VanX.reactive oldVal?

[HEAVYPOLY]

Hi, I'm not sure if I'm making a mistake here, how do you access oldVal with vanX.reactive?
const st = vanX.reactive({
page: 'paint',
params: 'abs',
})

text += page: ${st.page} |
text += prevpage: ${st.page.oldVal} |

st.page.oldVal always returns undefined

also tried st.oldVal.page

[Tao-VanJS]

You can use vanX.stateFields to access the underlying fields.

[HEAVYPOLY]

perfect, thank you