servable 0.0.4

A tiny web stack featuring htmx, Axum, Rust, and Maud.
Documentation

Servable: a simple web framework

CI Cargo API reference

A minimal, convenient web micro-framework built around htmx, Axum, and Maud.
This powers my homepage. See example usage here.

Features

servable provides abstractions that implement common utilities needed by an http server.

  • response headers and cache-busting utilities
  • client device detection (mobile / desktop)
  • server-side image optimization (see the image feature below)
  • ergonomic htmx integration (see htmx-* features below)

Quick Start

use servable::{ServableRouter, servable::StaticAsset, mime::MimeType};

#[tokio::main]
async fn main() {
	let route = ServableRouter::new()
		.add_page(
			"/hello",
			StaticAsset {
				bytes: b"Hello, World!",
				mime: MimeType::Text,
			},
		);

	// usual axum startup routine
	let app = route.into_router();
	let listener = tokio::net::TcpListener::bind("0.0.0.0:3000")
		.await
		.unwrap();

	axum::serve(listener, app).await.unwrap();
}

Core Concepts

The Servable trait

The Servable trait is the foundation of this stack.
servable provides implementations for a few common servables:

  • StaticAsset, for static files like CSS, JavaScript, images, or plain bytes:

     use servable::{StaticAsset, mime::MimeType};

 let asset = StaticAsset {
 	bytes: b"body { color: red; }",
 	mime: MimeType::Css,
 	ttl: StaticAsset::DEFAULT_TTL
 };

  • Redirect, for simple http redirects:

     use servable::Redirect;

 let redirect = Redirect::new("/new-location").unwrap();

  • HtmlPage, for dynamically-rendered HTML pages

     use servable::{HtmlPage, PageMetadata};
 use maud::html;
 use std::pin::Pin;

 let page = HtmlPage::default()
 	.with_meta(PageMetadata {
 		title: "My Page".into(),
 		description: Some("A great page".into()),
 		..Default::default()
 	})
 	.with_render(|_page, ctx| {
 		Box::pin(async move {
 			html! {
 				h1 { "Welcome!" }
 				p { "Route: " (ctx.route) }
 			}
 		})
 	});

    HtmlPage automatically generates a <head> and wraps its rendered html in <html><body>.

ServableRouter

A ServableRouter exposes a collection of Servables under different routes. It implements tower's Service trait, and can be easily be converted into an Axum Router. Construct one as follows:

# use servable::{ServableRouter, StaticAsset, mime::MimeType};
# let home_page = StaticAsset { bytes: b"home", mime: MimeType::Html, ttl: StaticAsset::DEFAULT_TTL};
# let about_page = StaticAsset { bytes: b"about", mime: MimeType::Html, ttl: StaticAsset::DEFAULT_TTL };
# let stylesheet = StaticAsset { bytes: b"css", mime: MimeType::Css, ttl: StaticAsset::DEFAULT_TTL };
# let custom_404_page = StaticAsset { bytes: b"404", mime: MimeType::Html, ttl: StaticAsset::DEFAULT_TTL };
let route = ServableRouter::new()
	.add_page("/", home_page)
	.add_page("/about", about_page)
	.add_page("/style.css", stylesheet)
	.with_404(custom_404_page); // override default 404

Features

  • image: enable image transformation via query parameters. This makes tokio a dependency.
    When this is enabled, all StaticAssets with a valid mimetype can take an optional t= query parameter.
    See the TransformerEnum in this crate's documentation for details.

    When image is enabled, the image below...

     # use servable::{ServableRouter, StaticAsset, mime::MimeType};
 let route = ServableRouter::new()
 	.add_page(
 		"/image.png",
 		StaticAsset {
 			bytes: b"fake image data",
 			mime: MimeType::Png,
 			ttl: StaticAsset::DEFAULT_TTL
 		}
 	);

    ...may be accessed as follows:

     # Original image
 GET /image.png

 # Resize to max 800px on longest side
 GET /image.png?t=maxdim(800,800)

 # Crop to a 400x400 square at the center of the image
 GET /image.png?t=crop(400,400,c)

 # Chain transformations and transcode
 GET /image.png?t=maxdim(800,800);crop(400,400);format(webp)

  • htmx-2.0.8: Include htmx sources in the compiled executable.
    Use as follows:

     # use servable::ServableRouter;
 # #[cfg(feature = "htmx-2.0.8")]
 let route = ServableRouter::new()
 	.add_page("/htmx.js", servable::HTMX_2_0_8)
 	.add_page("/htmx-json-enc.js", servable::EXT_JSON_1_19_12);

Caching and cache-busting

Control caching behavior per servable:

use chrono::TimeDelta;
use servable::HtmlPage;

let page = HtmlPage::default()
	.with_ttl(Some(TimeDelta::hours(1)))
	.with_private(false);

Headers are automatically generated:

  • Cache-Control: public, max-age=3600 (default)
  • Cache-Control: private, max-age=31536000 (if private is true)

We also provide a static CACHE_BUST_STR, which may be formatted into urls to force cache refresh whenever the server is restarted:

use chrono::TimeDelta;
use servable::{HtmlPage, CACHE_BUST_STR, ServableWithRoute, StaticAsset, ServableRouter};
use servable::mime::MimeType;

pub static HTMX: ServableWithRoute<StaticAsset> = ServableWithRoute::new(
	|| format!("/{}/main.css", *CACHE_BUST_STR),
	StaticAsset {
		bytes: "div{}".as_bytes(),
		mime: MimeType::Css,
		ttl: StaticAsset::DEFAULT_TTL,
	},
);


let route = HTMX.route();
println!("Css is at {route}");

let router = ServableRouter::new()
	.add_page_with_route(&HTMX);

TODO:

  • cache-busting fonts in css is not possible, we need to dynamic replace urls