class CategoryEntry(title: String, url: String, val types: String)  : Entry(title, url) {
    override fun toString(): String {
        return super.toString()+"- $types"
    }
}

class CategoryEntryModel(val categoryentry: CategoryEntry) : ViewModel() {
    val types = bind { SimpleStringProperty(categoryentry.types) }
}

onUserSelect {
            controller.categoryEntryModel.rebind {
                categoryentry = selectedItem ?: CategoryEntry("", "", 0)
            }

        }

ItemViewModel

categoryEntryModel.onchange {
    runAsync {
       // something to run
    } ui {
       items = it
   }
}

asyncItems { something to run that returns items  }

asyncItems

runAsync