Leptos-Use Guide

use_throttle_fn

Throttle execution of a function. Especially useful for rate limiting execution of handlers on events like resize and scroll.

Throttle is a spring that throws balls: After a ball flies out it needs some time to shrink back, so it cannot throw any more balls until it's ready.

Demo

Usage

use leptos::prelude::*;
use leptos_use::use_throttle_fn;

#[component]
fn Demo() -> impl IntoView {
let mut throttled_fn = use_throttle_fn(
    || {
        // do something, it will be called at most 1 time per second
    },
    1000.0,
);
view! {
    <button on:click=move |_| { throttled_fn(); }>
        "Smash me!"
    </button>
}
}

Please note that if the current component is cleaned up before the throttled callback is called, the throttled callback will not be called.

You can provide options when you use use_throttle_fn_with_options.

use leptos::prelude::*;
use leptos_use::{ThrottleOptions, use_throttle_fn_with_options};
#[component]
fn Demo() -> impl IntoView {
let throttled_fn = use_throttle_fn_with_options(
    || {
        // do something, it will be called at most 1 time per second
    },
    1000.0,
    ThrottleOptions::default()
        .leading(true)
        .trailing(true),
);
   view! { }
}

If you want to throttle a function that takes an argument there are also the versions use_throttle_fn_with_arg and use_throttle_fn_with_arg_and_options.

SendWrapped Return

The returned closure is a sendwrapped function. It can only be called from the same thread that called use_throttle_....

Server-Side Rendering

Internally this uses setTimeout which is not supported on the server. So usually calling a throttled function on the server will simply be ignored.

Feature

This function is only available if the crate feature use_throttle_fn is enabled

Source

SourceDemoDocs