Android hilt injection for SharedPreference

Question

I have been having issue with hilt injection as I am relatively new to the concept of DI, Here is the problem I have a class which manages my app session(Shared preference) and I want to inject that class to my use case(Activity/Fragment), now when I do this it throws this error

"lateinit property sessionManager has not been initialized"

code for SessionManager.kt

class SessionManager @Inject constructor(private val preferences: SharedPreferences) {

    fun getTheme() = preferences.getInt(Constants.THEME_KEY, AppCompatDelegate.MODE_NIGHT_NO)

    fun setTheme(value: Int) {
        val editor = preferences.edit()
        editor.putInt(Constants.THEME_KEY, value)
        editor.apply()
    }
}

code for appmoudle.kt

@Module
@InstallIn(SingletonComponent::class)
object AppModule {
@Singleton
    @Provides
    fun provideSharedPreferences(@ApplicationContext context: Context) =
        context.getSharedPreferences(
            Constants.PREF_NAME, Context.MODE_PRIVATE
        )

    @Singleton
    @Provides
    fun provideSessionManager(preferences: SharedPreferences) =
        SessionManager(preferences)
}

code for the activity I am injecting it in

@AndroidEntryPoint
class TrendingRepoActivity : BaseActivity(), View.OnClickListener {

    private lateinit var viewModel: TrendingRepoViewModel
    private lateinit var binding: ActivityTrendingReposBinding

    @Inject
    lateinit var sessionManager: SessionManager

    override fun onCreate(savedInstanceState: Bundle?) {
        AppCompatDelegate.setDefaultNightMode(sessionManager.getTheme())
        super.onCreate(savedInstanceState)
        binding = DataBindingUtil.setContentView(this, R.layout.activity_trending_repos)

        setSupportActionBar(binding.appBarLayout.toolbar)
        binding.errorView.retryBtn.setOnClickListener(this)

        init()
    }
}

user_7310758 · Answer

Ok so after digging this out it was not an hilt issue but a little blunder that I made

the issue was in the activity where I was calling the injected class before super.oncreate below is the fix

@AndroidEntryPoint
class TrendingRepoActivity : BaseActivity(), View.OnClickListener {
private lateinit var viewModel: TrendingRepoViewModel
private lateinit var binding: ActivityTrendingReposBinding

@Inject
lateinit var sessionManager: SessionManager

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    AppCompatDelegate.setDefaultNightMode(sessionManager.getTheme())
    binding = DataBindingUtil.setContentView(this, 
    R.layout.activity_trending_repos)

    setSupportActionBar(binding.appBarLayout.toolbar)
    binding.errorView.retryBtn.setOnClickListener(this)

        init()
    }
}

Android hilt injection for SharedPreference

1 Answers