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 response = use_state(cx, || String::from("...")); let log_in = move |_| { cx.spawn({ to_owned![response]; async move { let resp = reqwest::Client::new() .get("https://dioxuslabs.com") .send() .await; match resp { Ok(_data) => { log::info!("dioxuslabs.com responded!"); response.set("dioxuslabs.com responded!".into()); } Err(err) => { log::info!( "Request failed with error: {err:?}" ) } } } }); }; render! { button { onclick: log_in, "Response: {response}", } }
Note:
spawn
will 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; });