Actuate

A high-performance and borrow-checker friendly framework for declarative programming in Rust. This crate provides a generic library that lets you define reactive components (also known as composables).

Features

• Declarative scenes and UI for Bevy
• Efficient and borrow-checker friendly state management: Manage state with components and hooks, all using zero-cost smart pointers
• Generic core for custom backends

use actuate::prelude::*;

#[derive(Data)]
struct Counter {
    start: i32,
}

impl Compose for Counter {
    fn compose(cx: Scope<Self>) -> impl Compose {
        let count = use_mut(&cx, || cx.me().start);

        material_ui((
            text::headline(format!("High five count: {}", count)),
            button(text::label("Up high")).on_click(move || SignalMut::update(count, |x| *x += 1)),
            button(text::label("Down low")).on_click(move || SignalMut::update(count, |x| *x -= 1)),
            if *count == 0 {
                Some(text::label("Gimme five!"))
            } else {
                None
            },
        ))
        .align_items(AlignItems::Center)
        .justify_content(JustifyContent::Center)
    }
}

Borrowing

Composables can borrow from their ancestors, as well as state.

use actuate::prelude::*;

#[derive(Data)]
struct User<'a> {
    // `actuate::Cow` allows for either a borrowed or owned value.
    name: Cow<'a, String>,
}

impl Compose for User<'_> {
    fn compose(cx: Scope<Self>) -> impl Compose {
        text::headline(cx.me().name.to_string())
    }
}

#[derive(Data)]
struct App {
    name: String
}

impl Compose for App {
    fn compose(cx: Scope<Self>) -> impl Compose {
        // Get a mapped reference to the app's `name` field.
        let name = Signal::map(cx.me(), |me| &me.name).into();

        User { name }
    }
}

Installation

To add this crate to your project:

cargo add actuate --features full

For more feature flags, see the crate documentation for features.

Inspiration

This crate is inspired by Xilem and uses a similar approach to type-safe reactivity. The main difference with this crate is the concept of scopes, components store their state in their own scope and updates to that scope re-render the component.

State management is inspired by React and Dioxus.

Previous implementations were in Concoct but were never very compatible with lifetimes.