79 lines
2.1 KiB
Rust
79 lines
2.1 KiB
Rust
/// Creats a callback that will be run before the component is removed. This can be used to clean up side effects from the component (created with use_effect)
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///
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/// Example:
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/// ```rust
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/// use dioxus::prelude::*;
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/// fn main() {
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/// dioxus_web::launch(app)
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/// }
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/// fn app(cx: Scope) -> Element {
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/// let state = use_state(cx, || true);
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/// render! {
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/// for _ in 0..100 {
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/// h1 {
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/// "spacer"
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/// }
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/// }
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/// if **state {
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/// render! {
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/// child_component {}
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/// }
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/// }
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/// button {
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/// onclick: move |_| {
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/// state.set(!*state.get());
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/// },
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/// "Unmount element"
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/// }
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/// }
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/// }
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/// fn child_component(cx: Scope) -> Element {
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/// let original_scroll_position = use_state(cx, || 0.0);
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/// use_effect(cx, (), move |_| {
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/// to_owned![original_scroll_position];
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/// async move {
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/// let window = web_sys::window().unwrap();
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/// let document = window.document().unwrap();
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/// let element = document.get_element_by_id("my_element").unwrap();
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/// element.scroll_into_view();
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/// original_scroll_position.set(window.scroll_y().unwrap());
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/// }
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/// });
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/// use_on_unmount(cx, {
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/// to_owned![original_scroll_position];
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/// /// restore scroll to the top of the page
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/// move || {
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/// let window = web_sys::window().unwrap();
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/// window.scroll_with_x_and_y(*original_scroll_position.current(), 0.0);
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/// }
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/// });
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/// render!{
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/// div {
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/// id: "my_element",
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/// "hello"
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/// }
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/// }
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/// }
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/// ```
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pub fn use_on_unmount<C: FnOnce() + 'static, D: FnOnce() + 'static>(cx: &ScopeState, destroy: D) {
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cx.use_hook(|| LifeCycle {
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ondestroy: Some(destroy),
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});
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}
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struct LifeCycle<D: FnOnce()> {
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ondestroy: Option<D>,
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}
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impl<D: FnOnce()> Drop for LifeCycle<D> {
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fn drop(&mut self) {
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let f = self.ondestroy.take().unwrap();
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f();
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}
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}
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