Nullability and LiveData with Kotlin

Question

I want to use LiveData with Kotlin and have values that should not be null. How do you deal with this? Perhaps a wrapper around LiveData? Searching for good patterns here .. As

Answer 1

I don't know if this is the best solution but this is what I came up with and what I use:

class NonNullLiveData(private val defaultValue: T) : MutableLiveData() {

    override fun getValue(): T = super.getValue() ?: defaultValue

    fun observe(owner: LifecycleOwner, body: (T) -> Unit) {
        observe(owner, Observer {
            body(it ?: defaultValue)
        })
    }
}

Creating the field:

val string = NonNullLiveData("")

And observing it:

viewModel.string.observe(this) {
    // Do someting with the data
}