GoToAsync call, do you know why? Is it because it occurs through an event?

@lionelmennig, can you expand on that? I didn't follow what you did