PrevState

Description

The previous useActionState state, round-tripped from the client. None on the first render (or when the action is called imperatively without a prior state). A PrevState<T> parameter is how an action opts into React's (prevState, formData) => newState contract. The wrapped value is untrusted client input - never use it as authorization state.

Signature

pub struct PrevState<T>(Option<T>);

Examples

#[action]
async fn submit(prev: PrevState<FormState>, input: Subscribe) -> FormState {
    let attempts = prev.get().map(|s| s.attempts + 1).unwrap_or(1);
    FormState { attempts, ok: input.email.contains('@') }
}