How to get previous destination with navigation component?

Question

I have fragments A, B, C, and X where their navigations are as the following.

 A --> X 
 B --> X 
 C --> X

How could I know the information of the last or previous destination in X?

The current destination ID can be found by

Navigation.findNavController(v).getCurrentDestination().getId()

I also tried using getBackStackEntry(int destinationId) but it returns only the topmost NavBackStackEntry for a destination id. In other words, the current destination.

Also getActivity().getSupportFragmentManager().getBackStackEntryCount(); returning 0.

Possible solutions are:

Pass data from A, B, and C to X and identify the previous fragment by checking with that data.
Use shared SharedViewModel.

Is it possible to get the current destination?

why aren't you sending some parameters along with location so that you can know that location belongs to respective fragment. — Sai Jayant, Mar 15 '20 at 07:38
Or you can know on which fragment you were on using these code and change your preference managers LastVistedFragment const see this code https://stackoverflow.com/questions/43207043/check-if-fragment-is-currently-visible-or-no/43658331#43658331 — Sai Jayant, Mar 15 '20 at 07:42
Your solution is good but there should be something for getting backstack from a fragment. @SaiJayant — Patriotic, Mar 15 '20 at 08:46
what are you trying to achieve ? You want info from B to be in X ? — Biscuit, Mar 15 '20 at 12:12
in pop backstack when you will be back to your previous fragment that method i told you also update the current showing fragment — Sai Jayant, Mar 16 '20 at 07:49
I have not found any best solution to get the previous fragment in the currently visible fragment other than sending source id from A, B, and C to X. Thanks for the cooperation. — Patriotic, Mar 16 '20 at 09:18

score 32 · Answer 1 · answered Oct 17 '20 at 22:18

32

Java: Navigation.findNavController(v).getPreviousBackStackEntry().getDestination().getId();

Kotlin: findNavController().previousBackStackEntry?.destination?.id

This should return you the previous destination's id in the 'X' fragment.

answered Oct 17 '20 at 22:18

Mehedi Hasan Shagor

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I think this will be null if popupTo is used, just fyi to others – behelit Aug 23 '23 at 03:34

score -3 · Answer 2 · answered Mar 15 '20 at 11:48

add destination change listener. and compare id with A,B,C of ids on back key press

NavController.OnDestinationChangedListener { controller, destination, arguments ->
    // react on change or 
    //you can check destination.id or destination.label and act based on that
)}

How to get previous destination with navigation component?

2 Answers2