nicoburniske / leptos_image

An optimized Image component for Leptos

Leptos Image

Crafted with inspiration from Next.js

Images make a substantial impact on the size and performance of a website, so why not get them right?

Enter Leptos <Image/>, a component that enhances the standard HTML <img> element with automatic image optimization features.

• Size Optimization: Resize images, and use modern .webp format for optimal size and quality.
• Low-Quality Image Placeholders (LQIP): With this feature, the Image component embeds SVGs, extracted from the original images, into the initial SSR HTML. This placeholder is shown while the optimized version is loading.
• Faster Page Load: Prioritize key images, such as those contributing to the Largest Contentful Paint (LCP) with the priority prop. The component adds a preload <link> to the document head, improving load times and enhancing your site's performance.

Installation

Add leptos_image via cargo:

cargo add leptos_image

Add the SSR Feature under [features] in your Cargo.toml

[features]
ssr = [
    "leptos_image/ssr",
    # ...
 ]

Quick Start

REQUIRES SSR + AXUM

First add the provider to the base of your Leptos App.

use leptos_image::*;

#[component]
pub fn App(cx: Scope) -> impl IntoView {
    provide_image_context(cx);

    view!{cx,
        // ...
    }
}

Next go to your SSR Main Function in main.rs

Before you create your router, call the cache_app_images function with the project root. This will cache all the images in your app, and generate the LQIPs.

If you have a lot of images, then you should probably only call this function in production because it will delay your server startup.

If you don't include this function, then image caching will happen at runtime.

use leptos::*;
use leptos_image::*;

let conf = get_configuration(None).await.unwrap();
let leptos_options = conf.leptos_options;
let root = leptos_options.site_root.clone();

use leptos_image::cache::cache_app_images;

cache_app_images(root, |cx: Scope| view! {cx, <App/>}, 2, || (), || ())
    .await
    .expect("Failed to cache images");

Next add an endpoint to your router that serves the cached images. For now, the endpoint path must be /cache/image and is not configurable

use axum::{routing::{get, post}, Router};

let router = ...

router.route("/cache/image", get(image_cache_handler));

The final router should look something like this!

let router = Router::new()
        .route("/api/*fn_name", post(leptos_axum::handle_server_fns))
        .leptos_routes(&leptos_options, routes, |cx| {
            view! { cx,
                <App/>
            }
        })
        // Here's the new route!
        .route("/cache/image", get(image_cache_handler))
        .with_state(leptos_options);

Now you can use the Image Component anywhere in your app!

#[component]
pub fn MyPage(cx: Scope) -> impl IntoView {
    view! { cx,
        <Title text="This Rust thing is pretty great"/>
        <Image
            src="/cute_ferris.png"
            blur=true
            width=750
            height=500
            quality=85
        />
    }
}

And that's it. You're all set to use the Image Component.

Caveats:

• Images will only be retrieved from routes that are non-dynamic (meaning not api/post/:id in Route path).
• Images can take a few seconds to optimize, meaning first startup of server will be slower.
• Actix Support is coming soon!