wasm-bindgen/examples/dom/src/lib.rs

#![feature(proc_macro, wasm_custom_section, wasm_import_module)]

extern crate wasm_bindgen;

use wasm_bindgen::prelude::*;

// Definitions of the functionality available in JS, which wasm-bindgen will
// generate shims for today (and eventually these should be near-0 cost!)
//
// These definitions need to be hand-written today but the current vision is
// that we'll use WebIDL to generate this `extern` block into a crate which you
// can link and import. There's a tracking issue for this at
// https://github.com/rustwasm/wasm-bindgen/issues/42
//
// In the meantime these are written out by hand and correspond to the names and
// signatures documented on MDN, for example
#[wasm_bindgen]
extern "C" {
    type HTMLDocument;
    static document: HTMLDocument;
    #[wasm_bindgen(method)]
    fn createElement(this: &HTMLDocument, tagName: &str) -> Element;
    #[wasm_bindgen(method, getter)]
    fn body(this: &HTMLDocument) -> Element;

    type Element;
    #[wasm_bindgen(method, setter = innerHTML)]
    fn set_inner_html(this: &Element, html: &str);
    #[wasm_bindgen(method, js_name = appendChild)]
    fn append_child(this: &Element, other: Element);
}

// Called by our JS entry point to run the example
#[wasm_bindgen]
pub fn run() {
    let val = document.createElement("p");
    val.set_inner_html("Hello from Rust!");
    document.body().append_child(val);
}