BindingUtility.kt

@BindingAdapter("onTextChanged")
fun onTextChanged(inputText: InputText, block: (String) -> Unit) {
  inputText.addTextChangedListener(object : TextWatcher {
    override fun onTextChanged(CharSequence s, int start, int before, int count) {
      block(s.toString())
    }
  })
}

profile.xml

<layout>
  
  <variable name="interactor" type="com.theathletic.profile.presenter"/>
  
  ...
  
  <Input
    ...
    app:onTextChanged="@{(text) -> interactor.onEmailChanged(text)}"
    />
  
</layout>

ProfilePresenter.kt

interface ProfileInterator {
  fun onEmailChange(emailText: String)
}

class ProfilePresenter(...) : ProfileInteractor {
  
  ...
  
  override fun onEmailChanged(emailText: String) {
    updateState {
      copy(email = emailText)
    }
  }

}