Navigation Component backstack behavior

Navigation Component is great, but the backstack behavior can be confusing at first.

I had a flow where users go from A -> B -> C, and I wanted them to go back to A when they finish C, skipping B. The default behavior would take them back through B.

You can use popUpTo and popUpToInclusive to control this:

<action
    android:id="@+id/action_c_to_a"
    app:destination="@id/fragment_a"
    app:popUpTo="@id/fragment_a"
    app:popUpToInclusive="false" />

This pops everything up to fragment A (but not including A), so the backstack becomes just A.

But here's what tripped me up - if you set popUpToInclusive="true", it will also pop A, leaving you with whatever was before A in the backstack. Usually you want false unless you're doing a complete reset.

Also, if you're using navigateUp() programmatically, it respects the backstack, but popBackStack() gives you more control. You can pop to a specific destination or pop multiple entries at once.

One more thing - the backstack is managed automatically, but if you're doing deep linking or handling back button presses manually, make sure you understand what's in the backstack at that point.

Thanks for reading! Check out more posts on the blog if you'd like.