I have 2 users in firestore:
The app crashes when I click on the PEOPLE tab.
I’m getting this error in logcat:
java.lang.RuntimeException: Failed to call observer method
java.lang.RuntimeException: Failed to call observer method
@Apoorv4123 I’m unable to login myself, can you check what particular code gives the error in related to observer, also share the logcat when there is a crash
2021-06-05 22:43:43.639 20142-20142/com.example.whatsappclone E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.whatsappclone, PID: 20142
java.lang.RuntimeException: Failed to call observer method
** at** androidx.lifecycle.ClassesInfoCache$MethodReference.invokeCallback(ClassesInfoCache.java:226)
at androidx.lifecycle.ClassesInfoCache$CallbackInfo.invokeMethodsForEvent(ClassesInfoCache.java:194)
at androidx.lifecycle.ClassesInfoCache$CallbackInfo.invokeCallbacks(ClassesInfoCache.java:185)
at androidx.lifecycle.ReflectiveGenericLifecycleObserver.onStateChanged(ReflectiveGenericLifecycleObserver.java:37)
at androidx.lifecycle.LifecycleRegistry$ObserverWithState.dispatchEvent(LifecycleRegistry.java:354)
at androidx.lifecycle.LifecycleRegistry.forwardPass(LifecycleRegistry.java:265)
at androidx.lifecycle.LifecycleRegistry.sync(LifecycleRegistry.java:307)
at androidx.lifecycle.LifecycleRegistry.moveToState(LifecycleRegistry.java:148)
at androidx.lifecycle.LifecycleRegistry.handleLifecycleEvent(LifecycleRegistry.java:134)
at androidx.fragment.app.FragmentViewLifecycleOwner.handleLifecycleEvent(FragmentViewLifecycleOwner.java:88)
at androidx.fragment.app.Fragment.performStart(Fragment.java:3028)
at androidx.fragment.app.FragmentStateManager.start(FragmentStateManager.java:589)
at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:300)
at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:2189)
at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:2100)
at androidx.fragment.app.FragmentManager.execSingleAction(FragmentManager.java:1971)
at androidx.fragment.app.BackStackRecord.commitNow(BackStackRecord.java:305)
at androidx.viewpager2.adapter.FragmentStateAdapter.placeFragmentInViewHolder(FragmentStateAdapter.java:341)
at androidx.viewpager2.adapter.FragmentStateAdapter.onViewAttachedToWindow(FragmentStateAdapter.java:276)
at androidx.viewpager2.adapter.FragmentStateAdapter.onViewAttachedToWindow(FragmentStateAdapter.java:67)
at androidx.recyclerview.widget.RecyclerView.dispatchChildAttached(RecyclerView.java:7867)
at androidx.recyclerview.widget.RecyclerView$5.addView(RecyclerView.java:893)
at androidx.recyclerview.widget.ChildHelper.addView(ChildHelper.java:107)
at androidx.recyclerview.widget.RecyclerView$LayoutManager.addViewInt(RecyclerView.java:8902)
at androidx.recyclerview.widget.RecyclerView$LayoutManager.addView(RecyclerView.java:8860)
at androidx.recyclerview.widget.RecyclerView$LayoutManager.addView(RecyclerView.java:8848)
at androidx.recyclerview.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1645)
at androidx.recyclerview.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1591)
at androidx.recyclerview.widget.LinearLayoutManager.scrollBy(LinearLayoutManager.java:1395)
at androidx.recyclerview.widget.LinearLayoutManager.scrollHorizontallyBy(LinearLayoutManager.java:1124)
at androidx.recyclerview.widget.RecyclerView.scrollStep(RecyclerView.java:1969)
at androidx.recyclerview.widget.RecyclerView$SmoothScroller.onAnimation(RecyclerView.java:12316)
at androidx.recyclerview.widget.RecyclerView$ViewFlinger.run(RecyclerView.java:5564)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:970)
at android.view.Choreographer.doCallbacks(Choreographer.java:782)
at android.view.Choreographer.doFrame(Choreographer.java:714)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:956)
at android.os.Handler.handleCallback(Handler.java:790)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:200)
at android.app.ActivityThread.main(ActivityThread.java:6956)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:519)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:836)
2021-06-05 22:43:43.642 20142-20142/com.example.whatsappclone E/AndroidRuntime: Caused by: java.lang.IllegalStateException: Attempt to access dataSource on a PagedList that was instantiated with a InitialPagingSource instead of a DataSource
at androidx.paging.PagedList.getDataSource(PagedList.kt:984)
at com.firebase.ui.firestore.paging.FirestorePagingAdapter$5.apply(FirestorePagingAdapter.java:98)
at com.firebase.ui.firestore.paging.FirestorePagingAdapter$5.apply(FirestorePagingAdapter.java:95)
at androidx.lifecycle.Transformations$2.onChanged(Transformations.java:143)
at androidx.lifecycle.MediatorLiveData$Source.onChanged(MediatorLiveData.java:152)
at androidx.lifecycle.LiveData.considerNotify(LiveData.java:133)
at androidx.lifecycle.LiveData.dispatchingValue(LiveData.java:146)
at androidx.lifecycle.LiveData$ObserverWrapper.activeStateChanged(LiveData.java:468)
at androidx.lifecycle.LiveData.observeForever(LiveData.java:234)
at androidx.lifecycle.MediatorLiveData$Source.plug(MediatorLiveData.java:141)
at androidx.lifecycle.MediatorLiveData.onActive(MediatorLiveData.java:118)
at androidx.lifecycle.LiveData.changeActiveCounter(LiveData.java:390)
at androidx.lifecycle.LiveData$ObserverWrapper.activeStateChanged(LiveData.java:466)
at androidx.lifecycle.LiveData.observeForever(LiveData.java:234)
at com.firebase.ui.firestore.paging.FirestorePagingAdapter.startListening(FirestorePagingAdapter.java:181)
at java.lang.reflect.Method.invoke(Native Method)
at androidx.lifecycle.ClassesInfoCache$MethodReference.invokeCallback(ClassesInfoCache.java:216)
… 43 more
In the course the library used is paging2 and in your app the library used is paging 3
It works if you use paging2 instead i.e, 2.1.2 version
https://developer.android.com/topic/libraries/architecture/paging
There are some changes in the paging 3 you can look into paging3 migration if interested
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