I am facing one issue using dagger2 + Kotlin This...

# android

[paras]

I am facing one issue using dagger2 + Kotlin

This is my ModuleClass

object AppModule {

    @JvmStatic
    @Provides
    fun provideRequestOptions() = RequestOptions.placeholderOf(R.drawable.white_background)
            .error(R.drawable.white_background)

    @JvmStatic
    @Provides
    fun provideGlideInstance(application: Application, requestOptions: RequestOptions) =
            Glide.with(application).setDefaultRequestOptions(requestOptions)

    @JvmStatic
    @Provides
    fun provideAppDrawable(application: Application) =
            ContextCompat.getDrawable(application, R.drawable.logo)
}

In my Activity I am using 2 injects

@Inject
    lateinit var drawableLogo: Drawable

    @Inject
    lateinit var requestManager: RequestManager

    fun setLogo() = requestManager.load(drawableLogo).into(loginLogo)

I am getting below error:-

/app/build/tmp/kapt3/stubs/debug/com/example/di/AppComponent.java:7: error: [Dagger/Nullable] android.graphics.drawable.Drawable is not nullable, but is being provided by @org.jetbrains.annotations.Nullable @Provides android.graphics.drawable.Drawable com.example.di.AppModule.provideAppDrawable(android.app.Application)
public abstract interface AppComponent extends dagger.android.AndroidInjector<com.example.BaseApplication> {
                ^
      android.graphics.drawable.Drawable is injected at
          com.example.AuthActivity.drawableLogo
      com.example.AuthActivity is injected at
          dagger.android.AndroidInjector.inject(T) [com.example.di.AppComponent → com.example.di.ActivityBuildersModule_ContributeAuthActivity$app_debug.AuthActivitySubcomponent]

FAILURE: Build failed with an exception.

I think this issue is somehow related to @Nullable annotation used by the IDE but I am not sure about the exact issue, can somebody explain about this issue?

[dawidhyzy]

>>

⚠️ Using Kotlin to build Android applications. google can answer many questions.
Android Studio Integration.
Android-specific Gradle.
If not related to Kotlin, please consider using StackOverflow and/or http://android-united.community/.

[Melih Aksoy]

You’re providing a drawable which is nullable ( ContextCompat.getDrawable returns Drawable? type ) but expecting a non-nullable injection in your field. Try to use non-nullable return type in module or mark your drawableLogo as nullable.

[kingsley]

Tip:
Always explicitly specify the return type of provides methods. Saves you a lot of unnecessary stress 😄

[paras]

thx @Melih Aksoy, apparently I ran into another problem after changing Drawble to Drawable?, as lateinit can’t be used with nullable types.

@Inject
lateinit var drawableLogo: Drawable? = null

then I needed to change lateinit to something like internal but then it gave another error “Dagger doesn’t support injection into private fields.

then finally I used something like

@set:Inject
internal var drawableLogo: Drawable? = null

but I don’t understand how this is working 😐