Android Kotlin with Dagger2, lateinit var has not been initialized

Question

I'm a Dagger newb and have a trouble with using it.

What I want to develop is that using RxAndroidBle and to initialize it by Dagger for providing Context.

So I researched how it can be implemented, and I wrote some codes and It seems to be working for me but not working at all.

The followings are my codes.

AppComponent.kt

@Singleton
@Component(modules = [
    AppModule::class,
    BluetoothModule::class,
    AndroidInjectionModule::class])
interface AppComponent : AndroidInjector<BluetoothController> {

    @Component.Builder
    interface Builder {

        @BindsInstance
        fun application(app: Application): Builder

        fun build(): AppComponent
    }
}

AppModule.kt

@Module
class AppModule {

    @Provides
    @Named("appContext")
    @Singleton
    fun provideContext(application: Application): Context =
            application.applicationContext
}

BluetoothModule.kt

@Module
class BluetoothModule {

    @Provides
    @Named("rxBleClient")
    @Singleton
    fun provideRxBleClient(@Named("appContext") context: Context):RxBleClient =
            RxBleClient.create(context)
}

BluetoothController.kt for injecting by DaggerApplication.

class BluetoothController : DaggerApplication() {

    override fun applicationInjector(): AndroidInjector<out DaggerApplication> {
        return DaggerAppComponent.builder().application(this).build()
    }
}

I've inserted android:name".BluetoothController" to AndroidManifest.xml

And this is how I would use it.

@field:[Inject Named("rxBleClient")]
lateinit var rxBleClient: RxBleClient

But it always occurs an error says: lateinit property context has not been initialized

What things I've missed? Can anyone help me?

Thanks in advance.

score 2 · Accepted Answer · answered Aug 09 '18 at 06:14

Add the below code to make this happen.

Create ActivityBuilderModule for injecting within the activity. Consider our activity as MainActivity

@Module
abstract class ActivityBuilderModule {
     @ContributesAndroidInjector(modules=[MainActivityModule::class])
     abstract fun contributeSplashActivity(): MainActivity
}

Create your MainActivityModule

@Module
class MainActivityModule{
     @Provides()
     fun contributeSplashActivity(mainActivity: MainActivity): 
        MainActivity=mainActivity
 }

Modify your component.

@Singleton
@Component(modules = [
AppModule::class,
BluetoothModule::class,
ActivityBuilderModule::class,
AndroidInjectionModule::class])
interface AppComponent : AndroidInjector<BluetoothController> {

    @Component.Builder
    interface Builder {

        @BindsInstance
        fun application(app: Application): Builder

        fun build(): AppComponent
    }
}

Within MainActivity just inject.

class MainActivity{
      ...
      @Inject
      lateinit var rxBleClient: RxBleClient
      override fun onCreate(savedInstanceState: Bundle?) {

        AndroidInjection.inject(this)
        super.onCreate(savedInstanceState)
      }
}

Let us know in case of any issue.

I've already solved my issue as the way like you suggested :) Thanks! This is the cause I had missed. — Awesometic, Aug 10 '18 at 02:00

Declan Nnadozie · Answer 2 · 2018-08-08T13:55:13.513

0

the context object is not initialized before its called

Though i dont know, how chained your initialization are.

Use @Inject to add deppendencies, do something like this

    @Module
class BluetoothModule(val context : Context) {

    //@Inject private lateinit var context : Context
    @Provides
    @Named("rxBleClient")
    @Singleton
    fun provideRxBleClient():RxBleClient =
            RxBleClient.create(context)
}

let your call be like this

val component = AppComponent()
 component.bluetoothModule(appContext)
          .//other calls here
          .build()

edited Aug 08 '18 at 13:55

answered Aug 08 '18 at 09:53

Declan Nnadozie

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I tried that put the injection code for Context separately but it doesn't work.. Thank you for your reply! – Awesometic Aug 08 '18 at 13:35
trying adding the context via Bluetooth constructor..... the above code @Awesometic – Declan Nnadozie Aug 08 '18 at 13:55
It seems the suggested answer doesn't use of the dagger.android features.. AppComponent is already defined with the class extends DaggerApplication class. And I found that it isn't needed to inject between module classes. Is it right? I'm a newb so I searched as much as I can. :) But anyway your answer inspires me in some way and I could get the answer. Thanks. – Awesometic Aug 09 '18 at 04:36

Android Kotlin with Dagger2, lateinit var has not been initialized

2 Answers2