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2022-10-02 18:16:10 -04:00
use js_sys::Function;
use wasm_bindgen::JsValue;
use web_sys::window;
type Result<T> = std::result::Result<T, JsValue>;
pub trait CustomElementImpl {
fn class_name() -> &'static str;
fn element_name() -> &'static str;
}
pub fn define_web_component<T: CustomElementImpl>() -> Result<JsValue> {
let body = format!(
"class {name} extends HTMLElement {{
constructor() {{
super();
}}
}}
customElements.define(\"{element_name}\", {name});
var element = customElements.get(\"{element_name}\");
return element;",
name = T::class_name(),
element_name = T::element_name(),
);
let fun = Function::new_no_args(&body);
Ok(fun.call0(&window().unwrap())?)
}
#[cfg(test)]
mod tests {
use super::*;
use wasm_bindgen::{prelude::*, JsCast};
use wasm_bindgen_test::wasm_bindgen_test;
wasm_bindgen_test::wasm_bindgen_test_configure!(run_in_browser);
pub struct MyElementImpl();
impl CustomElementImpl for MyElementImpl {
fn class_name() -> &'static str {
"MyElement"
}
fn element_name() -> &'static str {
"my-element"
}
}
#[wasm_bindgen]
extern "C" {
#[wasm_bindgen(js_namespace = console, js_name = log)]
pub fn log(message: String);
#[wasm_bindgen(js_namespace = console, js_name = log)]
pub fn log_with_val(message: String, val: &JsValue);
}
#[wasm_bindgen_test]
fn test_component_definition() {
let obj = define_web_component::<MyElementImpl>().expect("Failed to define web component");
let fun = obj.dyn_ref::<Function>().unwrap();
assert_eq!(fun.name(), MyElementImpl::class_name());
let element = window()
.unwrap()
.document()
.unwrap()
.create_element(MyElementImpl::element_name())
.unwrap();
assert_eq!(
element.tag_name().to_uppercase(),
MyElementImpl::element_name().to_uppercase()
);
}
}