css-in-rs

A library for embedding dynamic CSS in Rust (wasm); inspired by cssinjs/JSS

This crate is designed to be framework-independent. It currently provides integrations for Dioxus, which is disabled by default.

Use case

This crate allows to develop reusable components for the web which bundle their own styles. Dead-Code-Analysis works as usually with Rust: If you do not need a certain component, its styles won't be embedded in the final binary.

The classnames are generated at runtime to avoid collisions (i.e. css-123).

Basic idea

The make_styles! procmacro allows you to write CSS-like style sheets directly in Rust. You can use normal class names without worrying about collisions. Even if another component uses the same name, it does not matter. The procmacro automatically determines the classnames from the style and generates a helper class containing the real class names.

Example (Dioxus):

#![allow(non_snake_case)]

use css_in_rs::{Classes, EmptyTheme, make_styles, use_style_provider_root};
use dioxus::prelude::*;

make_styles! {
    (_theme: EmptyTheme) -> MyClasses {
        red_text {
            color: "red",
            margin: "5px",
        },
        "button" {
            margin: "5px",
            padding: "5px",
            width: "10em",
        },
        "button.primary" {
            border: "2px solid red",
        },
        "button.disabled" { // Shows a rust warning: "field never read"
            disabled: true,
        },
    }
}

fn Demo(cx: Scope) -> Element {
    let classes: &MyClasses = MyClasses::use_style(cx);

    render! {
        div {
            class: &classes.red_text as &str,
            "This text is supposed to be red.",
        }
        button {
            class: &classes.primary as &str,
            "Click me",
        }
    }
}

fn App(cx: Scope) -> Element {
    let document = web_sys::window().unwrap().document().unwrap();
    let root = document.get_element_by_id("main").unwrap();
    
    use_style_provider_root(cx, &root, || EmptyTheme);

    cx.render(rsx! {
        Demo {}
    })
}

fn main() {
    // launch the web app
    dioxus_web::launch(App);
}