dioxus/packages/hooks/src/use_signal.rs
Jonathan Kelley 8cc17dc1bd
Fix compile
2024-01-29 17:03:50 -08:00

102 lines
3.2 KiB
Rust

use dioxus_core::prelude::*;
use dioxus_signals::{Signal, SignalData, Storage, SyncStorage, UnsyncStorage};
/// Creates a new Signal. Signals are a Copy state management solution with automatic dependency tracking.
///
/// ```rust
/// use dioxus::prelude::*;
/// use dioxus_signals::*;
///
/// fn App() -> Element {
/// let mut count = use_signal(|| 0);
///
/// // Because signals have automatic dependency tracking, if you never read them in a component, that component will not be re-rended when the signal is updated.
/// // The app component will never be rerendered in this example.
/// rsx! { Child { state: count } }
/// }
///
/// #[component]
/// fn Child(state: Signal<u32>) -> Element {
/// let state = *state;
///
/// use_future( |()| async move {
/// // Because the signal is a Copy type, we can use it in an async block without cloning it.
/// *state.write() += 1;
/// });
///
/// rsx! {
/// button {
/// onclick: move |_| *state.write() += 1,
/// "{state}"
/// }
/// }
/// }
/// ```
#[track_caller]
#[must_use]
pub fn use_signal<T: 'static>(f: impl FnOnce() -> T) -> Signal<T, UnsyncStorage> {
use_maybe_signal_sync(f)
}
/// Creates a new `Send + Sync`` Signal. Signals are a Copy state management solution with automatic dependency tracking.
///
/// ```rust
/// use dioxus::prelude::*;
/// use dioxus_signals::*;
///
/// fn App(cx: Scope) -> Element {
/// let mut count = use_signal_sync(cx, || 0);
///
/// // Because signals have automatic dependency tracking, if you never read them in a component, that component will not be re-rended when the signal is updated.
/// // The app component will never be rerendered in this example.
/// render! { Child { state: count } }
/// }
///
/// #[component]
/// fn Child(cx: Scope, state: Signal<u32, SyncStorage>) -> Element {
/// let state = *state;
///
/// use_future!(cx, |()| async move {
/// // This signal is Send + Sync, so we can use it in an another thread
/// tokio::spawn(async move {
/// // Because the signal is a Copy type, we can use it in an async block without cloning it.
/// *state.write() += 1;
/// }).await;
/// });
///
/// render! {
/// button {
/// onclick: move |_| *state.write() += 1,
/// "{state}"
/// }
/// }
/// }
/// ```
#[must_use]
#[track_caller]
pub fn use_signal_sync<T: Send + Sync + 'static>(f: impl FnOnce() -> T) -> Signal<T, SyncStorage> {
use_maybe_signal_sync(f)
}
#[must_use]
#[track_caller]
fn use_maybe_signal_sync<T: 'static, U: Storage<SignalData<T>>>(
f: impl FnOnce() -> T,
) -> Signal<T, U> {
#[cfg(debug_assertions)]
let caller = std::panic::Location::caller();
let signal = use_hook(|| {
Signal::new_with_caller(
f(),
#[cfg(debug_assertions)]
caller,
)
});
// By default, we want to unsubscribe the current component from the signal on every render
// any calls to .read() in the body will re-subscribe the component to the signal
use_before_render(move || signal.unsubscribe(current_scope_id().unwrap()));
signal
}