Base-Fragment with Hilt

An example of the beautiful Base-Fragment. {ViewBinding, ViewModel, Hilt}

BASE_FRAGMENT {ViewBinding, ViewModel, Hilt}

BF — Base: Fragment.

This is my personal vision, BF and I believe that in BF there should be only ViewBinding and ViewModel, and in this article I will show you how to perfectly implement this with the help of {reflection, ViewBinding, fragment:ktx }.

1️⃣ ViewBinding

path: build.gradle/android { … }

buildFeatures {
    viewBinding = true
}

2️⃣ Fragment KTX

path: build.gradle/dependencies{ … }

implementation "androidx.fragment:fragment-ktx:version" // 1.3.4

Required for convenient implementation ViewModel.

3️⃣ BF

abstract class BaseFragment<VB : ViewBinding, VM : ViewModel> : Fragment() {

    protected lateinit var binding: VB private set
    protected lateinit var viewModel: VM private set

    private val type = (javaClass.genericSuperclass as ParameterizedType)
    private val classVB = type.actualTypeArguments[0] as Class<VB>
    private val classVM = type.actualTypeArguments[1] as Class<VM>

    private val inflateMethod = classVB.getMethod(
        "inflate",
        LayoutInflater::class.java,
        ViewGroup::class.java,
        Boolean::class.java
    )

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {

        binding = inflateMethod.invoke(null, inflater, container, false) as VB
        viewModel = createViewModelLazy(classVM.kotlin, { viewModelStore }).value

        return binding.root
    }
}

4️⃣ Use

@AndroidEntryPoint
class UseFragment : BaseFragment<FragmentUseBinding, UseViewModel>() {

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

        binding.root
        viewModel.textMethod()
    }

5️⃣ Applause and joy because now you know more, and by the way, read a very useful thing about reflection 😉.

PS. Vel_daN: Love what You DO 💚