Function use_map

pub fn use_map<'hook, K, V>(
    initial_value: HashMap<K, V>,
) -> impl 'hook + Hook<Output = UseMapHandle<K, V>>
where
    K: 'static + 'hook,
    V: 'static + 'hook,

A hook that tracks a hash map and provides methods to modify it.

Example

use yew_hooks::prelude::*;

#[function_component(UseMap)]
fn map() -> Html {
    let map = use_map(HashMap::from([
        ("Mercury", 0.4),
        ("Venus", 0.7),
        ("Earth", 1.0),
        ("Mars", 1.5),
    ]));

    let onset = {
        let map = map.clone();
        Callback::from(move |_| map.set(HashMap::from([("Moon", 0.8), ("Earth", 1.0)])))
    };
    let oninsert = {
        let map = map.clone();
        Callback::from(move |_| {
            let _ = map.insert("Jupiter", 2.1);
        })
    };
    let onupdate = {
        let map = map.clone();
        Callback::from(move |_| map.update(&"Earth", 1.1))
    };
    let onremove = {
        let map = map.clone();
        Callback::from(move |_| {
            let _ = map.remove(&"Moon");
        })
    };
    let onretain = {
        let map = map.clone();
        Callback::from(move |_| map.retain(|_k, v| v > &mut 1.0))
    };
    let onclear = {
        let map = map.clone();
        Callback::from(move |_| map.clear())
    };

    html! {
        <div>
            <button onclick={onset}>{ "Set" }</button>
            <button onclick={oninsert}>{ "Insert" }</button>
            <button onclick={onupdate}>{ "Update" }</button>
            <button onclick={onremove}>{ "Remove" }</button>
            <button onclick={onretain}>{ "Retain" }</button>
            <button onclick={onclear}>{ "Clear all" }</button>
            <p>
                <b>{ "Current value: " }</b>
            </p>
            {
                for map.current().iter().map(|(k, v)| {
                    html! {
                        <p><b>{ k }</b> {": "} { v }</p>
                    }
                })
            }
        </div>
    }
}

Note

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

pub fn use_map<K, V>(initial_value: HashMap<K, V>) -> UseMapHandle<K, V>
where
    K: 'static,
    V: 'static,
{
    /* implementation omitted */
}