The new syntax does not allow you to create an initial state without violating the hook creation rules

[RustGrow]

The new 0.6 syntax makes it impossible to activate the initial state of an application without breaking the rules for using hooks. Using the 0.5 application initial syntax, use_context_provider initializes the creation of the initial application state inside the function:

fn App() -> Element {
    use_context_provider(|| Signal::new("en".to_string()))
}

The new syntax is like a street with two red lights on it, where you can’t initialize state without breaking the hook rules, because launch is a closure and causes a hook error.

fn main () {
use_context_provider(|| Signal::new("en".to_string()))
launch(|| {
    rsx! {
        // Your component code here
    }
});
}

Has an error: hook called outside component or hook

launch(|| {
    use_context_provider(|| Signal::new("en".to_string()))
    rsx! {
        // Your component code here
    }
});

Has an errors hook called in a closure and hook called outside component or hook

Environment:

• Dioxus version: 0.6 from git
• Rust version: rustc 1.81.0
• OS info: win11
• App platform: web

[matthunz]

Would something like this work for you?

fn main () {
  // If you need to load from env vars or etc
  let locale = String::from("en");
  
  launch(move || {
    rsx! {
      App { locale: locale.clone() }
    }
  });
}

#[component]
fn App(locale: String) {
  use_context_provider(|| Signal::new(locale))
  
  // Your component code here
}

GlobalSignal might also fit your use case

[RustGrow]

It's the same thing

fn main() {
    dioxus_logger::init(Level::INFO).expect("failed to init logger");
    info!("starting app");
    launch(App);
}

fn App() -> Element {
    use_context_provider(|| Signal::new("en".to_string()));
    let mut lang: Signal<String> = use_context();

The new syntax replaces the code above

fn main() {   
    launch(|| {
        use_context_provider(|| Signal::new("en".to_string()));
        rsx! {}
    });
}

Evan says it's fine and the rules are not broken, but because the app is not directly defined as a component. dx check will constantly generate a signals violation error