Function use_hook

pub fn use_hook<State>(initializer: impl FnOnce() -> State) -> State
where
    State: Clone + 'static,

Store a value between renders. The foundational hook for all other hooks.

Accepts an initializer closure, which is run on the first use of the hook (typically the initial render). use_hook will return a clone of the value on every render.

In order to clean up resources you would need to implement the Drop trait for an inner value stored in a RC or similar (Signals for instance), as these only drop their inner value once all references have been dropped, which only happens when the component is dropped.

Example

use dioxus::prelude::*;

// prints a greeting on the initial render
pub fn use_hello_world() {
    use_hook(|| println!("Hello, world!"));
}

Custom Hook Example

use dioxus::prelude::*;

pub struct InnerCustomState(usize);

impl Drop for InnerCustomState {
    fn drop(&mut self){
        println!("Component has been dropped.");
    }
}

#[derive(Clone, Copy)]
pub struct CustomState {
    inner: Signal<InnerCustomState>
}

pub fn use_custom_state() -> CustomState {
    use_hook(|| CustomState {
        inner: Signal::new(InnerCustomState(0))
    })
}