A standard library for the client-side Web

The goal of this crate is to provide Rust bindings to the Web APIs and to allow a high degree of interoperability between Rust and JavaScript.

Examples

You can directly embed JavaScript code into Rust:

let message = "Hello, 世界!";
let result = js! {
    alert( @{message} );
    return 2 + 2 * 2;
};

println!( "2 + 2 * 2 = {:?}", result );

Even closures are supported:

let print_hello = |name: String| {
    println!( "Hello, {}!", name );
};

js! {
    var print_hello = @{print_hello};
    print_hello( "Bob" );
    print_hello.drop(); // Necessary to clean up the closure on Rust's side.
}

You can also pass arbitrary structures thanks to serde:

#[derive(Serialize)]
struct Person {
    name: String,
    age: i32
}

js_serializable!( Person );

js! {
    var person = @{person};
    console.log( person.name + " is " + person.age + " years old." );
};

This crate also exposes a number of Web APIs, for example:

let button = document().query_selector( "#hide-button" ).unwrap();
button.add_event_listener( move |_: ClickEvent| {
    for anchor in document().query_selector_all( "#main a" ) {
        js!( @{anchor}.style = "display: none;"; );
    }
});

Design goals

Expose a full suite of Web APIs as exposed by web browsers.
Try to follow the original JavaScript conventions and structure as much as possible, except in cases where doing otherwise results in a clearly superior design.
Be a building block from which higher level frameworks and libraries can be built.
Make it convenient and easy to embed JavaScript code directly into Rust and to marshal data between the two.
Integrate with the wider Rust ecosystem, e.g. support marshaling of structs which implement serde's Serializable.
Put Rust in the driver's seat where a non-trivial Web application can be written without touching JavaScript at all.
Allow Rust to take part in the upcoming WebAssembly (re)volution.

Getting started

WARNING: This crate is still a work-in-progress. Things might not work. Things might break. The APIs are in flux. Please do not use it in production.

Add an asmjs target with rustup:

$ rustup target add asmjs-unknown-emscripten

Install cargo-web; it's not strictly necessary but it makes things more convenient:
```
$ cargo install cargo-web
```
Go into examples/todomvc and type:
```
$ cargo web start
```
Visit http://localhost:8000 with your browser.

License

Licensed under either of

Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Snippets of documentation which come from Mozilla Developer Network are covered under the CC-BY-SA, version 2.5 or later.

Contribution