Spawning Futures
The use_future and use_coroutine hooks are useful if you want to unconditionally spawn the future. Sometimes, though, you'll want to only spawn a future in response to an event, such as a mouse click. For example, suppose you need to send a request when the user clicks a "log in" button. For this, you can use cx.spawn:
let logged_in = use_state(cx, || false);
let log_in = move |_| {
cx.spawn({
let logged_in = logged_in.to_owned();
async move {
let resp = reqwest::Client::new()
.post("http://example.com/login")
.send()
.await;
match resp {
Ok(_data) => {
println!("Login successful!");
logged_in.set(true);
}
Err(_err) => {
println!(
"Login failed - you need a login server running on localhost:8080."
)
}
}
}
});
};
cx.render(rsx! {
button {
onclick: log_in,
"Login",
}
})Note:
spawnwill always spawn a new future. You most likely don't want to call it on every render.
Calling spawn will give you a JoinHandle which lets you cancel or pause the future.
Spawning Tokio Tasks
Sometimes, you might want to spawn a background task that needs multiple threads or talk to hardware that might block your app code. In these cases, we can directly spawn a Tokio task from our future. For Dioxus-Desktop, your task will be spawned onto Tokio's Multithreaded runtime:
cx.spawn(async {
let _ = tokio::spawn(async {}).await;
let _ = tokio::task::spawn_local(async {
// some !Send work
})
.await;
});