use wasm_bindgen::prelude::*;
pub trait CustomElementMetadata {
const CUSTOM_ELEMENT_NAME: &'static str;
const STATICS: &'static [&'static str] = [].as_slice();
const TYPE_NAME: &'static str = std::any::type_name::<Self>();
fn struct_name() -> &'static str {
match &Self::TYPE_NAME.rfind(':') {
Some(pos) => &Self::TYPE_NAME[pos + 1..],
None => Self::TYPE_NAME,
}
}
}
#[wasm_bindgen(inline_js = "
export function bootstrap(psp, name, clsname, statics) {
const cls = psp[clsname];
const proto = cls.prototype;
class x extends HTMLElement {
constructor() {
super();
this._instance = new cls(this);
}
}
const names = Object.getOwnPropertyNames(proto);
for (const key of names) {
if ('get' in Object.getOwnPropertyDescriptor(proto, key)) {
Object.defineProperty(x.prototype, key, {
get: function() {
return this._instance[key];
}
});
} else {
Object.defineProperty(x.prototype, key, {
value: function(...args) {
return this._instance[key].call(this._instance, ...args);
}
});
}
}
for (const key of statics) {
Object.defineProperty(x, key, {
value: function(...args) {
return psp[key].call(psp, ...args);
}
});
}
customElements.define(name, x);
}
")]
extern "C" {
#[wasm_bindgen(js_name = "bootstrap")]
fn js_bootstrap(psp: &JsValue, name: &str, cls: &str, statics: js_sys::Array) -> JsValue;
}
pub fn define_web_component<T: CustomElementMetadata>(module: &JsValue) {
js_bootstrap(
module,
T::CUSTOM_ELEMENT_NAME,
T::struct_name(),
T::STATICS.iter().cloned().map(JsValue::from).collect(),
);
}