Android navigation best practice?

Question

I'm currently using navigation version 2.5.2

I've got BottomNavigationView for main menu.

For example,

Main Menu : A, B, C
A(home) can go A -> Aa -> Ab -> D
B can go B -> D
C can go C -> Ca -> D

something like that.

Here's what I have to do,

1. When user click bottom menu, the navigation stack must erase. (ex. When user go A->Aa, and then click B menu at the bottom and back to A, Aa should be erased. User is to see A not Aa)

2. When user click system back button, the stack should be erased one by one. (ex. A->Aa->Ab. When click back, Ab gone and Aa gone and A)

The problem is, When I go B->D and click back(B appeared) and back again(A appeared as it's home). And!!! click B again,

It doesn't even created at the first click, and it is shown from the second click.
No error msg.

mobile_navigation.xml

<navigation xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/mobile_navigation"
    app:startDestination="@id/home">

    <include app:graph="@navigation/home" />

    <fragment
        android:id="@+id/navigation_dashboard"
        android:name="com.example.www.ui.dashboard.DashboardFragment"
        android:label="@string/title_dashboard"
        tools:layout="@layout/fragment_dashboard">
        <action
            android:id="@+id/action_dashboard"
            app:destination="@+id/navigation_seconddash"
            app:popUpTo="@id/navigation_dashboard"
            app:popUpToSaveState="true" />
    </fragment>

    <fragment
        android:id="@+id/navigation_seconddash"
        android:name="com.example.www.ui.home.SecondDashboardFragment"
        android:label="DashBoard2"
        tools:layout="@layout/fragment_seconddashboard"/>

    <fragment
        android:id="@+id/navigation_notifications"
        android:name="com.example.www.ui.notifications.NotificationsFragment"
        android:label="@string/title_notifications"
        tools:layout="@layout/fragment_notifications" />
</navigation>

Dashboard clickevent

binding.btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Navigation.findNavController(view).navigate(R.id.action_dashboard);
            }
        });

It works find when click menu instead of back button.
https://www.youtube.com/shorts/RgyjKWDLx0I
Above is video I recorded cos hard to explain in text.

I've tried deeplink, but it doesn't clear stack. tried different versions, doesn't work.

score 0 · Accepted Answer · answered Oct 29 '22 at 19:11

When you use app:popUpTo="@id/navigation_dashboard", it will delete the dashboard and jumps one back from it, in your case to home. Just delete those 2 lines to avoid that situation.

<fragment
        android:id="@+id/navigation_dashboard"
        android:name="com.example.www.ui.dashboard.DashboardFragment"
        android:label="@string/title_dashboard"
        tools:layout="@layout/fragment_dashboard">
        <action
            android:id="@+id/action_dashboard"
            app:destination="@+id/navigation_seconddash" />
    </fragment>

And for your 2 problems add below line, it will delete your backstack when you click any of the bottom nav items, and the deleting one by one situation works well:

        yourBottomNavView.setOnItemSelectedListener { item ->
            NavigationUI.onNavDestinationSelected(item, yourNavController)
            yourNavController.popBackStack(item.itemId, inclusive = false)
            true
        }

But what's the role of popUpToInclusive? I thought It'd keep dashboard when set it false. but didn't work — user20363150, Oct 31 '22 at 00:09
It's partially true. When you use bottom nav item click events, it's not using that action where you put popupToInclusive, it will use setOnItemSelectedListener. that is why we chose this way. But for example if you want to go from Aa -> Ab and you use popUpTo and popupToInclusive in that action, it will work. For more info on popUpTo see [this](https://developer.android.com/guide/navigation/navigation-navigate#pop) — Mert, Oct 31 '22 at 07:37

Android navigation best practice?

1 Answers1