@Inject for Hilt is giving UninitializedPropertyAccessException-CodePudding

I am using Hilt in my project, and it is working fine everywhere apart from this one file.

abstract class SomeFile {
  
    @Inject
    lateinit var useCase: UseCase

    fun setData() {
       if (useCase.driver == 1){ do something }
       else { do something }
    }
}

This same "UseCase" inject is working in another files like viewmodel and activity. But only in this abstract class file is where I am getting this exception. What could be the issue here?

Module class

@Module
@InstallIn(SingletonComponent::class)
object HiltUseModule {
    @Provides
    @Singleton
    fun getUseCase(stateMachine: StateMachine): UseCase {
        return createProxyInstance(stateMachine)
    }
}

The app doesn't crash or anything. It just goes to the if condition and doesn't do anything. I used debug to check what is the value of 'useCase' there, and it shows the exception UninitializedPropertyAccessException.

Thanks in advance.

CodePudding user response：

Try this :

abstract class SomeFile {
 
    fun setData(useCase : UseCase) {
       if (useCase.driver == 1){ do something }
       else { do something }
    }
}

What it does is that the parameter that you pass in function will find object of UseCase from wherever it can.

CodePudding user response：

Rather than field injection, you should use constructor injection to acquire an instance of SomeFile.

class SomeFile @Inject internal constructor(private val useCase: UseCase) {
  fun setData() {
    if (useCase.driver == 1){ do something }
      else { do something }
    }
  }
}

Then, you will need to inject this into some component which is an entry point (whether that's your ViewModel, Fragment, or Activity:

@AndroidEntryPoint(AppCompatActivity::class)
class MyActivity : Hilt_AppCompatActivity() {
  @Inject internal lateinit var someFile: SomeFile

  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    someFile.setData()
  }
}