// Register.kt

override fun onCreateView( inflater: LayoutInflater,
container: ViewGroup?, savedInstanceState: Bundle? ): View? {
    val binding: FragmentRegisterBinding = FragmentRegisterBinding.inflate(inflater, container, false)
    val registerViewModel = RegisterViewModel()
    binding.registerViewModel = registerViewModel
    binding.executePendingBindings()
    println("onCreate")
    val viewModel = ViewModelProviders.of(this).get(RegisterViewModel::class.java)
    viewModel.getErrors().observe(this, Observer {
        println("observed")
    })
    return binding.root
}

// RegisterViewModel.kt

    var email: MutableLiveData = MutableLiveData()
    var id: MutableLiveData = MutableLiveData()
    var name: MutableLiveData = MutableLiveData()
    var date: MutableLiveData = MutableLiveData()

    var errs: MutableLiveData> = MutableLiveData()

    fun getErrors(): MutableLiveData> {
        println("getErrors, livedata size: " + errs.value?.size)
        return errs
    }

    fun onRegisterClicked() {
        println("onButtonnClicked")
        var data = RegisterModel(id.value!!, email.value!!, name.value!!, date.value!!)
        var err: ArrayList = ArrayList()

        if (data.getEmail().length < 3) {
            err.add(Errors.ERREmail)
            println("errors size: " + err.size)
        }
        errs.value = err
    }