Question 1

What is the difference between Navigator 1.0 and 2.0?

Accepted Answer

The difference is imperative versus declarative. In 1.0 you issue commands: push, pop — which works perfectly for simple flows. In 2.0 you describe the app's state, usually a URL, and the stack is derived from it — which is what deep links, web URL sync and conditional redirects need. State the practical reality too: the raw Navigator 2.0 API (RouterDelegate, RouteInformationParser) is complex enough that real projects almost always use a package like go_router. That last sentence moves the answer from "read about it" to "shipped it".

Question 2

How do you implement authentication guarding in navigation?

Accepted Answer

In the central redirect function — the single point that runs on every navigation. The logic: if the user is not signed in and is heading for a protected route, redirect to /login and keep the target in a query parameter so I can return them afterwards. The inverse matters too: a signed-in user heading to /login goes to the main screen. The advantage over per-screen checks is that you cannot forget the guard when adding a new screen — a real security difference. I would add that refreshListenable makes the router re-evaluate when auth state changes.

Question 3

Are there downsides to using go_router?

Accepted Answer

Yes, and answering honestly lands well. (1) An extra dependency and learning cost — on a small three-or-four-screen app Navigator.push is simpler and more readable. (2) String-based paths — a typo like context.go('/oders/42') only surfaces at runtime; code generation fixes that but brings its own complexity. (3) Debugging — once the redirect chain grows it gets hard to see which redirect fired. My criterion: deep links, web support or conditional redirects — yes; a simple mobile flow — plain Navigator is enough.

Question 4

Why must the URL and app state stay in sync on the web?

Accepted Answer

Because web users expect different things: copying a link and sending it, opening it in a new tab, using the browser back and forward buttons, refreshing the page. If the URL does not reflect state, all of that breaks — the user is on /orders/42, refreshes, and lands on the home screen. Declarative routing solves it because the URL is the source of truth and the stack is built from it. Contrast it with mobile: there is no visible URL, so the problem stays hidden — but deep-link support needs the same mechanism, which is why the work pays off on both platforms.

go_router and deep linking

📚 Sources and documentation