Function use_previous 

pub fn use_previous<'hook, T>(
    value: T,
) -> impl 'hook + Hook<Output = UsePreviousHandle<T>>
where
    T: 'static + 'hook,

This hook returns the previous immutable ref to state or props.

Example

use yew_hooks::prelude::*;

#[function_component(UsePrevious)]
fn previous() -> Html {
    let state = use_state(|| 0);
    let previous_state = use_previous(state.clone());


    let onincrease = {
        let state = state.clone();
        Callback::from(move |_| state.set(*state + 1))
    };
    let ondecrease = {
        let state = state.clone();
        Callback::from(move |_| state.set(*state - 1))
    };
    
    html! {
        <div>
            <button onclick={onincrease}>{ "Increase" }</button>
            <button onclick={ondecrease}>{ "Decrease" }</button>
            <p>
                <b>{ "Current value: " }</b>
                { *state }
            </p>
            <p>
                <b>{ "Previous value: " }</b>
                { **previous_state }
            </p>
        </div>
    }
}

Note

When used in function components and hooks, this hook is equivalent to:

/// This hook returns the previous immutable ref to state or props.
///
/// # Example
///
/// ```rust
/// # use yew::prelude::*;
/// #
/// use yew_hooks::prelude::*;
///
/// #[function_component(UsePrevious)]
/// fn previous() -> Html {
///     let state = use_state(|| 0);
///     let previous_state = use_previous(state.clone());
///
///
///     let onincrease = {
///         let state = state.clone();
///         Callback::from(move |_| state.set(*state + 1))
///     };
///     let ondecrease = {
///         let state = state.clone();
///         Callback::from(move |_| state.set(*state - 1))
///     };
///
///     html! {
///         <div>
///             <button onclick={onincrease}>{ "Increase" }</button>
///             <button onclick={ondecrease}>{ "Decrease" }</button>
///             <p>
///                 <b>{ "Current value: " }</b>
///                 { *state }
///             </p>
///             <p>
///                 <b>{ "Previous value: " }</b>
///                 { **previous_state }
///             </p>
///         </div>
///     }
/// }
/// ```
pub fn use_previous<T>(value: T) -> UsePreviousHandle<T>
where
    T: 'static,
{
    /* implementation omitted */
}