For anyone using `bindToNavigation`, what's the ri...

# compose-web

[Winson Chiu]

For anyone using bindToNavigation, what's the right way to navigate back in common code? Neither popBackStack nor navigateUp replicate browser back for me. Normal navigation does something like:
A -> B -> C -> browser back -> B -> browser back -> A

Whereas the nav methods go:
A -> B -> C -> popBackState/navigateUp -> B -> browser back -> C -> browser back -> B

[Konstantin Tskhovrebov]

because the browser back is NOT the app back stack.
it is just a history of your browser

[Konstantin Tskhovrebov]

and browsers have a unique feature over other platforms: the forward button mind blown

[Konstantin Tskhovrebov]

(I guess the idea of the forward button will help you to understand how it works)

[Winson Chiu]

Hmm... Then how does one implement a back button? Is there a way to invoke browser back from common code?

I don't understand why the existence of forward changes the behavior, since forward is just a replay of the navigation event that took the user to C. Since navigation can build the nav graph from just the string routes, there's no reason any other platform couldn't also record and replay the nav events.

[Konstantin Tskhovrebov]

Apps using the androidx.navigation class integrate with the browser History API to provide a consistent experience when using the browser's back and forward buttons. Whenever you navigate using the navController, a History API entry is added to the browser's history stack. Pressing the back button uses reverse chronological navigation, meaning that the user is taken to the previously visited location that was shown using the navController. This means that if the user pops a page from the back stack and then presses the browser back button the previous page is pushed back onto the stack.

[Winson Chiu]

I mean, I don't actually care what the navigation model is, I just need the arrow back button on the screen to match what the system back does, regardless of what that behavior is.

I guess the answer is that it's not possible and I just need to wrap NavHostController to delegate it to window.history.popState()?

When I'm using an app, which one I hit is basically determined on a whim, and the fact the 2 don't have the same behavior is weird.

[Konstantin Tskhovrebov]

what the system back does

there is no a such thing as "system back"

[Konstantin Tskhovrebov]

only android has a system back event

[Winson Chiu]

System back just describes the user gesture. On Android that's back button/gesture. On browser that's the back button. On desktop that's mouse 4/escape. On iOS that's either back gesture or nonexistent. I just need to make all platforms consistent.

[Konstantin Tskhovrebov]

Browser back button has own behaviour patter and CMP supports it.
if you need to customize it, you are able to do it for your case. just take a look at the CMP implementation. there are no internals usages

[Altynbek Nurtaza]

you could remove the back button altogether, and only let the user use the browser back

[Winson Chiu]

Yeah, but I think I want the user to have the ability to ignore the system specific navigation and use just the app. I ended up with the wrapping approach, calling window.history.back() on wasmJs and popBackStack on other platforms.