web-sys: DOM hello world

View full source code or view the compiled example online

Using web-sys we're able to interact with all the standard web platform methods, including those of the DOM! Here we take a look at a simple "Hello, world!" which manufactures a DOM element in Rust, customizes it, and then appends it to the page.

Cargo.toml

You can see here how we depend on web-sys and activate associated features to enable all the various APIs:

[package]
name = "dom"
version = "0.1.0"
authors = ["The wasm-bindgen Developers"]
edition = "2018"

[lib]
crate-type = ["cdylib"]

[dependencies]
wasm-bindgen = "0.2.83"

[dependencies.web-sys]
version = "0.3.4"
features = [
  'Document',
  'Element',
  'HtmlElement',
  'Node',
  'Window',
]

src/lib.rs

# #![allow(unused_variables)]
#fn main() {
use wasm_bindgen::prelude::*;

// Called by our JS entry point to run the example
#[wasm_bindgen(start)]
pub fn run() -> Result<(), JsValue> {
    // Use `web_sys`'s global `window` function to get a handle on the global
    // window object.
    let window = web_sys::window().expect("no global `window` exists");
    let document = window.document().expect("should have a document on window");
    let body = document.body().expect("document should have a body");

    // Manufacture the element we're gonna append
    let val = document.create_element("p")?;
    val.set_text_content(Some("Hello from Rust!"));

    body.append_child(&val)?;

    Ok(())
}

#}