yew_hooks/hooks/
use_interval.rs

1use gloo::timers::callback::Interval;
2use yew::prelude::*;
3
4use super::use_mut_latest;
5
6/// A hook that schedules an interval to invoke `callback` every `millis` milliseconds.
7/// The interval will be cancelled if `millis` is set to 0.
8///
9/// # Example
10///
11/// ```rust
12/// # use yew::prelude::*;
13/// #
14/// use yew_hooks::prelude::*;
15///
16/// #[function_component(Interval)]
17/// fn interval() -> Html {
18///     let state = use_state(|| 0);
19///
20///     {
21///         let state = state.clone();
22///         use_interval(move || {
23///             state.set(*state + 1);
24///         }, 2000);
25///     }
26///     
27///     html! {
28///         <>
29///             { *state }
30///         </>
31///     }
32/// }
33/// ```
34#[hook]
35pub fn use_interval<Callback>(callback: Callback, millis: u32)
36where
37    Callback: FnMut() + 'static,
38{
39    let callback_ref = use_mut_latest(callback);
40    let interval_ref = use_mut_ref(|| None);
41
42    use_effect_with(millis, move |millis| {
43        if *millis > 0 {
44            *interval_ref.borrow_mut() = Some(Interval::new(*millis, move || {
45                let callback_ref = callback_ref.current();
46                let callback = &mut *callback_ref.borrow_mut();
47                callback();
48            }));
49        } else {
50            *interval_ref.borrow_mut() = None;
51        }
52
53        move || *interval_ref.borrow_mut() = None
54    });
55}
yew_hooks/hooks/use_interval.rs

yew_hooks/hooks/
use_interval.rs
