Crate leptos_maybe_callback

Optional callbacks for Leptos.

Example

Component with Optional Callback Prop

Define a component that accepts an optional callback using #[prop(into, optional)]. This allows passing a closure, a Callback, or omitting the prop.

use leptos::{ev::MouseEvent, prelude::*};
use leptos_maybe_callback::MaybeCallback;

/// A button component with an optional `onclick` callback.
#[component]
pub fn Button(
    #[prop(into, optional)]
    onclick: MaybeCallback<MouseEvent>,
) -> impl IntoView {
    view! {
        <button on:click=onclick.into_handler()>
            "Click me"
        </button>
    }
}

Using the Component with a Closure

Use the Button component and provide a closure for the onclick prop.

use leptos::prelude::*;
use leptos_maybe_callback::MaybeCallback;

/// Parent component using `Button` with a closure.
#[component]
pub fn ButtonWithClosure() -> impl IntoView {
    view! {
        <div>
            <Button onclick=|_| log::info!("Clicked via closure!") />
            <Button />
        </div>
    }
}

Using the Component with a Callback

Alternatively, pass a Callback as the onclick prop.

use leptos::{ev::MouseEvent, prelude::*};
use leptos_maybe_callback::MaybeCallback;

/// Parent component using `Button` with a `Callback`.
#[component]
pub fn ButtonWithCallback() -> impl IntoView {
    let on_click = Callback::new(|event: MouseEvent| {
        log::info!("Clicked with event: {:?}", event);
    });

    view! {
        <div>
            <Button onclick=on_click />
            <Button />
        </div>
    }
}

Omitting the Callback

If no callback is needed, omit the onclick prop or pass None.

use leptos::{ev::MouseEvent, prelude::*};
use leptos_maybe_callback::MaybeCallback;

/// Parent component using `Button` without a callback.
#[component]
pub fn ButtonWithoutCallback() -> impl IntoView {
    view! {
        <div>
            <Button />
            <Button onclick={None::<Callback<MouseEvent>>} />
        </div>
    }
}

Structs

MaybeCallback

A wrapper around an optional callback that provides convenient conversion and method call semantics.