46 lines
1.4 KiB
Rust
46 lines
1.4 KiB
Rust
use crate::use_callback;
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use dioxus_core::prelude::*;
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use dioxus_signals::{Memo, Signal};
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/// Creates a new Memo. The memo will be run immediately and whenever any signal it reads changes.
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///
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/// Memos can be used to efficiently compute derived data from signals.
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///
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/// ```rust
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/// use dioxus::prelude::*;
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/// use dioxus_signals::*;
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///
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/// fn App() -> Element {
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/// let mut count = use_signal(|| 0);
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/// let double = use_memo(move || count * 2);
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/// count += 1;
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/// assert_eq!(double(), count * 2);
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///
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/// rsx! { "{double}" }
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/// }
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/// ```
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///
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/// ## With non-reactive dependencies
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/// To add non-reactive dependencies, you can use the `use_reactive` hook.
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///
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/// Signals will automatically be added as dependencies, so you don't need to call this method for them.
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///
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/// ```rust
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/// # use dioxus::prelude::*;
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/// # async fn sleep(delay: u32) {}
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///
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/// #[component]
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/// fn Comp(count: u32) -> Element {
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/// // Because the memo subscribes to `count` by adding it as a dependency, the memo will rerun every time `count` changes.
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/// let new_count = use_memo(use_reactive((&count,), |(count,)| count + 1));
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///
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/// todo!()
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/// }
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/// ```
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#[track_caller]
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pub fn use_memo<R: PartialEq>(f: impl FnMut() -> R + 'static) -> Memo<R> {
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let callback = use_callback(f);
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#[allow(clippy::redundant_closure)]
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use_hook(|| Signal::memo(move || callback()))
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}
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