feat: use future fully figured out

This commit is contained in:
Jonathan Kelley 2022-02-21 15:39:47 -05:00
parent 86729d929d
commit 9211e1fc78
7 changed files with 481 additions and 348 deletions

View file

@ -16,7 +16,9 @@ struct ListBreeds {
}
fn app(cx: Scope) -> Element {
let breeds = use_future(&cx, || async move {
let (breed, set_breed) = use_state(&cx, || None);
let breeds = use_future(&cx, (), |_| async move {
reqwest::get("https://dog.ceo/api/breeds/list/all")
.await
.unwrap()
@ -24,13 +26,10 @@ fn app(cx: Scope) -> Element {
.await
});
let (breed, set_breed) = use_state(&cx, || None);
match breeds.value() {
Some(Ok(breeds)) => cx.render(rsx! {
div {
h1 {"Select a dog breed!"}
h1 { "Select a dog breed!" }
div { display: "flex",
ul { flex: "50%",
breeds.message.keys().map(|breed| rsx!(
@ -51,34 +50,23 @@ fn app(cx: Scope) -> Element {
}
}
}),
Some(Err(_e)) => cx.render(rsx! {
div { "Error fetching breeds" }
}),
None => cx.render(rsx! {
div { "Loading dogs..." }
}),
Some(Err(_e)) => cx.render(rsx! { div { "Error fetching breeds" } }),
None => cx.render(rsx! { div { "Loading dogs..." } }),
}
}
#[derive(serde::Deserialize, Debug)]
struct DogApi {
message: String,
}
#[inline_props]
fn Breed(cx: Scope, breed: String) -> Element {
#[derive(serde::Deserialize, Debug)]
struct DogApi {
message: String,
}
let endpoint = format!("https://dog.ceo/api/breed/{}/images/random", breed);
let fut = use_future(&cx, || async move {
let fut = use_future(&cx, (breed,), |(breed,)| async move {
let endpoint = format!("https://dog.ceo/api/breed/{}/images/random", breed);
reqwest::get(endpoint).await.unwrap().json::<DogApi>().await
});
let (name, set_name) = use_state(&cx, || breed.clone());
if name != breed {
set_name(breed.clone());
fut.restart();
}
cx.render(match fut.value() {
Some(Ok(resp)) => rsx! {
button {

View file

@ -52,7 +52,7 @@ fn app(cx: Scope) -> Element {
/// Suspense is achieved my moving the future into only the component that
/// actually renders the data.
fn Doggo(cx: Scope) -> Element {
let fut = use_future(&cx, || async move {
let fut = use_future(&cx, (), |_| async move {
reqwest::get("https://dog.ceo/api/breeds/image/random/")
.await
.unwrap()

View file

@ -12,8 +12,8 @@ fn main() {
fn app(cx: Scope) -> Element {
let (count, set_count) = use_state(&cx, || 0);
use_future(&cx, move || {
let set_count = set_count.to_owned();
use_future(&cx, (), move |_| {
let set_count = set_count.clone();
async move {
loop {
tokio::time::sleep(Duration::from_millis(1000)).await;

View file

@ -748,7 +748,7 @@ impl ScopeState {
}
// todo: attach some state to the future to know if we should poll it
pub fn remove_future(&self, id: TaskId) {
pub fn cancel_future(&self, id: TaskId) {
self.tasks.remove_fut(id);
}

182
packages/hooks/docs/old.md Normal file
View file

@ -0,0 +1,182 @@
mod use2 {
#![allow(missing_docs)]
use dioxus_core::{ScopeState, TaskId};
use std::{
any::Any,
cell::{Cell, RefCell},
future::Future,
rc::Rc,
};
/// A future that resolves to a value.
///
/// This runs the future only once - though the future may be regenerated
/// through the [`UseFuture::restart`] method.
///
/// This is commonly used for components that cannot be rendered until some
/// asynchronous operation has completed.
///
///
///
///
///
pub fn use_future<'a>(
// pub fn use_future<'a, T: 'static, F: Future<Output = T> + 'static>(
cx: &'a ScopeState,
) -> &'a UseFuture<()> {
// let state = cx.use_hook(move |_| UseFuture {
// update: cx.schedule_update(),
// needs_regen: Cell::new(true),
// slot: Rc::new(Cell::new(None)),
// value: None,
// task: None,
// pending: true,
// dep_cont: Cell::new(0),
// deps: RefCell::new(Vec::new()),
// first_time: true,
// });
// if let Some(value) = state.slot.take() {
// state.value = Some(value);
// state.task = None;
// }
// if state.needs_regen.get() {
// // We don't need regen anymore
// state.needs_regen.set(false);
// state.pending = false;
// // Create the new future
// let fut = new_fut();
// // Clone in our cells
// let slot = state.slot.clone();
// let updater = state.update.clone();
// state.task = Some(cx.push_future(async move {
// let res = fut.await;
// slot.set(Some(res));
// updater();
// }));
// }
// state.first_time = false;
// state
// new_fut: impl FnOnce() -> F,
todo!()
}
pub enum FutureState<'a, T> {
Pending,
Complete(&'a T),
Regenerating(&'a T), // the old value
}
pub struct UseFuture<T> {
update: Rc<dyn Fn()>,
needs_regen: Cell<bool>,
value: Option<T>,
slot: Rc<Cell<Option<T>>>,
task: Option<TaskId>,
pending: bool,
deps: RefCell<Vec<Box<dyn Any>>>,
dep_cont: Cell<usize>,
first_time: bool,
}
impl<T> UseFuture<T> {
pub fn restart(&self) {
self.needs_regen.set(true);
(self.update)();
}
// clears the value in the future slot without starting the future over
pub fn clear(&self) -> Option<T> {
(self.update)();
self.slot.replace(None)
}
// Manually set the value in the future slot without starting the future over
pub fn set(&self, new_value: T) {
self.slot.set(Some(new_value));
self.needs_regen.set(true);
(self.update)();
}
pub fn value(&self) -> Option<&T> {
self.value.as_ref()
}
pub fn state(&self) -> FutureState<T> {
// self.value.as_ref()
FutureState::Pending
}
pub fn build<F>(&self, new_fut: impl FnOnce() -> F) {}
}
#[test]
fn test_use_future_deps() {
use dioxus_core::prelude::*;
struct MyProps {
val: String,
name: i32,
}
fn app(cx: Scope<MyProps>) -> Element {
let MyProps { val, name } = cx.props;
// let val = use_c(&cx)
// .use_dep(val)
// .restart_if(|| false)
// .use_dep(name)
// .build(|(val, name)| async move {});
// async fn fetch_thing(name: String, num: i32) -> String {
// format!("{} {}", name, num)
// }
// let val = use_future(&cx, || fetch_thing(val.clone(), *name))
// .with_dep(val)
// .with_dep(name)
// .restart_if(|| false);
None
}
}
// pub struct CoroutineBuilder<'a, const PARAM: usize> {
// deps: Vec<Box<dyn Any>>,
// cx: &'a ScopeState,
// }
// macro_rules! dep_impl {
// ($id1:literal to $id2:literal) => {
// impl<'a> CoroutineBuilder<'a, $id1> {
// pub fn use_dep<F: 'static + PartialEq + Clone>(
// mut self,
// dep: &F,
// ) -> CoroutineBuilder<'a, $id2> {
// self.deps.push(Box::new(dep.clone()));
// unsafe { std::mem::transmute(self) }
// }
// }
// };
// }
// dep_impl!(0 to 1);
// dep_impl!(1 to 2);
// dep_impl!(2 to 3);
// dep_impl!(3 to 4);
// dep_impl!(4 to 5);
// dep_impl!(5 to 6);
// dep_impl!(6 to 7);
// dep_impl!(7 to 8);
// dep_impl!(8 to 9);
}

View file

@ -9,95 +9,82 @@ use std::{cell::Cell, rc::Rc};
/// Maintain a handle over a future that can be paused, resumed, and canceled.
///
/// This is an upgraded form of use_future with lots of bells-and-whistles.
/// This is an upgraded form of [`use_future`] with lots of bells-and-whistles.
///
/// [`use_coroutine`] is well suited for long-running tasks and is very customizable.
///
///
/// ## Long running tasks
///
///
///
/// ## One-off tasks
///
///
/// ## Cancellation
///
///
///
///
///
///
///
///
///
///
///
pub fn use_coroutine<'a, O: 'static, M: 'static>(
cx: &'a ScopeState,
) -> UseCoroutineBuilder<'a, O, M> {
let inner = cx.use_hook(|_| {
/// ## Global State
#[allow(clippy::mut_from_ref)]
pub fn use_coroutine<O: 'static>(cx: &ScopeState) -> &mut UseCoroutine<O, ()> {
cx.use_hook(|_| {
//
UseCoroutine {
val: Cell::new(None),
rx: Cell::new(None),
tx: None,
first_run: true,
deps: vec![],
dep_cnt: 0,
needs_regen: false,
auto_start: true,
}
});
UseCoroutineBuilder { cx, inner }
}
pub struct UseCoroutineBuilder<'a, O, M = ()> {
cx: &'a ScopeState,
inner: &'a mut UseCoroutine<O, M>,
}
impl<'a, O: 'static, M> UseCoroutineBuilder<'a, O, M> {
// fn with_channel<I>(self) -> UseCoroutineBuilder<'a, O, I> {
// UseCoroutineBuilder {
// cx: self.cx,
// inner: self.inner,
// }
// }
fn build<F: Future<Output = O>>(mut self, f: impl FnOnce() -> F) -> &'a UseCoroutine<O, ()> {
todo!()
}
fn build_channel<F: Future<Output = O>>(
mut self,
f: impl FnOnce(UnboundedReceiver<M>) -> F,
) -> &'a UseCoroutine<O, M> {
todo!()
}
pub fn use_dep(mut self) -> Self {
self
}
/// Provide the channel to downstream consumers
pub fn provide_context(mut self) -> Self {
self
}
pub fn auto_start(mut self, start: bool) -> Self {
// if start && self.inner.run_count.get() == 1 {
// self.start();
// }
self
}
})
}
pub struct UseCoroutine<O, M = ()> {
val: Cell<Option<O>>,
rx: Cell<Option<UnboundedReceiver<M>>>,
tx: Option<UnboundedSender<M>>,
first_run: bool,
deps: Vec<Box<dyn Any>>,
dep_cnt: usize,
needs_regen: bool,
auto_start: bool,
}
pub enum FutureState<'a, T> {
Pending,
Complete(&'a T),
Regenerating(&'a T), // the old value
}
impl<O> UseCoroutine<O, ()> {
/// explicitly set the type of the channel used by the coroutine
fn with_channel<S>(&mut self) -> &mut UseCoroutine<O, S> {
if self.first_run {
// self.provide_context()
}
todo!()
}
/// explicitly set the type of the channel used by the coroutine
fn with_channel_isolate<S>(&mut self) -> &mut UseCoroutine<O, S> {
todo!()
}
}
impl<O, M> UseCoroutine<O, M> {
pub fn is_running(&self) -> bool {
false
// self.inner.running.get()
// self.running.get()
}
pub fn start(&self) {
// if !self.is_running() {
// if let Some(mut fut) = self.create_fut.take() {
// let fut = fut();
// let ready_handle = self.inner.running.clone();
// let ready_handle = self.running.clone();
// let task = self.cx.push_future(async move {
// ready_handle.set(true);
@ -105,7 +92,7 @@ impl<O, M> UseCoroutine<O, M> {
// ready_handle.set(false);
// });
// self.inner.task_id.set(Some(task));
// self.task_id.set(Some(task));
// }
// }
}
@ -121,11 +108,55 @@ impl<O, M> UseCoroutine<O, M> {
// todo: wire these up, either into the task system or into the coroutine system itself
// we would have change how we poll the coroutine and how its awaken
fn build<F: Future<Output = O>>(&mut self, f: impl FnOnce(UnboundedReceiver<M>) -> F) -> &Self {
self.first_run = false;
if self.auto_start || self.needs_regen {
//
}
self
}
pub fn auto_start(mut self, start: bool) -> Self {
// if start && self.run_count.get() == 1 {
// self.start();
// }
self
}
/// Add this value to the dependency list
///
/// This is a hook and should be called during the initial hook process.
/// It should •not• be called in a conditional.
pub fn with_dep<F: 'static + PartialEq + Clone>(&mut self, dependency: &F) -> &mut Self {
if let Some(dep) = self.deps.get_mut(self.dep_cnt) {
if let Some(saved_dep) = dep.downcast_mut::<F>() {
if dependency != saved_dep {
*saved_dep = dependency.clone();
self.needs_regen = true;
}
};
} else {
self.deps.push(Box::new(dependency.to_owned()));
self.needs_regen = true;
}
self
}
pub fn restart_if(&self, f: impl FnOnce() -> bool) -> &Self {
self
}
// pub fn resume(&self) {}
// pub fn stop(&self) {}
// pub fn restart(&self) {}
}
pub struct CoroutineContext<T> {
tx: UnboundedSender<T>,
}
#[cfg(test)]
mod tests {
#![allow(unused)]
@ -135,246 +166,16 @@ mod tests {
use dioxus_core::prelude::*;
use futures_util::StreamExt;
fn app(cx: Scope) -> Element {
let poll_tasks = use_coroutine(&cx).auto_start(false).build(|| async {
loop {
println!("polling tasks");
}
});
todo!()
}
fn app_with_channel(cx: Scope) -> Element {
// let poll_tasks = use_coroutine(&cx).build_channel(|mut rx| async move {
// while let Some(msg) = rx.next().await {
// println!("polling tasks: {}", msg);
// }
// });
let poll_tasks =
use_coroutine(&cx).build_channel(|mut rx: UnboundedReceiver<()>| async move {
fn app(cx: Scope, name: String) -> Element {
let task = use_coroutine(&cx)
.with_dep(&name)
.with_channel::<i32>()
.build(|mut rx| async move {
while let Some(msg) = rx.next().await {
println!("polling tasks: {:?}", msg);
println!("got message: {}", msg);
}
});
// poll_tasks.send(10);
todo!()
None
}
}
mod use2 {
#![allow(missing_docs)]
use dioxus_core::{ScopeState, TaskId};
use std::{
any::Any,
cell::{Cell, RefCell},
future::Future,
rc::Rc,
};
/// A future that resolves to a value.
///
/// This runs the future only once - though the future may be regenerated
/// through the [`UseFuture::restart`] method.
///
/// This is commonly used for components that cannot be rendered until some
/// asynchronous operation has completed.
///
///
///
///
///
pub fn use_future<'a>(
// pub fn use_future<'a, T: 'static, F: Future<Output = T> + 'static>(
cx: &'a ScopeState,
) -> &'a UseFuture<()> {
// let state = cx.use_hook(move |_| UseFuture {
// update: cx.schedule_update(),
// needs_regen: Cell::new(true),
// slot: Rc::new(Cell::new(None)),
// value: None,
// task: None,
// pending: true,
// dep_cont: Cell::new(0),
// deps: RefCell::new(Vec::new()),
// first_time: true,
// });
// if let Some(value) = state.slot.take() {
// state.value = Some(value);
// state.task = None;
// }
// if state.needs_regen.get() {
// // We don't need regen anymore
// state.needs_regen.set(false);
// state.pending = false;
// // Create the new future
// let fut = new_fut();
// // Clone in our cells
// let slot = state.slot.clone();
// let updater = state.update.clone();
// state.task = Some(cx.push_future(async move {
// let res = fut.await;
// slot.set(Some(res));
// updater();
// }));
// }
// state.first_time = false;
// state
// new_fut: impl FnOnce() -> F,
todo!()
}
pub enum FutureState<'a, T> {
Pending,
Complete(&'a T),
Regenerating(&'a T), // the old value
}
pub struct UseFuture<T> {
update: Rc<dyn Fn()>,
needs_regen: Cell<bool>,
value: Option<T>,
pending: bool,
slot: Rc<Cell<Option<T>>>,
task: Option<TaskId>,
deps: RefCell<Vec<Box<dyn Any>>>,
dep_cont: Cell<usize>,
first_time: bool,
}
impl<T> UseFuture<T> {
pub fn restart(&self) {
self.needs_regen.set(true);
(self.update)();
}
// clears the value in the future slot without starting the future over
pub fn clear(&self) -> Option<T> {
(self.update)();
self.slot.replace(None)
}
// Manually set the value in the future slot without starting the future over
pub fn set(&self, new_value: T) {
self.slot.set(Some(new_value));
self.needs_regen.set(true);
(self.update)();
}
pub fn value(&self) -> Option<&T> {
self.value.as_ref()
}
pub fn state(&self) -> FutureState<T> {
// self.value.as_ref()
FutureState::Pending
}
/// Add this value to the dependency list
///
/// This is a hook and should be called during the initial hook process.
/// It should •not• be called in a conditional.
pub fn use_dep<F: 'static + PartialEq + Clone>(&self, dependency: &F) -> &Self {
let count = self.dep_cont.get();
let mut deps = self.deps.borrow_mut();
match deps.get_mut(count) {
Some(dep) => match dep.downcast_mut::<F>() {
Some(saved_dep) => {
if dependency != saved_dep {
*saved_dep = dependency.clone();
self.needs_regen.set(true);
}
}
None => {
if cfg!(debug_assertions) {
panic!("Tried to use a dependency for use_future outside of the use_future hook.");
}
}
},
None => deps.push(Box::new(dependency.to_owned())),
}
self
}
pub fn restart_if(&self, f: impl FnOnce() -> bool) -> &Self {
self
}
pub fn build<F>(&self, new_fut: impl FnOnce() -> F) {}
}
#[test]
fn test_use_future_deps() {
use dioxus_core::prelude::*;
struct MyProps {
val: String,
name: i32,
}
fn app(cx: Scope<MyProps>) -> Element {
let MyProps { val, name } = cx.props;
// let val = use_c(&cx)
// .use_dep(val)
// .restart_if(|| false)
// .use_dep(name)
// .build(|(val, name)| async move {});
// async fn fetch_thing(name: String, num: i32) -> String {
// format!("{} {}", name, num)
// }
// let val = use_future(&cx, || fetch_thing(val.clone(), *name))
// .with_dep(val)
// .with_dep(name)
// .restart_if(|| false);
None
}
}
// pub struct CoroutineBuilder<'a, const PARAM: usize> {
// deps: Vec<Box<dyn Any>>,
// cx: &'a ScopeState,
// }
// macro_rules! dep_impl {
// ($id1:literal to $id2:literal) => {
// impl<'a> CoroutineBuilder<'a, $id1> {
// pub fn use_dep<F: 'static + PartialEq + Clone>(
// mut self,
// dep: &F,
// ) -> CoroutineBuilder<'a, $id2> {
// self.deps.push(Box::new(dep.clone()));
// unsafe { std::mem::transmute(self) }
// }
// }
// };
// }
// dep_impl!(0 to 1);
// dep_impl!(1 to 2);
// dep_impl!(2 to 3);
// dep_impl!(3 to 4);
// dep_impl!(4 to 5);
// dep_impl!(5 to 6);
// dep_impl!(6 to 7);
// dep_impl!(7 to 8);
// dep_impl!(8 to 9);
}

View file

@ -1,42 +1,54 @@
use dioxus_core::{ScopeState, TaskId};
use std::{cell::Cell, future::Future, rc::Rc};
use std::{any::Any, cell::Cell, future::Future, rc::Rc};
pub fn use_future<'a, T: 'static, F: Future<Output = T> + 'static>(
/// A hook that provides a future that will resolve to a value.
///
/// Whenever the hooks dependencies change, the future will be re-evaluated.
/// If a future is pending when the dependencies change, the previous future
/// will be allowed to continue
///
///
/// - dependencies: a tuple of references to values that are PartialEq + Clone
pub fn use_future<'a, T: 'static, F: Future<Output = T> + 'static, D: UseFutureDep>(
cx: &'a ScopeState,
new_fut: impl FnOnce() -> F,
dependencies: D,
future: impl FnOnce(D::Out) -> F,
) -> &'a UseFuture<T> {
let state = cx.use_hook(move |_| {
//
UseFuture {
update: cx.schedule_update(),
needs_regen: Cell::new(true),
slot: Rc::new(Cell::new(None)),
value: None,
task: None,
}
let state = cx.use_hook(move |_| UseFuture {
update: cx.schedule_update(),
needs_regen: Cell::new(true),
slot: Rc::new(Cell::new(None)),
value: None,
task: Cell::new(None),
dependencies: Vec::new(),
});
if let Some(value) = state.slot.take() {
state.value = Some(value);
state.task = None;
state.task.set(None);
}
if state.needs_regen.get() {
if dependencies.clone().apply(&mut state.dependencies) || state.needs_regen.get() {
// We don't need regen anymore
state.needs_regen.set(false);
// Create the new future
let fut = new_fut();
let fut = future(dependencies.out());
// Clone in our cells
let slot = state.slot.clone();
let updater = state.update.clone();
let schedule_update = state.update.clone();
state.task = Some(cx.push_future(async move {
// Cancel the current future
if let Some(current) = state.task.take() {
cx.cancel_future(current);
}
state.task.set(Some(cx.push_future(async move {
let res = fut.await;
slot.set(Some(res));
updater();
}));
schedule_update();
})));
}
state
@ -47,15 +59,33 @@ pub struct UseFuture<T> {
needs_regen: Cell<bool>,
value: Option<T>,
slot: Rc<Cell<Option<T>>>,
task: Option<TaskId>,
task: Cell<Option<TaskId>>,
dependencies: Vec<Box<dyn Any>>,
}
pub enum UseFutureState<'a, T> {
Pending,
Complete(&'a T),
Reloading(&'a T),
}
impl<T> UseFuture<T> {
/// Restart the future with new dependencies.
///
/// Will not cancel the previous future, but will ignore any values that it
/// generates.
pub fn restart(&self) {
self.needs_regen.set(true);
(self.update)();
}
/// Forcefully cancel a future
pub fn cancel(&self, cx: &ScopeState) {
if let Some(task) = self.task.take() {
cx.cancel_future(task);
}
}
// clears the value in the future slot without starting the future over
pub fn clear(&self) -> Option<T> {
(self.update)();
@ -69,7 +99,139 @@ impl<T> UseFuture<T> {
(self.update)();
}
/// Return any value, even old values if the future has not yet resolved.
///
/// If the future has never completed, the returned value will be `None`.
pub fn value(&self) -> Option<&T> {
self.value.as_ref()
}
/// Get the ID of the future in Dioxus' internal scheduler
pub fn task(&self) -> Option<TaskId> {
self.task.get()
}
/// Get the current stateof the future.
pub fn state(&self) -> UseFutureState<T> {
match (&self.task.get(), &self.value) {
// If we have a task and an existing value, we're reloading
(Some(_), Some(val)) => UseFutureState::Reloading(val),
// no task, but value - we're done
(None, Some(val)) => UseFutureState::Complete(val),
// no task, no value - something's wrong? return pending
(None, None) => UseFutureState::Pending,
// Task, no value - we're still pending
(Some(_), None) => UseFutureState::Pending,
}
}
}
pub trait UseFutureDep: Sized + Clone {
type Out;
fn out(&self) -> Self::Out;
fn apply(self, state: &mut Vec<Box<dyn Any>>) -> bool;
}
impl UseFutureDep for () {
type Out = ();
fn out(&self) -> Self::Out {}
fn apply(self, _state: &mut Vec<Box<dyn Any>>) -> bool {
false
}
}
pub trait Dep: 'static + PartialEq + Clone {}
impl<T> Dep for T where T: 'static + PartialEq + Clone {}
macro_rules! impl_dep {
(
$($el:ident=$name:ident,)*
) => {
impl< $($el),* > UseFutureDep for ($(&$el,)*)
where
$(
$el: Dep
),*
{
type Out = ($($el,)*);
fn out(&self) -> Self::Out {
let ($($name,)*) = self;
($((*$name).clone(),)*)
}
#[allow(unused)]
fn apply(self, state: &mut Vec<Box<dyn Any>>) -> bool {
let ($($name,)*) = self;
let mut idx = 0;
let mut needs_regen = false;
$(
match state.get_mut(idx).map(|f| f.downcast_mut::<$el>()).flatten() {
Some(val) => {
if *val != *$name {
*val = $name.clone();
needs_regen = true;
}
}
None => {
state.push(Box::new($name.clone()));
needs_regen = true;
}
}
idx += 1;
)*
needs_regen
}
}
};
}
impl_dep!(A = a,);
impl_dep!(A = a, B = b,);
impl_dep!(A = a, B = b, C = c,);
impl_dep!(A = a, B = b, C = c, D = d,);
impl_dep!(A = a, B = b, C = c, D = d, E = e,);
impl_dep!(A = a, B = b, C = c, D = d, E = e, F = f,);
#[cfg(test)]
mod tests {
use super::*;
#[allow(unused)]
#[test]
fn test_use_future() {
use dioxus_core::prelude::*;
struct MyProps {
a: String,
b: i32,
c: i32,
d: i32,
e: i32,
}
fn app(cx: Scope<MyProps>) -> Element {
// should only ever run once
let fut = use_future(&cx, (), |_| async move {
//
});
// runs when a is changed
let fut = use_future(&cx, (&cx.props.a,), |(a,)| async move {
//
});
// runs when a or b is changed
let fut = use_future(&cx, (&cx.props.a, &cx.props.b), |(a, b)| async move {
//
});
None
}
}
}