Reduce boilerplate for view binding in fragments

1_FragmentViewBindingBoilerplate.kt

// Just for customizing the name

Aliases.kt

// This alias makes the code more readable
typealias BindingInflater<VB> = (inflater: LayoutInflater, container: ViewGroup?, attachToRoot: Boolean) -> VB

BaseFragment.kt

abstract class BaseFragment<VB : ViewBinding> : Fragment() {
  
  // This property must be nullable to prevent view leaks
  // Never forget that fragments outlive their views !
  private var mutableViewBinding: VB? = null

  // This property gives us a not nullable view binding for simpler use
  protected val viewBinding: VB get() = mutableViewBinding!!
  
  // This property is abstract because it has to be declared by the child class
  protected abstract val bindingInflater: BindingInflater<VB>

  override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
      mutableViewBinding = bindingInflater.invoke(inflater, container, false)
      return viewBinding.root
  }

  override fun onDestroyView() {
      super.onDestroyView()
      // Prevent view leaks
      mutableViewBinding = null
  }
}

build.gradle

android {
  ...
  
  // Enable view binding for module
  buildFeatures {
      viewBinding true
  }
  
  ...
}

ExampleFragment.kt

class ExampleFragment : BaseFragment<FragmentExampleBinding>() {
    
    // FragmentExampleBinding.inflate(...) matches the signature of BindingInflater so we can
    // set it as a BindingInflater for the FragmentExampleBinding class
    override val bindingInflater: BindingInflater<FragmentExampleBinding> = FragmentExampleBinding::inflate

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

        with(viewBinding) {
            // Set up your views
            ...
        }
    }
}