EpubReaderFragment.onCreate java.lang.IllegalStateException - Required value was null.

[mohab331]

I'm currently using version 2.2.1 of readium (https://github.com/readium/kotlin-toolkit/blob/2.2.1/test-app/src/main/java/org/readium/r2/testapp/reader/EpubReaderFragment.kt).
I've encountered an issue reported by Crashlytics. The error, a java.lang.IllegalStateException, specifically states: "Required value was null." The problem seems to be occurring in the reader.EpubReaderFragment.onCreate method at line 84.

Interestingly, this issue is not consistent across all devices. It occurs on some devices but not on others, even though they share the same model and Android version.

Has anyone else come across this particular issue, or does anyone have insights on how to resolve it? Any help would be greatly appreciated i have attached code snippets of where crashlytics has reported issue.

EpubReaderFragment.kt

[mickael-menu]

What's on line 84 of your EpubReaderFragment implementation?

Could you share the complete stacktrace from Crashlytics?

[mohab331]

@mickael-menu Sure here is full crashlitics but please note that this issue appear for about 10% of users not all users Also i have attached EpubReaderFragment onCreate():

Fatal Exception: java.lang.RuntimeException Unable to start activity ComponentInfo{customreader.reader.ReaderActivity}: java.lang.IllegalStateException: Required value was null.
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2793)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2864)
at android.app.ActivityThread.-wrap12(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1567)
at android.os.Handler.dispatchMessage(Handler.java:105)
at android.os.Looper.loop(Looper.java:156)
at android.app.ActivityThread.main(ActivityThread.java:6524)
at java.lang.reflect.Method.invoke(Method.java)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:941)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:831)

Caused by java.lang.IllegalStateException: Required value was null.
at customreader.reader.EpubReaderFragment.onCreate(EpubReaderFragment.kt:84)
at androidx.fragment.app.Fragment.performCreate(Fragment.java:2981)
at androidx.fragment.app.FragmentStateManager.create(FragmentStateManager.java:474)
at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:257)
at androidx.fragment.app.FragmentStore.moveToExpectedState(FragmentStore.java:113)
at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1374)
at androidx.fragment.app.FragmentManager.dispatchStateChange(FragmentManager.java:2841)
at androidx.fragment.app.FragmentManager.dispatchCreate(FragmentManager.java:2773)
at androidx.fragment.app.FragmentController.dispatchCreate(FragmentController.java:251)
at androidx.fragment.app.FragmentActivity.onCreate(FragmentActivity.java:252)
at customreader.reader.ReaderActivity.onCreate(ReaderActivity.kt:72)
at android.app.Activity.performCreate(Activity.java:6910)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1123)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2746)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2864)
at android.app.ActivityThread.-wrap12(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1567)
at android.os.Handler.dispatchMessage(Handler.java:105)
at android.os.Looper.loop(Looper.java:156)
at android.app.ActivityThread.main(ActivityThread.java:6524)
at java.lang.reflect.Method.invoke(Method.java)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:941)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:831)

[mohab331]

@mickael-menu and here is also ReaderActivity.kt lin 72 on Create()

[mickael-menu]

This happens because the process was killed and the reader activity restarted.

In this situation, a dummy VisualReaderInitData() without a baseUrl is created:

kotlin-toolkit/test-app/src/main/java/org/readium/r2/testapp/reader/ReaderViewModel.kt

Lines 248 to 252 in 7073077

	private fun dummyReaderInitData(bookId: Long): ReaderInitData {
	val metadata = Metadata(identifier = "dummy", localizedTitle = LocalizedString(""))
	val publication = Publication(Manifest(metadata = metadata))
	return VisualReaderInitData(bookId, publication)
	}

Which doesn't suit the EpubReaderFragment, as it requires a baseUrl. What you need to do is close the Reader activity in this case, as Readium doesn't yet support restoring the navigator from process death.

I recommend upgrading to Readium 2.4.0 as we added dummy navigator factories which help prevent crashes after process death: https://github.com/readium/kotlin-toolkit/blob/main/CHANGELOG.md#navigator

Note that the code you shared is part of the test app, which is just an example and is not updated with the Readium toolkit. If you copy samples from it, you need to take ownership of the code and maintain it.

I'm closing the issue as there's nothing to do in the toolkit.

[mohab331]

@mickael-menu is there any workaround that can be done without updating

[mickael-menu]

Not if you want to prevent all crashes, see: #395