Module freya::_docs::state_management::memoization

Memoization

You can memoize values by using the use_memo hook. This can be useful to have reactive derived across components or to cache expensive value to compute.

fn app() -> Element {
    let mut state = use_signal(|| 1);
    // `use_memo` returns a `ReadOnlySignal`, as the name says it is a Signal
    // that you can read and subscribe to but you cannot mutate
    // as its value can only be changed when the memo runs
    let double_state = use_memo(move || {
        // Just like `use_effect`, whenever a signal that is read in here is changed, the memo will rerun.
        state() * 2
    });

    rsx!(
        label {
            onclick: move |_| state += 1,
            "{double_state}"
        }
    )
}