Using fragmentFactory with Navigation Component

Describe the bug App crashes when I try to inject dependencies via the fragment constructor with Koin fragmentFactory and JetPack navigation component.

To Reproduce

1. Use JetPack navigation component to create a “single-activity” app.
2. Create a fragment inside the navigation graph.
3. Inject any dependency into the fragment’s constructor with Koin fragmentFactory.
4. App crashes when the navigation component tries to inflate the fragment. The following is the error log.

2020-01-08 15:02:30.459 27978-27978/com.example.koinfragmentfactoryissue E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.koinfragmentfactoryissue, PID: 27978
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.koinfragmentfactoryissue/com.example.koinfragmentfactoryissue.BaseActivity}: android.view.InflateException: Binary XML file line #22: Binary XML file line #22: Error inflating class fragment
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2781)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2859)
        at android.app.ActivityThread.-wrap11(Unknown Source:0)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1592)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loop(Looper.java:164)
        at android.app.ActivityThread.main(ActivityThread.java:6518)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
     Caused by: android.view.InflateException: Binary XML file line #22: Binary XML file line #22: Error inflating class fragment
     Caused by: android.view.InflateException: Binary XML file line #22: Error inflating class fragment
     Caused by: org.koin.core.error.NoBeanDefFoundException: No definition found for class:'androidx.navigation.fragment.NavHostFragment'. Check your definitions!
        at org.koin.core.scope.Scope.throwDefinitionNotFound(Scope.kt:245)
        at org.koin.core.scope.Scope.resolveInstance(Scope.kt:219)
        at org.koin.core.scope.Scope.get(Scope.kt:176)
        at org.koin.core.Koin.get(Koin.kt:113)
        at org.koin.core.Koin.get$default(Koin.kt:112)
        at org.koin.androidx.fragment.android.KoinFragmentFactory.instantiate(KoinFragmentFactory.kt:16)
        at androidx.fragment.app.FragmentLayoutInflaterFactory.onCreateView(FragmentLayoutInflaterFactory.java:97)
        at androidx.fragment.app.FragmentController.onCreateView(FragmentController.java:135)
        at androidx.fragment.app.FragmentActivity.dispatchFragmentsOnCreateView(FragmentActivity.java:356)
        at androidx.fragment.app.FragmentActivity.onCreateView(FragmentActivity.java:335)
        at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:780)
        at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:730)
        at android.view.LayoutInflater.rInflate(LayoutInflater.java:863)
        at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:824)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:515)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:423)
        at android.view.LayoutInflater.inflate(LayoutInflater.java:374)
        at androidx.appcompat.app.AppCompatDelegateImpl.setContentView(AppCompatDelegateImpl.java:555)
        at androidx.appcompat.app.AppCompatActivity.setContentView(AppCompatActivity.java:161)
        at com.example.koinfragmentfactoryissue.BaseActivity.onCreate(BaseActivity.kt:16)
        at android.app.Activity.performCreate(Activity.java:7023)
        at android.app.Activity.performCreate(Activity.java:7014)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1215)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2734)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2859)
        at android.app.ActivityThread.-wrap11(Unknown Source:0)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1592)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loop(Looper.java:164)
        at android.app.ActivityThread.main(ActivityThread.java:6518)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)

The following are some example codes.

// BaseApplication.kt
class BaseApplication : Application() {
    val appModule = module {
        single { MyApi() }
        fragment { MainFragment(get()) }
    }
    override fun onCreate() {
        super.onCreate()
        startKoin {
            androidLogger()
            androidContext(this@BaseApplication)
            fragmentFactory()
            modules(appModule)
        }
    }
}

// BaseActivity.kt
class BaseActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setupKoinFragmentFactory()
        setContentView(R.layout.activity_base)
        setSupportActionBar(toolbar)
        val navController = findNavController(R.id.nav_host_fragment)
        val appBarConfiguration = AppBarConfiguration(navController.graph)
        toolbar.setupWithNavController(navController, appBarConfiguration)
    }
}

// MainFragment.kt
class MainFragment(private val myApi: MyApi) : Fragment() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        myApi.hello()
    }
    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        return inflater.inflate(R.layout.fragment_main, container, false)
    }
}

// MyApi.kt
private const val TAG = "MyApi"
class MyApi {
    fun hello() {
        Log.i(TAG, "hello")
    }
}

Expected behavior The fragment should be successfully inflated with MyApi injected.

Koin project used and used version (please complete the following information): org.koin:koin-android:2.1.0-alpha-10 org.koin:koin-androidx-fragment:2.1.0-alpha-10

[seanwu1105]

@abjorck Yes, the building process is successful by adding fragment { NavHostFragment() } to the appModule. However, I am not sure how to get the instance of a specific navigation graph if an app contains multiple NavHostFragments.

@nikhil-thakkar After adding fragment { NavHostFragment() } to the appModule, the app works fine no matter the order of setupKoinFragmentFactory() and super.onCreate(saveInstance) on my testing devices.

[nikhil-thakkar]

@seanwu1105 Could you try calling setupKoinFragmentFactory() before super.onCreate(saveInstance)? And the same holds true if you don’t use Koin. You have to set the FragmentFactory to SupportFragmentManager before calling super.onCreate(saveInstance).