astro/examples/hackernews/src/components/Toggle.astro

---
interface Props {
	open?: boolean;
}

const { open = false } = Astro.props;
---

<hn-toggle open={open ? '' : undefined}>
	<div class="toggle">
		<a>{open ? '[-]' : '[+] comments collapsed'}</a>
	</div>
	<ul class="comment-children">
		<slot />
	</ul>
</hn-toggle>

<style>
	hn-toggle[open] > .toggle {
		padding: 0;
		background-color: transparent;
		margin-bottom: -0.5em;
	}

	hn-toggle:not([open]) > .toggle {
		background-color: rgb(255 247 237);
	}
	hn-toggle:not([open]) ul {
		display: none;
	}

	.toggle {
		font-size: 0.9em;
		margin: 1em 0;
		padding: 0.3em 0.5em;
		border-radius: 4px;
	}

	a {
		color: rgb(51 65 85);
		cursor: pointer;
	}
</style>

<script>
	class HnToggle extends HTMLElement {
		#btn = this.querySelector<HTMLAnchorElement>('a')!;
		#toggleOpen = this.toggleOpen.bind(this);

		connectedCallback() {
			this.#btn.addEventListener('click', this.#toggleOpen, false);
		}

		disconnectedCallback() {
			this.#btn.addEventListener('click', this.#toggleOpen);
		}

		get open() {
			return this.hasAttribute('open');
		}

		set open(value: boolean) {
			if (value) {
				this.setAttribute('open', '');
				this.#btn.textContent = '[-]';
			} else {
				this.removeAttribute('open');
				this.#btn.textContent = '[+] comments collapsed';
			}
		}

		toggleOpen() {
			this.open = !this.open;
		}
	}

	customElements.define('hn-toggle', HnToggle);
</script>