◆ Sparround

Navigation basics

Navigation in Flutter is a stack model: the Navigator pushes screens on top of each other, and pop removes the topmost one.

  • Navigator.push(context, MaterialPageRoute(builder: ...)) adds a screen
  • Navigator.pop(context) goes back, and its second argument returns a value
  • pushReplacement replaces the current screen (login → home, say)
  • pushAndRemoveUntil clears the stack and opens a new screen (on sign-out)

push returns a `Future`, which is easy to miss: it completes with whatever the screen passes to pop.

There are two ways to pass data between screens:

  • Constructor — MaterialPageRoute(builder: (_) => DetailScreen(id: order.id)). Type-safe, and it should be your first choice
  • Named route with arguments — Navigator.pushNamed(context, '/detail', arguments: id). It gives you a central route table, but arguments is Object? and needs a cast

That missing type safety is a genuine problem — which is exactly why packages like go_router offer typed parameters.

Interview tip. The Future returned by push comes up often: "how do you get a result back from a picker screen?" The answer: final result = await Navigator.push<Item>(...), with Navigator.pop(context, selectedItem) on the second screen. The result can be null when the user backs out — mentioning that completes the answer.

📚 Sources and documentation