kotlinlang #navigation-architecture-component

Hi. I want to build a kind of master detail view when the screen is big enough. does anyone have experience using navigation component (single activity) with this layout. 1. how do i get the navController in both fragments 2. how is the xml layout lookin g (e.g. navController) 3. which structure would be best if we need some screens with/without toolbar and/or tablayout with viewpager • activity (with toolbar and or tablayout -> hide/show) -> masterFragment | detailFragment • activity -> containerfragment (with toolbar and or tablayout) -> masterFragment | detailFragment thanks for the help / discussion

Archie

07/27/2020, 9:40 AM

Whats the suggested way to do Inter-Module Navigation? I have a situation like this: Module A contains nav_graph_a.xml

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<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/someId">
    ....
    <fragment
        android:id="@+id/someFragmentInModuleA"
        android:name="ModuleAFragment">
        <action
            android:id="@+id/action_to_ModuleBFragment_which_is_in_Module_B"
            app:destination="@id/someFragmentInModuleB"/> // But id dont have a reference to this ID so its red
    </fragment>
    ....
</navigation>

Module B contains nav_graph_b.xml

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<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/someId">
    ....
    <fragment
        android:id="@+id/someFragmentInModuleB"
        android:name="ModuleBFragment">
        
    </fragment>
    ....
</navigation>

I can't have ModuleA depende on ModuleB or vice versa... What can you guys suggest? I know there is a

Dynamic Navigation

but I'm not sure if I should use it for my usecase as its advertised as solution for

Dynamic Feature Modules

to which my modules are not.

George Theocharis

07/30/2020, 10:33 AM

Hello all 👋 Quick question does the navigation component support shared element transitions from fragment to a second activity?

Petru

08/05/2020, 10:02 AM

Hello I was trying to use a headless fragment as the startDestination of a nested graph This fragment containing some routing logic (hidden from the user, basically check if device has camera) to then navigate to other 2 possible fragments (check needed in many places, don't want to duplicate code) This works great and I see it as quite elegant, The issue comes when using enter/exit animations: Can that headless fragment get the animations from the action that started it and use the same for the fragment that it starts? So that this routing would be totally transparent to the user?

Ramadan Al.

09/25/2020, 4:28 PM

Hello everyone, I want to launch a fragment in nested nav graph from push notification using navDeepBuilder. It works fine if the app in the foreground but if the app in the background it just opens mainActivity. Any suggestions??

Joao Birk

10/06/2020, 2:39 PM

Hi there! I'm having an issue after we moved to navigation components. We are doing a lot of stuff in the

onCreateView

, that needs to be refactored, but for now we are keeping a reference to the view:

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private lateinit var binding: FragmentAbcBinding

and doing the following in that method:

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override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
    if (!::binding.isInitialized) {
        binding = DataBindingUtil.inflate(inflater, R.layout.fragment_abc, container, false)

        
    } else {
        val rootView = binding.root

        (rootView.parent as? ViewGroup)?.removeView(rootView)
    }

    return binding.root
}

But for some reason, in some devices we are seeing the following crash:

*java.lang.IllegalStateException*:

at android.view.ViewGroup.addViewInner (ViewGroup.java:5958)

at android.view.ViewGroup.addView (ViewGroup.java:5777)

at androidx.fragment.app.FragmentContainerView.addView (FragmentContainerView.java:6)

Basically the

binding.root

still has a view being returned when calling

binding.root.getParent()

Unfortunately the stack trace doesn't tell me which fragment is throwing such exception. We are using the https://github.com/android/architecture-components-samples/blob/master/NavigationAdvancedSample/app/src/main/java/com/example/android/navigationadvancedsample/NavigationExtensions.kt Has anyone here faced this issue?

George Theocharis

10/14/2020, 3:23 PM

Have you ever experienced popupto inclusive working programmatically but not when on xml?

🚫 1

kevin.cianfarini

10/15/2020, 8:14 PM

Is it possible to have safe args generate internal code for passing data around? We're getting compiler errors because a lot of our code is internal in its own module. My searching has turned nothing up

Geert

11/09/2020, 9:08 AM

I’m getting this weird error because my Mac added a hidden .DS_Store file for the safe arguments… Why isn’t this handled by Android Studio? This means we can’t open the navigation folder…:

Geert

11/09/2020, 9:08 AM

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> Task :app:generateSafeArgsDebug FAILED
Caching disabled for task ':app:generateSafeArgsDebug' because:
  Build cache is disabled
Task ':app:generateSafeArgsDebug' is not up-to-date because:
  Input property 'navigationFiles' file /Users/geert/Desktop/MedxpertNav/app/src/main/res/navigation/.DS_Store has been added.
  Input property 'navigationFiles' file /Users/geert/Desktop/MedxpertNav/app/src/main/res/navigation/mobile_navigation.xml has changed.
:app:generateSafeArgsDebug (Thread[Execution worker for ':' Thread 4,5,main]) completed. Took 0.028 secs.
:snomed:bundleLibCompileToJarDebug (Thread[Execution worker for ':' Thread 11,5,main]) completed. Took 0.837 secs.
:zorgkluisui:kaptDebugKotlin (Thread[Execution worker for ':' Thread 2,5,main]) completed. Took 10.228 secs.

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:generateSafeArgsDebug'.
> org.xmlpull.v1.XmlPullParserException: only whitespace content allowed before start tag and not \u0 (position: START_DOCUMENT seen \u0... @1:1) 

* Try:
Run with --debug option to get more log output. Run with --scan to get full insights.

* Exception is:
org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':app:generateSafeArgsDebug'.
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.lambda$executeIfValid$1(ExecuteActionsTaskExecuter.java:208)
        at org.gradle.internal.Try$Failure.ifSuccessfulOrElse(Try.java:263)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeIfValid(ExecuteActionsTaskExecuter.java:206)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:187)
        at org.gradle.api.internal.tasks.execution.CleanupStaleOutputsExecuter.execute(CleanupStaleOutputsExecuter.java:114)
        at org.gradle.api.internal.tasks.execution.FinalizePropertiesTaskExecuter.execute(FinalizePropertiesTaskExecuter.java:46)
        at org.gradle.api.internal.tasks.execution.ResolveTaskExecutionModeExecuter.execute(ResolveTaskExecutionModeExecuter.java:62)
        at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:57)
        at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:56)
        at org.gradle.api.internal.tasks.execution.CatchExceptionTaskExecuter.execute(CatchExceptionTaskExecuter.java:36)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.executeTask(EventFiringTaskExecuter.java:77)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:55)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:52)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:409)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:399)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor$1.execute(DefaultBuildOperationExecutor.java:157)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:242)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:150)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor.call(DefaultBuildOperationExecutor.java:94)
        at org.gradle.internal.operations.DelegatingBuildOperationExecutor.call(DelegatingBuildOperationExecutor.java:36)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter.execute(EventFiringTaskExecuter.java:52)
        at org.gradle.execution.plan.LocalTaskNodeExecutor.execute(LocalTaskNodeExecutor.java:41)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:372)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:359)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:352)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:338)
        at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.lambda$run$0(DefaultPlanExecutor.java:127)
        at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.execute(DefaultPlanExecutor.java:191)
        at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.executeNextNode(DefaultPlanExecutor.java:182)
        at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.run(DefaultPlanExecutor.java:124)
        at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:64)
        at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:48)
        at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:56)
Caused by: org.gradle.internal.UncheckedException: org.xmlpull.v1.XmlPullParserException: only whitespace content allowed before start tag and not \u0 (position: START_DOCUMENT seen \u0... @1:1) 

* Get more help at <https://help.gradle.org>

BUILD FAILED in 4m 54s
108 actionable tasks: 21 executed, 87 up-to-date
MacBookPro:MedxpertNav (nav) $

Vivekpanchal64

11/21/2020, 11:45 AM

can anyone explain me how do i define default animations for navigation for navigation components..!! instead of keep defining animation for each nav action ??

Kshitij Patil

12/07/2020, 7:19 PM

Im passing navigation argument from one fragment to other. I want to fetch some details based on the given args, in the ViewModel of destination fragment. This results in modification to the state in viewmodel which is being observed by the fragment. Doing so causes

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java.lang.IllegalArgumentException: No destination with ID 2131362278 is on the NavController's back stack. The current destination is Destination(ai.adagrad.gateguard:id/navigation_add_visitor) label=AddVisitorFragment class=ai.adagrad.gateguard.addvisitor.AddVisitorFragment
        at androidx.navigation.NavController.getBackStackEntry(NavController.java:1295)
       $inlined$navGraphViewModels$1.invoke(NavGraphViewModelLazy.kt:56)
        $inlined$navGraphViewModels$1.invoke(NavGraphViewModelLazy.kt)
        at kotlin.SynchronizedLazyImpl.getValue(LazyJVM.kt:74)
        $inlined$navGraphViewModels$2.invoke(NavGraphViewModelLazy.kt:59)
    $inlined$navGraphViewModels$2.invoke(NavGraphViewModelLazy.kt)
        at androidx.lifecycle.ViewModelLazy.getValue(ViewModelProvider.kt:53)
        at androidx.lifecycle.ViewModelLazy.getValue(ViewModelProvider.kt:41)
        at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
        at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
        at androidx.lifecycle.DispatchQueue.drainQueue(DispatchQueue.kt:75)
        at androidx.lifecycle.DispatchQueue.enqueue(DispatchQueue.kt:107)
        at androidx.lifecycle.DispatchQueue.runOrEnqueue(DispatchQueue.kt:97)
        at androidx.lifecycle.PausingDispatcher.dispatch(PausingDispatcher.kt:182)
        at kotlinx.coroutines.internal.DispatchedContinuationKt.resumeCancellableWith(DispatchedContinuation.kt:305)
        at kotlinx.coroutines.intrinsics.CancellableKt.startCoroutineCancellable(Cancellable.kt:30)
        at kotlinx.coroutines.intrinsics.CancellableKt.startCoroutineCancellable$default(Cancellable.kt:27)
        at kotlinx.coroutines.BuildersKt__Builders_commonKt.withContext(Builders.common.kt:167)
        at kotlinx.coroutines.BuildersKt.withContext(Unknown Source)
        at androidx.lifecycle.PausingDispatcherKt$whenStateAtLeast$2.invokeSuspend(PausingDispatcher.kt:162)
        at androidx.lifecycle.PausingDispatcherKt$whenStateAtLeast$2.invoke(PausingDispatcher.kt)
        at kotlinx.coroutines.intrinsics.UndispatchedKt.startUndispatchedOrReturn(Undispatched.kt:91)
        at kotlinx.coroutines.BuildersKt__Builders_commonKt.withContext(Builders.common.kt:161)
        at kotlinx.coroutines.BuildersKt.withContext(Unknown Source)
        at androidx.lifecycle.PausingDispatcherKt.whenStateAtLeast(PausingDispatcher.kt:156)
        at androidx.lifecycle.PausingDispatcherKt.whenCreated(PausingDispatcher.kt:42)
        at androidx.lifecycle.LifecycleCoroutineScope$launchWhenCreated$1.invokeSuspend(Lifecycle.kt:74)
        at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
        at kotlinx.coroutines.internal.DispatchedContinuationKt.resumeCancellableWith(DispatchedContinuation.kt:342)
        at kotlinx.coroutines.intrinsics.CancellableKt.startCoroutineCancellable(Cancellable.kt:30)
        at kotlinx.coroutines.intrinsics.CancellableKt.startCoroutineCancellable$default(Cancellable.kt:27)
        at kotlinx.coroutines.CoroutineStart.invoke(CoroutineStart.kt:109)
        at kotlinx.coroutines.AbstractCoroutine.start(AbstractCoroutine.kt:158)
        at kotlinx.coroutines.BuildersKt__Builders_commonKt.launch(Builders.common.kt:56)
        at kotlinx.coroutines.BuildersKt.launch(Unknown Source)
        at kotlinx.coroutines.BuildersKt__Builders_commonKt.launch$default(Builders.common.kt:49)
        at kotlinx.coroutines.BuildersKt.launch$default(Unknown Source)
        at androidx.lifecycle.LifecycleCoroutineScope.launchWhenCreated(Lifecycle.kt:73)
        at androidx.fragment

This exception. Without updating any state, navigation works fine and I'm even able to view the argument on the UI, but the moment I pass it to the ViewModel, crash occurs Edit: To give you more context, this fragment is hosting a FragmentContainerView

Aness Iqbal

12/13/2020, 4:29 PM

Hi there, I need to go to particular destination/dialog in my app when ever the user receives HTTP error 401. Is it possible to observe/post that error from simple kotlin class to a Host activity, doesn't matter whichever fragment I am on? I do not want to abuse live data for this as this condition may only occur sometimes. Any kind help will be appreciated.

Aness Iqbal

12/18/2020, 9:28 PM

I have A, B, C, D fragments on Activity 1. When I want to navigate to Activity 2 from Fragment D, I also needed to clear the nav back stack from D till A at that point. Also, Activity 2 will return some results to Activity 1. In fragment D, I am calling popBackStack before start activity for result as

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view?.findNavController()?.popBackStack(R.id.dashboard_fragment, false) // pop the stack till home.

and doing this right after above line

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activity?.startActivityForResult(intent, HomeActivityRequestCode)

the problem here is I get view of Fragment A (dashboard fragment) for a second while starting Activity 2 from Fragment D. How can I avoid the view of Fragment A when going from Fragment D to Activity 2. Note: I am using activity for results currently if there is some better approach other than that, please do help me with that.

SimonT

03/04/2021, 9:40 PM

Hello, I would like to ask if do you know of an example of jetpack navigation passing arguments between two nav graphs. For example I did fragment1 action with a string to fragment2 and that works, but when I try to put fragment1 in navGraph 1 and fragment2 in navGraph 2 and include them in a main nav graph, I'm not managing to make the safe args plugin work.

solidogen

05/24/2021, 12:59 PM

I have a usual flow of fragment A->B->C I have a shortcut from A -> C, skipping B - but I would like to get to popup to B while backpressing from C. So I need either setting manual backstack like A -> B,C - or some like of deep link, but I can’t find any real examples

Tepes Lucian Victor

06/22/2021, 3:16 PM

just started experimenting with multiple backstack and i run into https://github.com/android/architecture-components-samples/issues/1005 - does anyone know if that’s intended or not?

sunnat629

07/30/2021, 3:47 PM

I have a question.

BottomNavigationView

has 3 tabs. But the main problem is tab 2 and tab 3 destroys when I click another tab. But Tab1 is not destroyed unless the MainActivity is destroyed. Is this normal? But why?

fragmentVersion = "1.4.0-alpha05"

and

navVersion = "2.4.0-alpha05"

Vyshas

08/02/2021, 8:57 PM

How do we track bottom menu nav items clicks only when bottom menu items are clicked ? Currently using Bottom navigation view 2.4.0-alpha05, we have a use case for tracking bottom nav clicks for analytics and bottom nav is set like below

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binding.bottomNavigationView.setupWithNavController(navController)

If I use below, then bottom nav selection stops working.

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binding.bottomNavigationView.setOnItemSelectedListener { 
            //track clicks

            true
        }

Tepes Lucian Victor

09/03/2021, 4:11 PM

I’ve started a new project using navigation component multiple backstack support and i’ve hit an issue with having an auth subgraph

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<?xml version="1.0" encoding="utf-8"?>
<navigation xmlns:android="<http://schemas.android.com/apk/res/android>"
    xmlns:app="<http://schemas.android.com/apk/res-auto>"
    android:id="@+id/main"
    app:startDestination="@id/graph1">

    <include app:graph="@navigation/graph1" />
    <include app:graph="@navigation/graph2" />
    <include app:graph="@navigation/graph3" />

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

    <action
        android:id="@+id/action_to_auth"
        app:destination="@id/auth"
        app:popUpTo="@id/graph1"
        app:popUpToInclusive="true"
        app:launchSingleTop="true" />

    <action
        android:id="@+id/action_to_main"
        app:destination="@id/graph1"
        app:popUpTo="@id/auth"
        app:popUpToInclusive="true"
        app:launchSingleTop="true" />
</navigation>

When starting the app if the user is logged out i redirect to auth flow using the `action_to_auth`and when he logs out, i’m calling

navigate(R.id.action_to_auth)

. The issue with multiple backstacks is that saved stacks aren’t cleared and there is no way to query what back stacks were previously saved into the fragment manager.

Apex

09/10/2021, 5:14 PM

Does anyone have a good sample for handling User login/ register with Nav component? The docs recommend having a fixed start destination and applying authentication on pages that need it

Apex

09/10/2021, 5:15 PM

But I don't want user to access any part of the app without authentication

Vivekpanchal64

11/30/2021, 5:06 AM

i have a login graph where once user logged in i navigate him to home screen. • but when he skip login and move to home screen and tries any user related action i want him to go back to login but once login i want him to stay at the page he was looking into. can anyone help me out how should i do this ?

Cristina Uroz

05/29/2022, 1:47 PM

Hello everyone! A question relate to compose navigation: has anyone had trouble with navigation on a Xiaomi phone? I have a MIUI 13 that doesn’t complete the start navigation flow until you touch the screen

Dhaval Gondaliya

09/23/2022, 11:24 AM

anyone know how to use

findNavController()

Application

class?

Rafael Costa

10/02/2022, 9:13 PM

Hi all 👋 Could someone please explain to me how it is possible that ViewModels are not cleared on multi back stack scenario, since the corresponding NavBackStackEntries are popped from back stack, I really thought that would be the case, but I was surprised to find it isn't. I thought the state restoration would rely on the SavedStateHandle bundle to do it's thing, but seems like that's not the case, VMs are not even cleared.

why

04/12/2023, 1:54 PM

Hello there. Is it possible to save the state of a nested navigation without popping up to start destination? I'm trying to implement a multi-stack navigation across bottomBar tabs. (navigation in Compose)

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navOptions {
                popUpTo(navController.graph.findStartDestination().id) {
                    saveState = true
                }
                restoreState = true
            }

Vivekpanchal64

05/23/2023, 7:10 PM

Hey Can someone guide me how to architect my base fragment to support to maintaining the view If user have came back from normal back press And if user done some action then comeback refresh the page and dont retain the view . Have anyone structured the same in baseFragment using databinding ??

galex

08/09/2023, 12:21 PM

Hello, I've got Fragment A (Start Destination) and then Fragment B which both use the same ViewModel, both using

saveStateHandle["id"]

to get an id from a deeplink. When coming back from Fragment B to Fragment A, The ViewModel of Fragment A also receives the same parameter

id

as the ViewModel of Fragment B receives it. Weird or what am I missing here?

Nacho Ruiz Martin

10/09/2023, 3:47 PM

Hey 👋 After updating some libraries, when invoking

onBackPressed

on our Activities, navigation component’s

popBackStack

is not called, only

finish

, even if the graph is not on its root. Is this expected? Should we override the default back behaviour with

OnBackPressedDispatcher

to manually call

popBackStack

and

finish

when the backstack is cleared out?