Function yewdux::functional::use_selector

pub fn use_selector<'hook, S, F, R>(
    selector: F
) -> impl 'hook + Hook<Output = Rc<R>>
where
    S: Store + 'hook,
    R: PartialEq + 'static + 'hook,
    F: Fn(&S) -> R + 'static + 'hook,

Provides access to some derived portion of state. Useful when you only want to rerender when that portion has changed.

Example

use yew::prelude::*;
use yewdux::prelude::*;

#[derive(Default, Clone, PartialEq, Store)]
struct State {
    count: u32,
}

#[function_component]
fn App() -> Html {
    let dispatch = use_dispatch::<State>();
    let count = use_selector(|state: &State| state.count);
    let onclick = dispatch.reduce_mut_callback(|state| state.count += 1);

    html! {
        <>
        <p>{ *count }</p>
        <button {onclick}>{"+1"}</button>
        </>
    }
}

Note

When used in function components and hooks, this hook is equivalent to:

pub fn use_selector<S, F, R>(selector: F) -> Rc<R>
where
    S: Store,
    R: PartialEq + 'static,
    F: Fn(&S) -> R + 'static,
{
    /* implementation omitted */
}